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\title{ImageMagick - Interactively Display and Edit an Image}
\toctitle{ImageMagick - Interactively Display and Edit an Image}
\titlerunning{ImageMagick - Interactively Display and Edit an Image}
\maketitle\label{ImageMagick - Interactively Display and Edit an Image}

\section{NAME}

display - display an image on any workstation running X


\section{Synopsis}

{\bf display} {\bf [} {\it options\/} {\bf ...]} {\it file\/}
{\bf [}{\it options\/}{\bf ...]}{\it file\/}

\section{Description}

Display is a machine architecture independent
image processing and display program. It can display an image on any workstation
screen running an X server. {\bf Display} can read and write
{\bf many}
of the more popular image formats (e.g. {\bf JPEG},
{\bf TIFF},
{\bf PNM},
{\bf Photo
CD}, etc.).

With {\bf display}, you can perform these functions on an image:
\begin{description}
\item{load an image from a file}
\item{display the next image}
\item{display the former image}
\item{display a sequence of images as a slide show}
\item{write the image to a file}
\item{print the image to a {\it PostScript\/} printer}
\item{delete the image file}
\item{create a Visual Image Directory}
\item{select the image to display by its thumbnail rather than name}
\item{undo last image transformation}
\item{copy a region of the image}
\item{paste a region to the image}
\item{restore the image to its original size}
\item{refresh the image}
\item{half the image size}
\item{double the image size}
\item{resize the image}
\item{crop the image}
\item{cut the image}
\item{flop image in the horizontal direction}
\item{flip image in the vertical direction}
\item{rotate the image 90 degrees clockwise}
\item{rotate the image 90 degrees counter-clockwise}
\item{rotate the image}
\item{shear the image}
\item{roll the image}
\item{trim the image edges}
\item{invert the colors of the image}
\item{vary the color brightness}
\item{vary the color saturation}
\item{vary the image hue}
\item{gamma correct the image}
\item{sharpen the image contrast}
\item{dull the image contrast}
\item{perform histogram equalization on the image}
\item{perform histogram normalization on the image}
\item{negate the image colors}
\item{convert the image to grayscale}
\item{set the maximum number of unique colors in the image}
\item{reduce the speckles within an image}
\item{eliminate peak noise from an image}
\item{detect edges within the image}
\item{emboss an image}
\item{segment the image by color}
\item{simulate an oil painting}
\item{simulate a charcoal drawing}
\item{annotate the image with text}
\item{draw on the image}
\item{edit an image pixel color}
\item{edit the image matte information}
\item{composite an image with another}
\item{add a border to the image}
\item{surround image with an ornamental border}
\item{apply image processing techniques to a region of interest}
\item{display information about the image}
\item{zoom a portion of the image}
\item{show a histogram of the image}
\item{display image to background of a window}
\item{set user preferences}
\item{display information about this program}
\item{discard all images and exit program}
\item{change the level of magnification}
\item{display images specified by a World Wide Web (WWW) uniform resource locator (URL)}
\end{description}


\section{Examples}

To scale an image of a cockatoo to exactly 640 pixels in width and 480
pixels in height and position the window at location (200,200), use:
\begin{verbatim}
    display -geometry 640x480+200+200! cockatoo.miff
\end{verbatim}

To display an image of a cockatoo without a border centered on a backdrop,
use:
\begin{verbatim}
    display +borderwidth -backdrop cockatoo.miff
\end{verbatim}

To tile a slate texture onto the root window, use:
\begin{verbatim}
    display -size 1280x1024 -window root slate.png
\end{verbatim}

To display a visual image directory of all your JPEG images, use:
\begin{verbatim}
    display 'vid:*.jpg'
\end{verbatim}

To display a MAP image that is 640 pixels in width and 480 pixels in height
with 256 colors, use:
\begin{verbatim}
    display -size 640x480+256 cockatoo.map
\end{verbatim}

To display an image of a cockatoo specified with a {\bf World Wide Web (WWW)}
uniform resource locator {\bf (URL)}, use:
\begin{verbatim}
    display ftp://wizards.dupont.com/images/cockatoo.jpg
\end{verbatim}

To display histogram of an image, use:
\begin{verbatim}
    convert file.jpg HISTOGRAM:- | display -
\end{verbatim}


\section{Options}

Options are processed in command line order. Any option you specify on
the command line remains in effect until it is explicitly changed by specifying
the option again with a different effect. For example to display three images,
the first with 32 colors, the second with an unlimited number of colors,
and the third with only 16 colors, use:
\begin{verbatim}
      display -colors 32 cockatoo.miff -noop duck.miff
              -colors 16 macaw.miff
\end{verbatim}

{\bf Display} options can appear on the command line or in your X resources
file. See {\it X(1)\/}. Options on the command line supersede values specified
in your X resources file.

For a more detailed description of each option, see
{\it ImageMagick(1)\/}.


\subsubsection{-authenticate $<$string$>$}
decrypt image with this password
\subsubsection{-backdrop $<$color$>$}
display the image centered on a backdrop.
\subsubsection{-background $<$color$>$}
the background color
\subsubsection{-border $<$width$>$x$<$height$>$}
surround the image with a border of color
\subsubsection{-bordercolor $<$color$>$}
the border color
\subsubsection{-borderwidth $<$geometry$>$}
the border width
\subsubsection{-channel $<$type$>$}
Red, Green, Blue, Opacity, Index, Cyan, Yellow, Magenta, Black, or All.

Use this option to apply an image-processing option to a particular
{\it channel\/} from the image.
\subsubsection{-colormap $<$type$>$}
define the colormap type
\subsubsection{-colors $<$value$>$}
preferred number of colors in the image
\subsubsection{-colorspace $<$value$>$}
the type of colorspace
\subsubsection{-comment $<$string$>$}
annotate an image with a comment
\subsubsection{-compress $<$type$>$}
the type of image compression
\subsubsection{-contrast}
enhance or reduce the image contrast
\subsubsection{-crop $<$width$>$x$<$height$>$\{+-\}$<$x$>$\{+-\}$<$y$>$\{\%\}}
preferred size and location of the cropped image
\subsubsection{-debug $<$events$>$}
enable debug printout
\subsubsection{-delay $<$1/100ths of a second$>$}
display the next image after pausing
\subsubsection{-density $<$width$>$x$<$height$>$}
vertical and horizontal resolution in pixels of the image
\subsubsection{-depth $<$value$>$}
depth of the image
\subsubsection{-despeckle}
reduce the speckles within an image
\subsubsection{-display $<$host:display[.screen]$>$}
specifies the X server to contact
\subsubsection{-dispose $<$method$>$}
GIF disposal method
\subsubsection{-dither}
apply Floyd/Steinberg error diffusion to the image
\subsubsection{-edge $<$radius$>$}
detect edges within an image
\subsubsection{-endian $<$type$>$}
specify endianness (MSB or LSB) of output image
\subsubsection{-enhance}
apply a digital filter to enhance a noisy image
\subsubsection{-extract $<$width$>$x$<$height$>$\{+-\}$<$x$>$\{+-\}$<$y$>$\{\%\}\{@\} \{{!}\}\{$<$\}\{$>$\}}
extract an area from the image while decoding
\subsubsection{-filter $<$type$>$}
use this type of filter when resizing an image
\subsubsection{-flip}
create a ``mirror image''
\subsubsection{-flop}
create a ``mirror image''
\subsubsection{-font $<$name$>$}
use this font when annotating the image with text
\subsubsection{-foreground $<$color$>$}
define the foreground color
\subsubsection{-frame $<$width$>$x$<$height$>$+$<$outer bevel width$>$+$<$inner bevel width$>$}
surround the image with an ornamental border
\subsubsection{-gamma $<$value$>$}
level of gamma correction
\subsubsection{-geometry $<$width$>$x$<$height$>$\{+-\}$<$x$>$\{+-\}$<$y$>$\{\%\}\{@\} \{{!}\}\{$<$\}\{$>$\}}
preferred size and location of the Image window.
\subsubsection{-help}
print usage instructions
\subsubsection{-iconGeometry $<$geometry$>$}
specify the icon geometry
\subsubsection{-iconic}
iconic animation
\subsubsection{-immutable}
make image immutable
\subsubsection{-interlace $<$type$>$}
the type of interlacing scheme
\subsubsection{-label $<$name$>$}
assign a label to an image
\subsubsection{-limit $<$type$>$ $<$value$>$}
Disk, File, Map, or Memory resource limit
\subsubsection{-log $<$string$>$}
\subsubsection{-magnify $<$factor$>$}
magnify the image
\subsubsection{-map $<$type$>$}

