Differential D25318 Diff 69829 kstars/fitsviewer/stretch.h

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kstars/fitsviewer/stretch.h

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		1		/* Stretch
		2
		3		This application is free software; you can redistribute it and/or
		4		modify it under the terms of the GNU General Public
		5		License as published by the Free Software Foundation; either
		6		version 2 of the License, or (at your option) any later version.
		7		*/
		8
		9		#pragma once
		10
		11		#include <memory>
		12		#include <QImage>
		13
		14		struct StretchParams1Channel
		15		{
		16		// Stretch algorithm parameters
		17		float shadows;;
		18		float highlights;
		19		float midtones;
		20		// The extension parameters are not yet used.
		21		float shadows_expansion;
		22		float highlights_expansion;
		23
		24		// The default parameters result in no stretch at all.
		25		StretchParams1Channel()
		26		{
		27		shadows = 0.0;
		28		highlights = 1.0;
		29		midtones = 0.5;
		30		shadows_expansion = 0.0;
		31		highlights_expansion = 1.0;
		32		}
		33		};
		34
		35		struct StretchParams
		36		{
		37		StretchParams1Channel grey_red, green, blue;
		38		};
		39
		40		template <typename T>
		41		class Stretch
		42		{
		43		public:
		44		/**
		45		* @brief Stretch Constructor for Stretch class
		46		* @param image_buffer pointer to the image memory
		47		* @param width the image width
		48		* @param height the image height
		49		* @param channels should be 1 or 3
		50		* @note The image should either be 1-channel or 3-channel
		51		* The image buffer is not copied, so it should not be deleted while the object is in use
		52		*/
		53		explicit Stretch(T * image_buffer, int width, int height, int channels);
		54		~Stretch() {}
		55
		56		/**
		57		* @brief setParams Sets the stretch parameters.
		58		* @param param The desired parameter values.
		59		* @note This set method used for both 1-channel and 3-channel images.
		60		* In 1-channel images, the _g and _b parameters are ignored.
		61		* The parameter scale is 0-1 for all data types.
		62		*/
		63		void setParams(StretchParams input_params) { params = input_params; }
		64
		65		/**
		66		* @brief getParams Returns the stretch parameters (computed by computeParameters()).
		67		*/
		68		StretchParams getParams() { return params; }
		69
		70		/**
		71		* @brief computeParams Automatically generates and sets stretch parameters from the image.
		72		*/
		73		StretchParams computeParams();
		74
		75		/**
		76		* @brief run run the stretch algorithm according to the params given
		77		* placing the output in output_image.
		78		*/
		79		void run(QImage *output_image);
		80
		81		private:
		82		// Inputs.
		83		T *buffer;
		84		int image_width;
		85		int image_height;
		86		int image_channels;
		87		int input_range;
		88
		89		// Parameters.
		90		StretchParams params;
		91		};