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# An attempt to address the PIL.Image buffer directly without copying it.
#
# This is achieved by extracting the buffer ptr from Image.im.unsafe_ptrs
# the xsize, ysize, pixelsize and linesize are extracted as well to be used
# in TessBaseAPI.SetImage(buffer, width, height, bytes_per_pixel, bytes_per_line)
#
# This works but for sometimes the output is different than the original code. I assume
# this is due to the different image format used in this method.
#
# The performance advantage was not significant based on benchmarks on my machine.
from libc.stdint cimport uintptr_t
cdef object _mode_to_bpp = {'1':1, 'L':8, 'P':8, 'RGB':24, 'RGBA':32, 'CMYK':32, 'YCbCr':24, 'I':32, 'F':32}
cdef void _image_buffer2(image, cuchar_t **buff, int *width, int *height,
int *bpp, int *bpl):
"""Read image meta data from unsafe pointers."""
cdef uintptr_t buff_ptr
# get buffer from unsafe pointers without copying it
image.load()
ptrs = dict(image.im.unsafe_ptrs)
width[0] = ptrs['xsize']
height[0] = ptrs['ysize']
buff_ptr = ptrs['image']
buff[0] = (<cuchar_t **>buff_ptr)[0]
bpp[0] = ptrs['pixelsize']
bpl[0] = ptrs['linesize']
# for f in ptrs:
# name = f[0]
# if name == 'xsize': # width
# width[0] = f[1]
# elif name == 'ysize': # height
# height[0] = f[1]
# elif name == 'image': # buffer address
# buff_ptr = f[1]
# buff[0] = (<cuchar_t **>buff_ptr)[0]
# elif name == 'pixelsize': # bytes_per_pixel
# bpp[0] = f[1]
# elif name == 'linesize': # bytes_per_line
# bpl[0] = f[1]
cdef char *_image_to_text2(const unsigned char *buff, int width, int height, int bpp, int bpl,
const char *lang,
const PageSegMode pagesegmode, const char *path) nogil except NULL:
cdef:
TessBaseAPI baseapi
char *text
if baseapi.Init(path, lang) == -1:
return NULL
baseapi.SetPageSegMode(pagesegmode)
baseapi.SetImage(buff, width, height, bpp, bpl)
text = baseapi.GetUTF8Text()
baseapi.End()
return text
def image_to_text2(image, const char *lang=_DEFAULT_LANG, const PageSegMode pagesegmode=PSM_AUTO,
const char *path=_DEFAULT_PATH):
"""Recognize OCR text from an image object.
Args:
image (:class:`PIL.Image`): image to be processed.
Kwargs:
lang (str): An ISO 639-3 language string. Defaults to 'eng'.
pagesegmode (int): Page segmentation mode. Defaults to `PSM.AUTO`.
See :class:`~tesserocr.PSM` for all available psm options.
path (str): The name of the parent directory of tessdata.
Must end in /.
Returns:
str: The text extracted from the image.
Raises:
RuntimeError: When image fails to be loaded or recognition fails.
"""
cdef:
cuchar_t *buff = NULL
int width = 0
int height = 0
int bpp = 0
int bpl = 0
char *text
_image_buffer2(image, &buff, &width, &height, &bpp, &bpl)
# print width, height
# print bpp
# print bpl
with nogil:
text = _image_to_text2(buff, width, height, bpp, bpl,
lang, pagesegmode, path)
if text == NULL:
with gil:
raise RuntimeError('Failed to recognize image text.')
return _free_str(text)
cdef Pix *raw_to_pix(cuchar_t *buff, int bpp, int width, int height, int bpl) nogil:
"""Convert PIL image to Pix.
Applies the same logic done by tesseract's api.SetImage."""
cdef:
int x
int y
int wpl
uint *data
Pix *pix
bpp = bpp * 8
pix = pixCreate(width, height, 32 if bpp == 24 else bpp)
wpl = pixGetWpl(pix)
data = pixGetData(pix)
if bpp == 8:
# Greyscale just copies the bytes in the right order.
for y in xrange(height):
for x in xrange(width):
SET_DATA_BYTE(data, x, buff[x])
data += wpl
buff += bpl
elif bpp == 24:
# Put the colors in the correct places in the line buffer.
for y in xrange(height):
for x in xrange(width):
SET_DATA_BYTE(data, COLOR_RED, buff[3 * x])
SET_DATA_BYTE(data, COLOR_GREEN, buff[3 * x + 1])
SET_DATA_BYTE(data, COLOR_BLUE, buff[3 * x + 2])
data += 1
buff += bpl
elif bpp == 32:
# Maintain byte order consistency across different endianness.
for y in xrange(height):
for x in xrange(width):
data[x] = (buff[x * 4] << 24) | (buff[x * 4 + 1] << 16) | (buff[x * 4 + 2] << 8) | buff[x * 4 + 3]
data += wpl
buff += bpl
else:
with gil:
raise RuntimeError("Cannot convert RAW image to Pix with bpp = {}".format(bpp))
return pix
def image_to_text3(image, const char *lang=_DEFAULT_LANG, const PageSegMode psm=PSM_AUTO,
const char *path=_DEFAULT_PATH):
cdef:
Pix *pix
cuchar_t *buff = NULL
int width = 0
int height = 0
int bpp = 0
int bpl = 0
char *text
_image_buffer2(image, &buff, &width, &height, &bpp, &bpl)
with nogil:
pix = raw_to_pix(buff, bpp, width, height, bpl)
text = _image_to_text(pix, lang, psm, path)
if text == NULL:
with gil:
raise RuntimeError('Failed recognize picture')
return _free_str(text)
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