display image using this type.
\subsubsection{-matte}
store matte channel if the image has one
\subsubsection{-mattecolor $<$color$>$}
specify the color to be used with the {\bf -frame} option
\subsubsection{-monochrome}
transform the image to black and white
\subsubsection{-name}
name an image
\subsubsection{-negate}
replace every pixel with its complementary color
\subsubsection{-noop}
NOOP (no option)
\subsubsection{-page $<$width$>$x$<$height$>$\{+-\}$<$x$>$\{+-\}$<$y$>$\{\%\}\{{!}\}\{$<$\}\{$>$\}}
size and location of an image canvas
\subsubsection{-quality $<$value$>$}
JPEG/MIFF/PNG compression level
\subsubsection{-raise $<$width$>$x$<$height$>$}
lighten or darken image edges
\subsubsection{-remote}
perform a remote operation
\subsubsection{-roll \{+-\}$<$x$>$\{+-\}$<$y$>$}
roll an image vertically or horizontally
\subsubsection{-rotate $<$degrees$>$\{$<$\}\{$>$\}}
apply Paeth image rotation to the image
\subsubsection{-sample $<$geometry$>$}
scale image with pixel sampling
\subsubsection{-sampling-factor $<$horizontal\_factor$>$x$<$vertical\_factor$>$}
sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.
\subsubsection{-scenes $<$value-value$>$}
range of image scene numbers to read
\subsubsection{-segment $<$cluster threshold$>$x$<$smoothing threshold$>$}
segment an image
\subsubsection{-shared-memory}
use shared memory
\subsubsection{-sharpen $<$radius$>$\{x$<$sigma$>$\}}
sharpen the image
\subsubsection{-size $<$width$>$x$<$height$>$\{+offset\}}
width and height of the image
\subsubsection{-text-font $<$name$>$}
font for writing fixed-width text
\subsubsection{-texture $<$filename$>$}
name of texture to tile onto the image background
\subsubsection{-title $<$string$>$}
assign title to displayed image [{\it animate, display, montage\/}]
\subsubsection{-treedepth $<$value$>$}
tree depth for the color reduction algorithm
\subsubsection{-trim}
trim an image
\subsubsection{-update $<$seconds$>$}

detect when image file is modified and redisplay.
\subsubsection{-use-pixmap}
use the pixmap
\subsubsection{-verbose}
print detailed information about the image
\subsubsection{-version}
print ImageMagick version string
\subsubsection{-visual $<$type$>$}
animate images using this X visual type
\subsubsection{-window $<$id$>$}
make image the background of a window
\subsubsection{-window-group}
specify the window group
\subsubsection{-write $<$filename$>$}
write the image to a file [{\it display\/}]

For a more detailed description of each option, see
{\it ImageMagick(1)\/}.



\section{Mouse Buttons}

The effects of each button press is described below. Three buttons are
required. If you have a two button mouse, button 1 and 3 are returned.
Press {\bf ALT} and button 3 to simulate button 2.
\subsubsection{1}

Press this button to map or unmap the Command
widget . See the next section for more information about the Command
widget.
\subsubsection{2}

Press and drag to define a region of the image to magnify.
\subsubsection{3}

Press and drag to choose from a select set of {\bf display(1)}
commands. This button behaves differently if the image being displayed
is a visual image directory. Choose a particular tile of the directory
and press this button and drag to select a command from a pop-up menu.
Choose from these menu items:
{\begin{description}
\item{Open}
\item{Next}
\item{Former}
\item{Delete}
\item{Update}
\end{description}}

If you choose {\bf Open}, the image represented by the tile is displayed.
To return to the visual image directory, choose {\bf Next} from the Command
widget (refer to Command Widget).
{\bf Next} and {\bf Former}
moves to the next or former image respectively. Choose {\bf Delete} to
delete a particular image tile. Finally, choose {\bf Update} to synchronize
all the image tiles with their respective images. See
montage
and
miff for more details.


\section{Command Widget}

The Command widget lists a number of sub-menus and commands. They are
{\begin{description}
\item{{\bf File}
{\begin{description}
\item{Open...}
\item{Next}
\item{Former}
\item{Select...}
\item{Save...}
\item{Print...}
\item{Delete...}
\item{Canvas...}
\item{Visual Directory...}
\item{Quit}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf Edit}
{\begin{description}
\item{Undo}
\item{Redo}
\item{Cut}
\item{Copy}
\item{Paste}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf View}
{\begin{description}
\item{Half Size}
\item{Original Size}
\item{Double Size}
\item{Resize...}
\item{Apply}
\item{Refresh}
\item{Restore}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf Transform}
{\begin{description}
\item{Crop}
\item{Chop}
\item{Flop}
\item{Flip}
\item{Rotate Right}
\item{Rotate Left}
\item{Rotate...}
\item{Shear...}
\item{Roll...}
\item{Trim Edges}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf Enhance}
{\begin{description}
\item{Hue...}
\item{Saturation...}
\item{Brightness...}
\item{Gamma...}
\item{Spiff...}
\item{Dull}
\item{Equalize}
\item{Normalize}
\item{Negate}
\item{GRAYscale}
\item{Quantize...}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf Effects}
{\begin{description}
\item{Despeckle}
\item{Emboss}
\item{Reduce Noise}
\item{Add Noise}
\item{Sharpen...}
\item{Blur...}
\item{Threshold...}
\item{Edge Detect...}
\item{Spread...}
\item{Shade...}
\item{Raise...}
\item{Segment...}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf F/X}
{\begin{description}
\item{Solarize...}
\item{Swirl...}
\item{Implode...}
\item{Wave...}
\item{Oil Paint...}
\item{Charcoal Draw...}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf Image Edit}
{\begin{description}
\item{Annotate...}
\item{Draw...}
\item{Color...}
\item{Matte...}
\item{Composite...}
\item{Add Border...}
\item{Add Frame...}
\item{Comment...}
\item{Launch...}
\item{Region of Interest...}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf Miscellany}
{\begin{description}
\item{Image Info}
\item{Zoom Image}
\item{Show Preview...}
\item{Show Histogram}
\item{Show Matte}
\item{Background...}
\item{Slide Show}
\item{Preferences...}
\end{description}}}
\end{description}}
{\begin{description}
\item{{\bf Help}}
{\begin{description}
\item{Overview}
\item{Browse Documentation}
\item{About Display}
\end{description}}
\end{description}}

Menu items with a indented triangle have a sub-menu. They are represented
above as the indented items. To access a sub-menu item, move the pointer
to the appropriate menu and press button 1 and drag. When you find the
desired sub-menu item, release the button and the command is executed.
Move the pointer away from the sub-menu if you decide not to execute a
particular command.


