88 lines
2.5 KiB
C++
88 lines
2.5 KiB
C++
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#include <iostream>
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#include "bloomshader.h"
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Bloomshader::Bloomshader(CImg<float> image) : image(image) {}
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CImg<float> Bloomshader::bloom(float threshold, int kernelSize, float sigma, float intensity) {
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// Apply threshold to image
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//CImg<float> brightPixels = image_.get_threshold(threshold);
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//brightPixels.save("brightpixels.png");
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// Apply gaussian blur to bright pixels
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CImg<float> kernel = computeGaussianKernel(kernelSize, sigma);
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CImg<float> blurred = convolution(image, kernel);
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for(int i = 0; i < 3; i++){
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kernel = computeGaussianKernel(kernelSize, sigma);
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blurred = convolution(image, kernel);
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blurred *= intensity;
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}
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// Add blurred image back to original image
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cimg_forXYC(image, x, y, c) {
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float value = image(x,y,0,c) + blurred(x,y,0,c);
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image(x,y,0,c) = (value > 1.0f) ? 1.0f : value;
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}
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return image;
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}
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void Bloomshader::gaussianBlur(int kernelSize, float sigma) {
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CImg<float> kernel = computeGaussianKernel(kernelSize, sigma);
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image = convolution(image, kernel);
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}
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// Function to compute Gaussian kernel
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CImg<float> Bloomshader::computeGaussianKernel(int kernelSize, float sigma) {
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// Create kernel
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CImg<float> kernel(kernelSize, kernelSize, 1, 1);
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// Compute Gaussian kernel
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float sum = 0.0f;
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int i, j;
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for (i = 0; i < kernelSize; i++) {
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for (j = 0; j < kernelSize; j++) {
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kernel(i, j) = exp(-0.5f * (pow((i - kernelSize / 2.f) / sigma, 2.f) +
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pow((j - kernelSize / 2.f) / sigma, 2.f))) / (2 * M_PI * sigma * sigma);
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sum += kernel(i, j);
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}
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}
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// Normalize kernel
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kernel /= sum;
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return kernel;
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}
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// Function to perform convolution
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CImg<float> Bloomshader::convolution(CImg<float> &img, CImg<float> &kernel) {
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int kernelSize = kernel.width();
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int imgRows = img.height();
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int imgCols = img.width();
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CImg<float> result(imgCols, imgRows, 1, 3);
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float sum;
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int i, j, m, n;
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int kernelRadius = kernelSize / 2;
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// Perform convolution
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cimg_forXYC(img, i, j, c) {
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sum = 0;
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cimg_forY(kernel, m) {
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cimg_forX(kernel, n) {
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int x = i + n - kernelRadius;
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int y = j + m - kernelRadius;
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if(x >= 0 && x < imgCols && y >= 0 && y < imgRows){
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sum += img(x, y, 0, c) * kernel(n, m);
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}
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}
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}
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result(i, j, 0, c) = sum;
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}
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return result;
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}
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void Bloomshader::scaleBrightness(float scale) {
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image *= scale;
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}
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