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/* Stretch
This application is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
*/
#pragma once
//Qt Includes
#include <QImage>
//System Includes
#include <memory>
struct StretchParams1Channel
{
// Stretch algorithm parameters
float shadows;;
float highlights;
float midtones;
// The extension parameters are not yet used.
float shadows_expansion;
float highlights_expansion;
// The default parameters result in no stretch at all.
StretchParams1Channel()
{
shadows = 0.0;
highlights = 1.0;
midtones = 0.5;
shadows_expansion = 0.0;
highlights_expansion = 1.0;
}
};
struct StretchParams
{
StretchParams1Channel grey_red, green, blue;
};
class Stretch
{
public:
/**
* @brief Stretch Constructor for Stretch class
* @param image_buffer pointer to the image memory
* @param width the image width
* @param height the image height
* @param channels should be 1 or 3
* @note The image should either be 1-channel or 3-channel
* The image buffer is not copied, so it should not be deleted while the object is in use
*/
explicit Stretch(int width, int height, int channels, int data_type);
~Stretch() {}
/**
* @brief setParams Sets the stretch parameters.
* @param param The desired parameter values.
* @note This set method used for both 1-channel and 3-channel images.
* In 1-channel images, the _g and _b parameters are ignored.
* The parameter scale is 0-1 for all data types.
*/
void setParams(StretchParams input_params) { params = input_params; }
/**
* @brief getParams Returns the stretch parameters (computed by computeParameters()).
*/
StretchParams getParams() { return params; }
/**
* @brief computeParams Automatically generates and sets stretch parameters from the image.
*/
StretchParams computeParams(uint8_t *input);
/**
* @brief run run the stretch algorithm according to the params given
* placing the output in output_image.
* @param input the raw data buffer.
* @param output_image a QImage pointer that should be the same size as the input if
* sampling is 1 otherwise, the proper size if the input is downsampled by sampling.
* @param sampling The sampling parameter. Applies to both width and height.
* Sampling is applied to the output (that is, with sampling=2, we compute every other output
* sample both in width and height, so the output would have about 4X fewer pixels.
*/
void run(uint8_t *input, QImage *output_image, int sampling=1);
private:
// Adjusts input_range for float and double types.
void recalculateInputRange(uint8_t *input);
// Inputs.
int image_width;
int image_height;
int image_channels;
int input_range;
int dataType;
// Parameters.
StretchParams params;
};
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