\section{Keyboard Accelerators}

Accelerators are one or two key presses that effect a particular command.
The keyboard accelerators that
{\bf display} understands is:
\begin{verbatim}
    Ctl+O     Press to <a href="#imlo">load</a> an image from a file.
    space     Press to display the next image.
\end{verbatim}

If the image is a multi-paged document such as a
{\it PostScript\/} document,
you can skip ahead several pages by preceding this command with a number.
For example to display the fourth page beyond the current page,
press {\tt 4space}.
\begin{verbatim}
    backspace Press to display the former image.
\end{verbatim}

If the image is a multi-paged document such as a
{\it PostScript\/} document,
you can skip behind several pages by preceding this command with a number.
For example to display the fourth page preceding the current page, press
4n.
\begin{verbatim}
    Ctl-S    Press to save the image to a file.
    Ctl-P    Press to print the image to a
             <i>PostScript</i> printer.
    Ctl-D    Press to delete an image file.
    Ctl-N    Press to create a blank canvas.
    Ctl-Q    Press to discard all images and exit program.
    Ctl+Z    Press to undo last image transformation.
    Ctl+R    Press to redo last image transformation.
    Ctl-X    Press to <a href="#imcu">cut</a> a region of
             the image.
    Ctl-C    Press to <a href="#imco">copy</a> a region of
             the image.
    Ctl-V    Press to <a href="#impa">paste</a> a region to
             the image.
    <        Press to halve the image size.
    .        Press to return to the original image size.
    >        Press to double the image size.
    %        Press to resize the image to a width and height
             you specify.
    Cmd-A    Press to make any image transformations permanent.
             By default, any image size transformations are
             applied to the original image to create the image
             displayed on the X server.  However, the
             transformations are not permanent (i.e. the original
             image does not change size only the X image does).
             For example, if you press ">" the X image will
             appear to double in size, but the original image
             will in fact remain the same size.  To force the
             original image to double in size, press ">" followed
             by "Cmd-A".
    @        Press to refresh the image window.
    C        Press to <a href="#imcr">crop</a> the image.
    [        Press to <a href="#imch">chop</a> the image.
    H        Press to flop image in the horizontal direction.
    V        Press to flip image in the vertical direction.
    /        Press to rotate the image 90 degrees clockwise.
    \        Press to rotate the image 90 degrees
             counter-clockwise.
    *        Press to <a href="#imro">rotate</a> the image
             the number of degrees you specify.
    S        Press to shear the image the number of degrees
             you specify.
    R        Press to roll the image.
    T        Press to trim the image edges.
    Shft-H   Press to vary the color hue.
    Shft-S   Press to vary the color saturation.
    Shft-L   Press to vary the image brightness.
    Shft-G   Press to gamma correct the image.
    Shft-C   Press to spiff up the image contrast.
    Shft-Z   Press to dull the image contrast.
    =        Press to perform histogram equalization on
             the image.
    Shft-N   Press to perform histogram normalization on
             the image.
    Shft-~   Press to negate the colors of the image.
    .        Press to convert the image colors to gray.
    Shft-#   Press to set the maximum number of unique
             colors in the image.
    F2       Press to reduce the speckles in an image.
    F2       Press to emboss an image.
    F4       Press to eliminate peak noise from an image.
    F5       Press to add noise to an image.
    F6       Press to sharpen an image.
    F7       Press to blur image an image.
    F8       Press to threshold the image.
    F9       Press to detect edges within an image.
    F10      Press to displace pixels by a random amount.
    F11      Press to shade the image using a distant light
             source.
    F12      Press to lighten or darken image edges to create
             a 3-D effect.
    F13      Press to segment the image by color.
    Meta-S   Press to swirl image pixels about the center.
    Meta-I   Press to implode image pixels about the center.
    Meta-W   Press to alter an image along a sine wave.
    Meta-P   Press to simulate an oil painting.
    Meta-C   Press to simulate a charcoal drawing.
    Alt-X    Press to <a href="#imcomp">composite</a> the image
             with another.
    Alt-A    Press to <a href="#iman">annotate</a> the image with text.
    Alt-D    Press to <a href="#imdr">draw</a> a line on the image.
    Alt-P    Press to <a href="#cole">edit an image pixel color</a>.
    Alt-M    Press to <a href="#matt">edit the image matte</a> information.
    Alt-X    Press to <a href="#imcomp">composite</a> the image with another.
    Alt-A    Press to add a border to the image.
    Alt-F    Press to add a ornamental frame to the image.
    Alt-Shft-!   Press to add an image comment.
    Ctl-A    Press to apply image processing techniques to a
             region of interest.
    Shft-?   Press to display information about the image.
    Shft-+   Press to map the zoom image window.
    Shft-P   Press to preview an image enhancement, effect,
             or f/x.
    F1       Press to display helpful information about
             the "display" utility.
    Find     Press to browse documentation about ImageMagick.
    1-9      Press to change the level of magnification.
\end{verbatim}

Use the arrow keys to move the image one pixel up, down, left, or right
within the magnify window. Be sure to first map the magnify window by pressing
button 2.

Press ALT and one of the arrow keys to trim off one pixel from any side
of the image.


\section{X Resources}

{\bf Display} options can appear on the command line or in your X resource
file. Options on the command line supersede values specified in your X
resource file. See {\it X(1)\/} for more information on X resources.

Most {\bf display} options have a corresponding X resource. In addition,
{\bf display}
uses the following X resources:
\subsubsection{background (class Background)}

Specifies the preferred color to use for the Image window background. The
default is \#ccc.
\subsubsection{borderColor (class BorderColor)}

Specifies the preferred color to use for the Image window border. The default
is \#ccc.
\subsubsection{borderWidth (class BorderWidth)}

Specifies the width in pixels of the image window border. The default is
2.
\subsubsection{browseCommand (class browseCommand)}

Specifies the name of the preferred browser when displaying ImageMagick
documentation. The default is {\tt netscape \%s}.
\subsubsection{confirmExit (class ConfirmExit)}

{\bf Display} pops up a dialog box to confirm exiting the program when
exiting the program. Set this resource to {\tt False} to exit without
a confirmation.
\subsubsection{displayGamma (class DisplayGamma)}

Specifies the gamma of the X server.

You can apply separate gamma values to the red, green, and blue channels
of the image with a gamma value list delineated with slashes (i.e. 1.7/2.3/1.2).

The default is 2.2.
\subsubsection{displayWarnings (class DisplayWarnings)}

{\bf Display} pops up a dialog box whenever a warning message occurs.
Set this resource to {\tt False} to ignore warning messages.
\subsubsection{font (class FontList)}

Specifies the name of the preferred font to use in normal formatted text.
The default is 14 point Helvetica.
\subsubsection{font[1-9] (class Font[1-9])}

Specifies the name of the preferred font to use when
annotating
the image window with text. The default fonts are fixed, variable, 5x8,
6x10, 7x13bold, 8x13bold, 9x15bold, 10x20, and 12x24.
\subsubsection{foreground (class Foreground)}

Specifies the preferred color to use for text within the image window.
The default is black.
\subsubsection{gammaCorrect (class gammaCorrect)}

This resource, if true, will lighten or darken an image of known gamma
to match the gamma of the display (see resource {\bf displayGamma}). The
default is True.
\subsubsection{geometry (class Geometry)}

Specifies the preferred size and position of the image window. It is not
necessarily obeyed by all window managers.

Offsets, if present, are handled in {\it X(1)\/} style.  A negative x offset is
measured from the right edge of the screen to the right edge of the icon,
and a negative y offset is measured from the bottom edge of the screen
to the bottom edge of the icon.
\subsubsection{iconGeometry (class IconGeometry)}

Specifies the preferred size and position of the application when iconified.
It is not necessarily obeyed by all window managers.

Offsets, if present, are handled in the same manner as in class Geometry.
\subsubsection{iconic (class Iconic)}

This resource indicates that you would prefer that the application's windows
initially not be visible as if the windows had be immediately iconified
by you. Window managers may choose not to honor the application's request.
\subsubsection{magnify (class Magnify)}

specifies an integral factor by which the image should be enlarged. The
default is 3.

