codebase / stimlib

  #ifndef STIM_IMAGE_H
  #define STIM_IMAGE_H

  #ifdef JPEG_FOUND
  	#define cimg_use_jpeg         //necessary for JPG files
  #endif

  #include "CImg.h"
  

  #include <vector>

  #include <iostream>

  namespace stim{

  //This static class provides the STIM interface for loading images
  //	Use this interface for all image management - that way the actual library can be changed without problems
  
  //currently this interface uses CImg
  //	T = data type (usually unsigned char)
  template <class T>
  class image{
  

  	cimg_library::CImg<T> img;

  
  public:
  

  	//default constructor
  	image(){
  	}
  
  	//constructor (load an image file)
  	image(std::string filename){
  		img.load(filename.c_str());
  	}
  

  	/// Constructor initializes an image to a given size
  	image(unsigned int x, unsigned int y = 1, unsigned int z = 1){
  		img = cimg_library::CImg<T>(x, y, z);
  	}
  

  	//Load an image from a file
  	void load(std::string filename){

  		img.load(filename.c_str());

  	}
  
  	//save a file
  	void save(std::string filename){

  		img.save(filename.c_str());

  	}
  

  	//create an image from an interleaved buffer

  	void set_interleaved(T* buffer, unsigned int width, unsigned int height, unsigned int channels = 1){
  
  		unsigned char* non_interleaved = (unsigned char*)malloc(width * height * 3);
  		unsigned int S = width * height;
  
  		for(unsigned int i = 0; i < S; i++){
  			for(unsigned int c = 0; c < channels; c++){
  				non_interleaved[i + c * S] = buffer[i * channels + c];
  			}
  		}

  		img = cimg_library::CImg<unsigned char>(non_interleaved, width, height, 1, channels);
  	}
  

  	//fills an allocated region of memory with non-interleaved data

  	void data_noninterleaved(T* data){
  		memcpy(data, img.data(), sizeof(T) * size());
  	}
  
  	void data_interleaved(T* data){
  
  		unsigned int C = channels();

  		unsigned int X = width() * height();

  
  		T* ptr = img.data();
  
  		//for each channel
  		for(unsigned int c = 0; c < C; c++)
  			//convert each pixel
  			for(unsigned int x = 0; x < X; x++)
  				data[x * C + c] = ptr[c * X + x];
  	}
  

  	image<T> channel(unsigned int c){
  
  		//create a new image
  		image<T> single;
  
  		single.img = img.channel(c);
  
  		return single;
  
  	}
  

  	unsigned int channels(){
  		return (unsigned int)img.spectrum();
  	}
  
  	unsigned int width(){
  		return img.width();
  	}
  
  	unsigned int height(){
  		return img.height();

  	}

  	//returns the size (number of values) of the image
  	unsigned long size(){
  		return img.size();

  	}
  

  	/// Returns the number of nonzero values
  	unsigned int nnz(){
  
  		unsigned long P = width() * height();
  		unsigned long C = channels();
  
  		T* ptr = img.data();
  
  		unsigned long n = 0;
  
  		for(unsigned long p = 0; p < P; p++){
  			for(unsigned long c = 0; c < C; c++){
  
  				if(ptr[c * P + p] > 0){
  					n++;
  					break;
  				}
  			}
  		}
  
  		return n;	//return the number of nonzero pixels
  
  	}
  
  	//this function returns indices of pixels that have nonzero values
  	std::vector<unsigned long> sparse_idx(){
  
  		std::vector<unsigned long> s;		//allocate an array
  		s.resize(nnz());					//allocate space in the array
  
  		unsigned long P = width() * height();
  		unsigned long C = channels();
  
  		T* ptr = img.data();				//get a pointer to the image data
  
  		unsigned long i = 0;
  		for(unsigned long p = 0; p < P; p++){
  			for(unsigned long c = 0; c < C; c++){
  
  				if(ptr[c * P + p] > 0){
  					s[i] = p;
  					i++;
  					break;
  				}
  			}
  		}
  
  		return s;			//return the index list
  	}

  	
  
  
  
  };
  

  };		//end namespace stim
  

  
  #endif