This value only affects the magnification window which is invoked with
button
number 3 after the image is displayed.
\subsubsection{matteColor (class MatteColor)}

Specify the color of windows. It is used for the backgrounds of windows,
menus, and notices. A 3D effect is achieved by using highlight and shadow
colors derived from this color. Default value: \#697B8F.
\subsubsection{name (class Name)}

This resource specifies the name under which resources for the application
should be found. This resource is useful in shell aliases to distinguish
between invocations of an application, without resorting to creating links
to alter the executable file name. The default is the application name.
\subsubsection{pen[1-9] (class Pen[1-9])}

Specifies the color of the preferred font to use when
annotating
the image window with text. The default colors are black, blue, green,
cyan, gray, red, magenta, yellow, and white.
\subsubsection{printCommand (class PrintCommand)}

This command is executed whenever Print is issued.  In general, it is the
command to print {\it PostScript\/} to your printer. Default value: {\tt lp
-c -s \%i}.
\subsubsection{sharedMemory (class SharedMemory)}

This resource specifies whether display should attempt use shared memory
for pixmaps. ImageMagick must be compiled with shared memory support, and
the display must support the MIT-SHM extension. Otherwise, this resource
is ignored. The default is True.
\subsubsection{textFont (class textFont)}

Specifies the name of the preferred font to use in fixed (typewriter style)
formatted text. The default is 14 point Courier.
\subsubsection{title (class Title)}

This resource specifies the title to be used for the image window. This
information is sometimes used by a window manager to provide a header identifying
the window. The default is the image file name.
\subsubsection{undoCache (class UndoCache)}

Specifies, in mega-bytes, the amount of memory in the undo edit cache.
Each time you modify the image it is saved in the undo edit cache as long
as memory is available. You can subsequently {\it undo\/} one or more of
these transformations. The default is 16 Megabytes.
\subsubsection{usePixmap (class UsePixmap)}

Images are maintained as a XImage by default. Set this resource to True
to utilize a server Pixmap instead. This option is useful if your image
exceeds the dimensions of your server screen and you intend to pan the
image. Panning is much faster with Pixmaps than with a XImage. Pixmaps
are considered a precious resource, use them with discretion.

To set the geometry of the Magnify or Pan or window, use the geometry resource.
For example, to set the Pan window geometry to 256x256, use:
\begin{verbatim}
    display.pan.geometry: 256x256
\end{verbatim}


\section{Image Loading}

To select an image to display, choose {\bf Open} of the {\bf File} sub-menu
from the Command widget. A file browser is displayed.
To choose a particular image file, move the pointer to the filename and
press any button. The filename is copied to the text window. Next, press
{\bf Open}
or press the {\bf RETURN} key. Alternatively, you can type the image file
name directly into the text window. To descend directories, choose a directory
name and press the button twice quickly. A scrollbar allows a large list
of filenames to be moved through the viewing area if it exceeds the size
of the list area.

You can trim the list of file names by using shell globbing characters.
For example, type {\tt *.jpg} to list only files that end
with {\tt .jpg}.

To select your image from the X server screen instead of from a file, Choose
{\bf Grab} of the {\bf Open} widget.


\section{Visual Image Directory}

To create a Visual Image Directory, choose Visual Directory of the {\bf File}
sub-menu from the Command widget . A file browser is
displayed. To create a Visual Image Directory from all the images in the
current directory, press {\bf Directory} or press the {\bf RETURN key}.
Alternatively, you can select a set of image names by using shell globbing
characters. For example, type {\tt *.jpg} to include only files that
end with {\tt .jpg}. To descend directories, choose a directory name
and press the button twice quickly. A scrollbar allows a large list of
filenames to be moved through the viewing area if it exceeds the size of
the list area.

After you select a set of files, they are turned into thumbnails and tiled
onto a single image. Now move the pointer to a particular thumbnail and
press {\bf button 3} and drag. Finally, select Open. The image represented
by the thumbnail is displayed at its full size. Choose {\bf Next} from
the {\bf File} sub-menu of the Command widget to return to the Visual
Image Directory.


\section{Image Cutting}

Note that cut information for image window is not retained for colormapped
X server visuals (e.g. {\it StaticColor\/},
{\it StaticColor\/}, {\it GRAYScale\/},
{\it PseudoColor\/}).
Correct cutting behavior may require a {\it TrueColor\/} or {\it DirectColor\/}
visual or a {\it Standard Colormap\/}.

To begin, press choose {\bf Cut} of the {\bf Edit} sub-menu from the
Command
widget. Alternatively, press
{\bf F3} in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in cut mode. In cut mode, the Command widget has these
options:
{\begin{description}
\item{{\bf Help}}
\item{{\bf Dismiss}}
\end{description}}

To define a cut region, press button 1 and drag. The cut region is defined
by a highlighted rectangle that expands or contracts as it follows the
pointer. Once you are satisfied with the cut region, release the button.
You are now in rectify mode. In rectify mode, the Command widget has these
options:
{\begin{description}
\item{{\bf Cut}}
\item{{\bf Help}}
\item{{\bf Dismiss}}
\end{description}}

You can make adjustments by moving the pointer to one of the cut rectangle
corners, pressing a button, and dragging. Finally, press Cut to commit
your copy region. To exit without cutting the image, press Dismiss.


\section{Image Copying}

To begin, press choose {\bf Copy} of the {\bf Edit} sub-menu from the
Command
widget. Alternatively, press
{\bf F4} in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in copy mode. In copy mode, the Command widget has
these options:
{\begin{description}
\item{Help}
\item{Dismiss}
\end{description}}

To define a copy region, press button 1 and drag. The copy region is defined
by a highlighted rectangle that expands or contracts as it follows the
pointer. Once you are satisfied with the copy region, release the button.
You are now in rectify mode. In rectify mode, the Command widget has these
options:
{\begin{description}
\item{Copy}
\item{Help}
\item{Dismiss}
\end{description}}

You can make adjustments by moving the pointer to one of the copy rectangle
corners, pressing a button, and dragging. Finally, press Copy to commit
your copy region. To exit without copying the image, press Dismiss.


\section{Image Pasting}

To begin, press choose {\bf Paste} of the {\bf Edit} sub-menu from the
Command
widget. Alternatively, press
{\bf F5} in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in Paste mode. To exit immediately, press Dismiss.
In Paste mode, the Command widget has these options:
{\begin{description}
\item{{\bf Operators}
{\begin{description}
\item{over}
\item{in}
\item{out}
\item{atop}
\item{xor}
\item{plus}
\item{minus}
\item{add}
\item{subtract}
\item{difference}
\item{multiply}
\item{bumpmap}
\item{replace}
\end{description}}}
\item{{\bf Help}}
\item{{\bf Dismiss}}
\end{description}}

Choose a composite operation from the {\bf Operators} sub-menu of the
Command
widget. How each operator behaves is described below. {\it image window\/}
is the image currently displayed on your X server and {\it image\/} is the
image obtained with the File Browser widget.
\subsubsection{over}

The result is the union of the two image shapes, with {\it image\/} obscuring
{\it image
window\/} in the region of overlap.
\subsubsection{in}

The result is simply {\it image\/} cut by the shape of
{\it image window\/}.
None of the image data of image window is in the result.
\subsubsection{out}

The resulting image is {\it image\/} with the shape of
{\it image window\/}
cut out.
\subsubsection{atop}

The result is the same shape as {\it image window\/}, with
{\it image\/}
obscuring {\it image window\/} where the image shapes overlap. Note this
differs from over because the portion of image outside
{\it image window\/}'s
shape does not appear in the result.
\subsubsection{xor}

The result is the image data from both {\it image\/} and
{\it image window\/}
that is outside the overlap region. The overlap region is blank.
\subsubsection{plus}

The result is just the sum of the image data. Output values are cropped
to MaxRGB (no overflow). This operation is independent of the matte channels.
\subsubsection{minus}

The result of {\it image\/} - {\it image window\/}, with underflow cropped
to zero.
\subsubsection{add}

The result of {\it image\/} + {\it image window\/}, with overflow wrapping
around (mod MaxRGB).
\subsubsection{subtract}

The result of {\it image\/} - {\it image window\/}, with underflow wrapping
around (mod (MaxRGB+1)). The add and subtract operators can be used to perform
reversible transformations.
\subsubsection{difference}

The result of abs({\it image\/} - {\it image window\/}). This is useful for
comparing two very similar images.
\subsubsection{multiply}

The result of {\it image\/} * {\it image window\/}. This is useful for
the creation of drop-shadows.
\subsubsection{bumpmap}

The result of {\it image window\/} shaded by {\it window\/}.
\subsubsection{replace}
The resulting image is {\it image window\/} replaced with
{\it image\/}.
Here the matte information is ignored.

The image compositor requires a matte, or alpha channel in the image for
some operations. This extra channel usually defines a mask which represents
a sort of a cookie-cutter for the image. This is the case when matte is
opaque (full coverage) for pixels inside the shape, zero outside, and between
0 and MaxRGB on the boundary. If image does not have a matte channel, it
is initialized with 0 for any pixel matching in color to pixel location
(0,0), otherwise MaxRGB. See Matte Editing for a method
of defining a matte channel.

Note that matte information for image window is not retained for colormapped
X server visuals (e.g. {\it StaticColor, StaticColor, GrayScale, PseudoColor\/}).
Correct compositing behavior may require a
{\it TrueColor\/} or {\it DirectColor\/}
visual or a {\it Standard Colormap\/}.

Choosing a composite operator is optional. The default operator is replace.
However, you must choose a location to composite your image and press button
1. Press and hold the button before releasing and an outline of the image
will appear to help you identify your location.

The actual colors of the pasted image is saved. However, the color that
appears in image window may be different. For example, on a monochrome
screen image window will appear black or white even though your pasted
image may have many colors. If the image is saved to a file it is written
with the correct colors. To assure the correct colors are saved in the
final image, any {\it PseudoClass\/} image is promoted to {\it DirectClass\/}.
To force a
{\it PseudoClass\/} image to remain {\it PseudoClass\/},
use {\bf -colors}.


\section{Image Cropping}

To begin, press choose {\bf Crop} of the {\bf Transform} submenu from
the Command widget. Alternatively,
press [ in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in crop mode. In crop mode, the Command widget has
these options:
{\begin{description}
\item{{\bf Help}}
\item{{\bf Dismiss}}
\end{description}}

To define a cropping region, press button 1 and drag. The cropping region
is defined by a highlighted rectangle that expands or contracts as it follows
the pointer. Once you are satisfied with the cropping region, release the
button. You are now in rectify mode. In rectify mode, the Command widget
has these options:
{\begin{description}
\item{{\bf Crop}}
\item{{\bf Help}}
\item{{\bf Dismiss}}
\end{description}}

You can make adjustments by moving the pointer to one of the cropping rectangle
corners, pressing a button, and dragging. Finally, press Crop to commit
your cropping region. To exit without cropping the image, press Dismiss.


\section{Image Chopping}

An image is chopped interactively. There is no command line argument to
chop an image. To begin, choose {\bf Chop} of the {\bf Transform} sub-menu
from the Command widget. Alternatively,
press ] in the Image window.

You are now in {\bf Chop} mode. To exit immediately, press
{\bf Dismiss}.
In Chop mode, the Command widget has these options:
{\begin{description}
\item{{\bf Direction}
{\begin{description}
\item{horizontal}
\item{vertical}
\end{description}}}
\item{{\bf Help}}
\item{{\bf Dismiss}}
\end{description}}

If the you choose the horizontal direction (this is the default), the area
of the image between the two horizontal endpoints of the chop line is removed.
Otherwise, the area of the image between the two vertical endpoints of
the chop line is removed.

Select a location within the image window to begin your chop, press and
hold any button. Next, move the pointer to another location in the image.
As you move a line will connect the initial location and the pointer. When
you release the button, the area within the image to chop is determined
by which direction you choose from the Command widget.

To cancel the image chopping, move the pointer back to the starting point
of the line and release the button.


\section{Image Rotation}

Press the / key to rotate the image 90 degrees or \ to rotate -90 degrees.
To interactively choose the degree of rotation, choose
{\bf Rotate...}
of the {\bf Transform} submenu from the Command Widget.
Alternatively, press * in the image window.

A small horizontal line is drawn next to the pointer. You are now in rotate
mode. To exit immediately, press Dismiss. In rotate mode, the Command widget
has these options:
{\begin{description}
\item{{\bf Pixel Color}
{\begin{description}
\item{black}
\item{blue}
\item{cyan}
\item{green}
\item{gray}
\item{red}
\item{magenta}
\item{yellow}
\item{white}
\item{Browser...}
\end{description}}}
\item{{\bf Direction}
{\begin{description}
\item{horizontal}
\item{vertical}
\end{description}}}
\item{{\bf Help}}
\item{{\bf Dismiss}}
\end{description}}

Choose a background color from the Pixel Color sub-menu. Additional background
colors can be specified with the color browser. You can change the menu
colors by setting the X resources pen1 through pen9.

If you choose the color browser and press {\bf Grab}, you can select the
background color by moving the pointer to the desired color on the screen
and press any button.

Choose a point in the image window and press this button and hold. Next,
move the pointer to another location in the image. As you move a line connects
the initial location and the pointer. When you release the button, the
degree of image rotation is determined by the slope of the line you just
drew. The slope is relative to the direction you choose from the Direction
sub-menu of the Command widget.

To cancel the image rotation, move the pointer back to the starting point
of the line and release the button.


\section{Image Segmentation}

Choose {\bf Effects-$>$Segment} to segment an image by analyzing the histograms
of the color components and identifying units that are homogeneous with
the fuzzy c-means technique. The scale-space filter analyzes the histograms
of the three color components of the image and identifies a set of classes.
The extents of each class is used to coarsely segment the image with thresholding.
The color associated with each class is determined by the mean color of
all pixels within the extents of a particular class. Finally, any unclassified
pixels are assigned to the closest class with the fuzzy c-means technique.
The fuzzy c-Means algorithm can be summarized as follows:
{\begin{description}
\item{
Build a histogram, one for each color component of the image.}
\item{
For each histogram, successively apply the scale-space filter and build
an interval tree of zero crossings in the second derivative at each scale.
Analyze this scale-space ``fingerprint'' to determine which peaks or valleys
in the histogram are most predominant.}
\item{
The fingerprint defines intervals on the axis of the histogram. Each interval
contains either a minima or a maxima in the original signal. If each color
component lies within the maxima interval, that pixel is considered ``classified''
and is assigned an unique class number.}
\item{
Any pixel that fails to be classified in the above thresholding pass is
classified using the fuzzy c-Means technique. It is assigned to one of
the classes discovered in the histogram analysis phase.}
\end{description}}

The fuzzy c-Means technique attempts to cluster a pixel by finding the
local minima of the generalized within group sum of squared error objective
function. A pixel is assigned to the closest class of which the fuzzy membership
has a maximum value.

For additional information see:
{\it Young Won Lim, Sang Uk Lee\/}, "{\bf On The Color Image Segmentation
Algorithm Based on the Thresholding and the Fuzzy c-Means Techniques}",
Pattern Recognition, Volume 23, Number 9, pages 935-952, 1990.



\section{Image Annotation}

An image is annotated interactively. There is no command line argument
to annotate an image. To begin, choose
{\bf Annotate} of the {\bf Image
Edit} sub-menu from the Command widget. Alternatively,
press a in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in annotate mode. To exit immediately, press Dismiss.
In annotate mode, the Command widget has these options:
{\begin{description}
\item{
{\bf Font Name}
{\begin{description}
\item{
fixed}
\item{
variable}
\item{
5x8}
\item{
6x10}
\item{
7x13bold}
\item{
8x13bold}
\item{
9x15bold}
\item{
10x20}
\item{
12x24}
\item{
Browser...}
\end{description}}}
\item{
{\bf Font Color}
{\begin{description}
\item{
black}
\item{
blue}
\item{
cyan}
\item{
green}
\item{
gray}
\item{
red}
\item{
magenta}
\item{
yellow}
\item{
white}
\item{
transparent}
\item{
Browser...}
\end{description}}}
\item{
{\bf Box Color}
{\begin{description}
\item{
black}
\item{
blue}
\item{
cyan}
\item{
green}
\item{
gray}
\item{
red}
\item{
magenta}
\item{
yellow}
\item{
white}
\item{
transparent}
\item{
Browser...}
\end{description}}}
\item{
{\bf Rotate Text}
{\begin{description}
\item{
-90}
\item{
-45}
\item{
-30}
\item{
0}
\item{
30}
\item{
45}
\item{
90}
\item{
180}
\item{
Dialog...}
\end{description}}}
\item{
{\bf Help}}
\item{
{\bf Dismiss}}
\end{description}}

Choose a font name from the {\bf Font Name} sub-menu. Additional font
names can be specified with the font browser. You can change the menu names
by setting the X resources font1 through font9.

Choose a font color from the {\bf Font Color} sub-menu. Additional font
colors can be specified with the color browser. You can change the menu
colors by setting the X resources pen1 through pen9.

If you select the color browser and press {\bf Grab}, you can choose the
font color by moving the pointer to the desired color on the screen and
press any button.

If you choose to rotate the text, choose {\bf Rotate Text} from the menu
and select an angle. Typically you will only want to rotate one line of
text at a time. Depending on the angle you choose, subsequent lines may
end up overwriting each other.

Choosing a font and its color is optional. The default font is fixed and
the default color is black. However, you must choose a location to begin
entering text and press a button. An underscore character will appear at
the location of the pointer. The cursor changes to a pencil to indicate
you are in text mode. To exit immediately, press Dismiss.

In text mode, any key presses will display the character at the location
of the underscore and advance the underscore cursor. Enter your text and
once completed press Apply to finish your image annotation. To correct
errors press {\bf BACK SPACE}. To delete an entire line of text, press
{\bf DELETE}.
Any text that exceeds the boundaries of the image window is automatically
continued onto the next line.

The actual color you request for the font is saved in the image. However,
the color that appears in your Image window may be different. For example,
on a monochrome screen the text will appear black or white even if you
choose the color red as the font color. However, the image saved to a file
with {\bf -write} is written with red lettering. To assure the correct
color text in the final image, any {\it PseudoClass\/} image is promoted
to {\it DirectClass\/} (see miff(5)). To force a {\it PseudoClass\/} image
to remain
{\it PseudoClass\/}, use {\bf -colors}.


\section{Image Compositing}

An image composite is created interactively. {\bf There is no command line
argument to composite an image}. To begin, choose {\bf Composite} of
the {\bf Image Edit} from the Command widget. Alternatively,
press x in the Image window.

First a popup window is displayed requesting you to enter an image name.
Press {\bf Composite}, {\bf Grab} or type a file name. Press {\bf Cancel}
if you choose not to create a composite image. When you choose {\bf Grab},
move the pointer to the desired window and press any button.

If the {\bf Composite} image does not have any matte information, you
are informed and the file browser is displayed again. Enter the name of
a mask image. The image is typically grayscale and the same size as the
composite image. If the image is not grayscale, it is converted to grayscale
and the resulting intensities are used as matte information.

A small window appears showing the location of the cursor in the image
window. You are now in composite mode. To exit immediately, press Dismiss.
In composite mode, the Command widget has these options:
{\begin{description}
\item{
{\bf Operators}
{\begin{description}
\item{
over}
\item{
in}
\item{
out}
\item{
atop}
\item{
xor}
\item{
plus}
\item{
minus}
\item{
add}
\item{
subtract}
\item{
difference}
\item{
bumpmap}
\item{
replace}
\end{description}}}
\item{
{\bf Blend}}
\item{
{\bf Displace}}
\item{
{\bf Help}}
\item{
{\bf Dismiss}}
\end{description}}

Choose a composite operation from the Operators sub-menu of the Command
widget. How each operator behaves is described below. image window is the
image currently displayed on your X server and image is the image obtained
\subsubsection{over}

The result is the union of the two image shapes, with {\it image\/} obscuring
{\it image
window\/} in the region of overlap.
\subsubsection{in}

The result is simply {\it image\/} cut by the shape of
{\it image window\/}.
None of the image data of image window is in the result.
\subsubsection{out}

The resulting image is {\it image\/} with the shape of
{\it image window\/}
cut out.
\subsubsection{atop}

The result is the same shape as {\it image window\/}, with
{\it image\/}
obscuring {\it image window\/} where the image shapes overlap. Note this
differs from over because the portion of image outside
{\it image window\/}'s
shape does not appear in the result.
\subsubsection{xor}

The result is the image data from both {\it image\/} and
{\it image window\/}
that is outside the overlap region. The overlap region is blank.
\subsubsection{plus}

The result is just the sum of the image data. Output values are cropped
to MaxRGB (no overflow).
\subsubsection{minus}

The result of {\it image\/} - {\it image window\/}, with underflow cropped
to zero.
\subsubsection{add}

The result of {\it image\/} + {\it image window\/}, with overflow wrapping
around (mod (MaxRGB+1)).
\subsubsection{subtract}

The result of {\it image\/} - {\it image window\/}, with underflow wrapping
around (mod (MaxRGB+1)). The add and subtract operators can be used to perform
reversible transformations.
\subsubsection{difference}

The result of abs({\it image\/} - {\it image window\/}). This is useful for
comparing two very similar images.
\subsubsection{bumpmap}

The result of {\it image window\/} shaded by {\it window\/}.
\subsubsection{replace}

The resulting image is {\it image window\/} replaced with
{\it image\/}.
Here the matte information is ignored.

The image compositor requires a matte, or alpha channel in the image for
some operations. This extra channel usually defines a mask which represents
a sort of a cookie-cutter for the image. This is the case when matte is
opaque (full coverage) for pixels inside the shape, zero outside, and between
0 and MaxRGB on the boundary. If image does not have a matte channel, it
is initialized with 0 for any pixel matching in color to pixel location
(0,0), otherwise MaxRGB. See Matte Editing for a method
of defining a matte channel.

If you choose {\bf blend}, the composite operator becomes {\bf over}.
The image matte channel percent transparency is initialized to factor.
The image window is initialized to (100-factor). Where factor is the value
you specify in the Dialog widget.

{\bf Displace} shifts the image pixels as defined by a displacement map.
With this option, {\it image\/} is used as a displacement map. Black, within
the displacement map, is a maximum positive displacement. White is a maximum
negative displacement and middle gray is neutral. The displacement is scaled
to determine the pixel shift. By default, the displacement applies in both
the horizontal and vertical directions. However, if you specify
{\it mask\/},
{\it image\/}
is the horizontal X displacement and
{\it mask\/} the vertical Y displacement.

Note that matte information for image window is not retained for colormapped
X server visuals (e.g.
{\it StaticColor, StaticColor, GrayScale, PseudoColor\/}).
Correct compositing behavior may require a {\it TrueColor\/} or
{\it DirectColor\/}
visual or a {\it Standard Colormap\/}.

Choosing a composite operator is optional. The default operator is replace.
However, you must choose a location to composite your image and press button
1. Press and hold the button before releasing and an outline of the image
will appear to help you identify your location.

The actual colors of the composite image is saved. However, the color that
appears in image window may be different. For example, on a monochrome
screen Image window will appear black or white even though your composited
image may have many colors. If the image is saved to a file it is written
with the correct colors. To assure the correct colors are saved in the
final image, any PseudoClass image is promoted to {\it DirectClass\/} (see
miff).
To force a {\it PseudoClass\/} image to remain {\it PseudoClass\/},
use {\bf -colors}.


\section{Color Editing}

Changing the the color of a set of pixels is performed interactively. There
is no command line argument to edit a pixel. To begin, choose {\bf Color}
from the {\bf Image Edit} submenu of the Command widget.
Alternatively, press c in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in color edit mode. To exit immediately, press {\bf Dismiss}.
In color edit mode, the
{\bf Command widget} has these options:
{\begin{description}
\item{
{\bf Method}
{\begin{description}
\item{
point}
\item{
replace}
\item{
floodfill}
\item{
reset}
\end{description}}}
\item{
{\bf Pixel Color}
{\begin{description}
\item{
black}
\item{
blue}
\item{
cyan}
\item{
green}
\item{
gray}
\item{
red}
\item{
magenta}
\item{
yellow}
\item{
white}
\item{
Browser...}
\end{description}}}
\item{
{\bf Border Color}
{\begin{description}
\item{
black}
\item{
blue}
\item{
cyan}
\item{
green}
\item{
gray}
\item{
red}
\item{
magenta}
\item{
yellow}
\item{
white}
\item{
Browser...}
\end{description}}}
\item{
{\bf Fuzz}
{\begin{description}
\item{
0}
\item{
2}
\item{
4}
\item{
8}
\item{
16}
\item{Dialog...}
\end{description}}}
\item{
{\bf Undo}}
\item{
{\bf Help}}
\item{
{\bf Dismiss}}
\end{description}}

Choose a color editing method from the {\bf Method} sub-menu of
the Command
widget. The {\bf point method} recolors any pixel selected with the
pointer unless the button is released. The {\bf replace method} recolors
any pixel that matches the color of the pixel you select with a button
press. {\bf Floodfill} recolors any pixel that matches the color of the
pixel you select with a button press and is a neighbor.
Whereas {\bf filltoborder}
changes the matte value of any neighbor pixel that is not the border color.
Finally {\bf reset} changes the entire image to the designated color.

Next, choose a pixel color from the {\bf Pixel Color} sub-menu. Additional
pixel colors can be specified with the color browser. You can change the
menu colors by setting the X resources pen1 through
pen9.

Now press button 1 to select a pixel within the Image window to change
its color. Additional pixels may be recolored as prescribed by the method
you choose. additional pixels by increasing the Delta value.

If the {\bf Magnify widget} is mapped, it can be helpful in positioning
your pointer within the image (refer to button 2). Alternatively you can
select a pixel to recolor from within the {\bf Magnify widget}. Move the
pointer to the {\bf Magnify widget} and position the pixel with the cursor
control keys. Finally, press a button to recolor the selected pixel (or
pixels).

The actual color you request for the pixels is saved in the image. However,
the color that appears in your Image window may be different. For example,
on a monochrome screen the pixel will appear black or white even if you
choose the color red as the pixel color. However, the image saved to a
file with -write is written with red pixels. To assure the correct color
text in the final image, any {\it PseudoClass\/} image is promoted
to {\it DirectClass\/}
To force a {\it PseudoClass\/} image to remain
{\it PseudoClass\/}, use {\bf -colors}.


\section{Matte Editing}

Matte information within an image is useful for some operations such as
image compositing. This extra channel usually defines
a mask which represents a sort of a cookie-cutter for the image. This is
the case when matte is opaque (full coverage) for pixels inside the shape,
zero outside, and between 0 and MaxRGB on the boundary.

Setting the matte information in an image is done interactively. There
is no command line argument to edit a pixel. To begin, and choose {\bf Matte}
of the {\bf Image Edit} sub-menu from the Command widget.

Alternatively, press m in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in matte edit mode. To exit immediately, press Dismiss.
In matte edit mode, the Command widget has these options:
{\begin{description}
\item{
{\bf Method}
{\begin{description}
\item{
point}
\item{
replace}
\item{
floodfill}
\item{
reset}
\end{description}}}
\item{
{\bf Border Color}
{\begin{description}
\item{
black}
\item{
blue}
\item{
cyan}
\item{
green}
\item{
gray}
\item{
red}
\item{
magenta}
\item{
yellow}
\item{
white}
\item{
Browser...}
\end{description}}}
\item{
{\bf Fuzz}
{\begin{description}
\item{
0}
\item{
2}
\item{
4}
\item{
8}
\item{
16}
\item{Dialog...}
\end{description}}}
\item{
{\bf Matte}}
\item{
{\bf Undo}}
\item{
{\bf Help}}
\item{
{\bf Dismiss}}
\end{description}}
Choose a matte editing method from the {\bf Method} sub-menu of the Command
widget. The {\bf point method} changes the matte value of the any
pixel selected with the pointer until the button is released. The {\bf replace
method} changes the matte value of any pixel that matches the color
of the pixel you select with a button press. {\bf Floodfill} changes the
matte value of any pixel that matches the color of the pixel you select
with a button press and is a neighbor. Whereas
{\bf filltoborder} recolors
any neighbor pixel that is not the border color. Finally {\bf reset} changes
the entire image to the designated matte value.
Choose {\bf Matte Value} and a dialog appears requesting a matte value.
Enter a value between {\bf 0 and MaxRGB}. This value is assigned as the matte
value of the selected pixel or pixels.
Now, press any button to select a pixel within the Image window to change
its matte value. You can change the matte value of additional pixels by
increasing the Delta value. The Delta value is first added then subtracted
from the red, green, and blue of the target color. Any pixels within the
range also have their matte value updated.
If the {\bf Magnify widget} is mapped, it can be helpful in positioning
your pointer within the image (refer to button 2). Alternatively you can
select a pixel to change the matte value from within the
{\bf Magnify widget}.
Move the pointer to the {\bf Magnify widget} and position the pixel with
the cursor control keys. Finally, press a button to change the matte value
of the selected pixel (or pixels).
Matte information is only valid in a {\it DirectClass image\/}. Therefore,
any {\it PseudoClass\/} image is promoted to
{\it DirectClass\/}. Note that
matte information for {\it PseudoClass\/} is not retained for colormapped
X server visuals (e.g. {\it StaticColor, StaticColor, GrayScale, PseudoColor\/})
unless you immediately save your image to a file (refer to Write). Correct
matte editing behavior may require a {\it TrueColor\/} or {\it DirectColor\/}
visual or a {\it Standard Colormap\/}.


\section{Image Drawing}

An image is drawn upon interactively. {\bf There is no command line argument
to draw on an image}. To begin, choose {\bf Draw} of the Image {\bf Edit}
sub-menu from the Command widget.
Alternatively, press d in the image window.

The cursor changes to a crosshair to indicate you are in draw mode. To
exit immediately, press Dismiss. In draw mode, the Command widget has these
options:
{\begin{description}
\item{
{\bf Primitive}
{\begin{description}
\item{
point}
\item{
line}
\item{
rectangle}
\item{
fill rectangle}
\item{
circle}
\item{
fill circle}
\item{
ellipse}
\item{
fill ellipse}
\item{
polygon}
\item{
fill polygon}
\end{description}}}
\item{
{\bf Color}
{\begin{description}
\item{
black}
\item{
blue}
\item{
cyan}
\item{
green}
\item{
gray}
\item{
red}
\item{
magenta}
\item{
yellow}
\item{
white}
\item{
transparent}
\item{
Browser...}
\end{description}}}
\item{
{\bf Stipple}
{\begin{description}
\item{
Brick}
\item{
Diagonal}
\item{
Scales}
\item{
Vertical}
\item{
Wavy}
\item{
Translucent}
\item{
Opaque}
\item{
Open...}
\end{description}}}
\item{
{\bf Width}
{\begin{description}
\item{
1}
\item{
2}
\item{
4}
\item{
8}
\item{
16}
\item{Dialog...}
\end{description}}}
\item{
{\bf Undo}}
\item{
{\bf Help}}
\item{
{\bf Dismiss}}
\end{description}}
Choose a drawing primitive from the {\bf Primitive} sub-menu.

Next, choose a color from the {\bf Color} sub-menu. Additional colors
can be specified with the color browser. You can change the menu colors
by setting the X resources pen1 through pen9. The transparent
color updates the image matte channel and is useful for image compositing.

If you choose the color browser and press {\bf Grab}, you can select the
primitive color by moving the pointer to the desired color on the screen
and press any button. The transparent color updates the image matte channel
and is useful for image compositing.

Choose a stipple, if appropriate, from the {\bf Stipple} sub-menu. Additional
stipples can be specified with the file browser. Stipples obtained from
the file browser must be on disk in the X11 bitmap format.

Choose a line width, if appropriate, from the {\bf Width} sub-menu. To
choose a specific width select the {\bf Dialog} widget.

Choose a point in the image window and press button 1 and hold. Next, move
the pointer to another location in the image. As you move, a line connects
the initial location and the pointer. When you release the button, the
image is updated with the primitive you just drew. For polygons, the image
is updated when you press and release the button without moving the pointer.

To cancel image drawing, move the pointer back to the starting point of
the line and release the button.


\section{Region of Interest}

To begin, press choose Region of Interest of the Pixel Transform sub-menu
from the Command widget.
Alternatively, press R in the image window.

A small window appears showing the location of the cursor in the image
window. You are now in region of interest mode. In region of interest mode,
the Command widget has these options:
{\begin{description}
\item{
{\bf Help}}
\item{
{\bf Dismiss}}
\end{description}}

To define a region of interest, press button 1 and drag. The region of
interest is defined by a highlighted rectangle that expands or contracts
as it follows the pointer. Once you are satisfied with the region of interest,
release the button. You are now in apply mode. In apply mode the Command
widget has these options:
{\begin{description}
\item{
{\bf File}
{\begin{description}
\item{
Save...}
\item{
Print...}
\end{description}}}
\item{
{\bf Edit}
{\begin{description}
\item{
Undo}
\item{
Redo}
\end{description}}}
\item{
{\bf Transform}
{\begin{description}
\item{
Flip}
\item{
Flop}
\item{
Rotate Right}
\item{
Rotate Left}
\end{description}}}
\item{
{\bf Enhance}
{\begin{description}
\item{
Hue...}
\item{
Saturation...}
\item{
Brightness...}
\item{
Gamma...}
\item{
Spiff}
\item{
Dull}
\item{
Equalize}
\item{
Normalize}
\item{
Negate}
\item{
GRAYscale}
\item{
Quantize...}
\end{description}}}
\item{
{\bf Effects}
{\begin{description}
\item{
Despeckle}
\item{
Emboss}
\item{
Reduce Noise}
\item{
Add Noise}
\item{
Sharpen...}
\item{
Blur...}
\item{
Threshold...}
\item{
Edge Detect...}
\item{
Spread...}
\item{
Shade...}
\item{
Raise...}
\item{
Segment...}
\end{description}}}
\end{description}}
{\begin{description}
\item{
{\bf F/X}
{\begin{description}
\item{
Solarize...}
\item{
Swirl...}
\item{
Implode...}
\item{
Wave...}
\item{
Oil Paint}
\item{
Charcoal Draw...}
\end{description}}}
\end{description}}
{\begin{description}
\item{
{\bf Miscellany}
{\begin{description}
\item{
Image Info}
\item{
Zoom Image}
\item{
Show Preview...}
\item{
Show Histogram}
\item{
Show Matte}
\end{description}}}
\item{
{\bf Help}}
\item{
{\bf Dismiss}}
\end{description}}

You can make adjustments to the region of interest by moving the pointer
to one of the rectangle corners, pressing a button, and dragging. Finally,
choose an image processing technique from the Command widget. You can choose
more than one image processing technique to apply to an area. Alternatively,
you can move the region of interest before applying another image processing
technique. To exit, press Dismiss.


\section{Image Panning}

When an image exceeds the width or height of the X server screen, display
maps a small panning icon. The rectangle within the panning icon shows
the area that is currently displayed in the the image window. To pan about
the image, press any button and drag the pointer within the panning icon.
The pan rectangle moves with the pointer and the image window is updated
to reflect the location of the rectangle within the panning icon. When
you have selected the area of the image you wish to view, release the button.

Use the arrow keys to pan the image one pixel up, down, left, or right
within the image window.

The panning icon is withdrawn if the image becomes smaller than the dimensions
of the X server screen.


\section{User Preferences}

Preferences affect the default behavior of {\bf display(1)}. The preferences
are either true or false and are stored in your home directory
as {\tt .displayrc}:
\begin{description}
\item{
{\bf display image centered on a backdrop}}

This backdrop covers the entire workstation screen and is useful for hiding
other X window activity while viewing the image. The color of the backdrop
is specified as the background color. Refer to X Resources
for details.
\item{
{\bf confirm on program exit}}

Ask for a confirmation before exiting the {\bf display(1)} program.
\item{
{\bf correct image for display gamma}}

If the image has a known gamma, the gamma is corrected to match that of
the X server (see the X Resource{\bf  displayGamma}).
\item{
{\bf display warning messages}}

Display any warning messages.
\item{
{\bf apply Floyd/Steinberg error diffusion to image}}

The basic strategy of dithering is to trade intensity resolution for spatial
resolution by averaging the intensities of several neighboring pixels.
Images which suffer from severe contouring when reducing colors can be
improved with this preference.
\item{
{\bf use a shared colormap for colormapped X visuals}}

This option only applies when the default X server visual is
{\it PseudoColor\/}
or {\it GRAYScale\/}. Refer to {\bf -visual} for more details. By default,
a shared colormap is allocated. The image shares colors with other X clients.
Some image colors could be approximated, therefore your image may look
very different than intended. Otherwise the image colors appear exactly
as they are defined. However, other clients may go technicolor when the
image colormap is installed.
\item{
{\bf display images as an X server pixmap}}

Images are maintained as a XImage by default. Set this resource to True
to utilize a server Pixmap instead. This option is useful if your image
exceeds the dimensions of your server screen and you intend to pan the
image. Panning is much faster with Pixmaps than with a XImage. Pixmaps
are considered a precious resource, use them with discretion.
\end{description}


\section{Environment}
\subsubsection{DISPLAY}
To get the default host, display number, and screen.


\section{Acknowledgements}

The {\bf MIT X Consortium} for making network transparent graphics a
reality.

{\it Peder Langlo\/}, {\bf Hewlett Packard}, Norway, made hundreds of suggestions
and bug reports. Without Peder, {\bf ImageMagick} would not be nearly
as useful as it is today.

{\it Rod Bogart\/} and {\it John W. Peterson\/}, {\bf University of Utah}.
Image compositing is loosely based on rlecomp of the Utah Raster Toolkit.

{\it Michael Halle\/}, {\bf Spatial Imaging Group at MIT}, for the initial
implementation of Alan Paeth's image rotation algorithm.

{\it David Pensak\/}, {\bf ImageMagick Studio}, for providing a computing
environment that made this program possible.

{\it Paul Raveling\/}, {\bf USC Information Sciences Institute}. The
spatial subdivision color reduction algorithm is based on his Img software.


\section{Authors}

{\it 
John Cristy, ImageMagick Studio LLC,\newline{}
Glenn Randers-Pehrson, ImageMagick Studio LLC.
\/}