70 lines
1.6 KiB
C++
70 lines
1.6 KiB
C++
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#include "bin_niblack.h"
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#include "transformation.h"
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BinarizationNiblack::BinarizationNiblack(PNM* img) :
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Transformation(img)
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{
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}
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BinarizationNiblack::BinarizationNiblack(PNM* img, ImageViewer* iv) :
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Transformation(img, iv)
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{
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}
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PNM* BinarizationNiblack::transform()
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{
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int width = image->width();
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int height = image->height();
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int r = getParameter("r").toInt();
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double a = getParameter("a").toDouble();
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double arithmetic_mean = 0;
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double variance = 0;
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double standard_deviation = 0;
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math::matrix<float> window;
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int T;
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PNM* newImage = new PNM(width, height, QImage::Format_Mono);
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for (int x=0; x < width; x++)
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{
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for (int y=0; y < height; y++)
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{
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// Get current pixel
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QRgb pixel = image->pixel(x, y);
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//Get current window
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window = getWindow(x, y, r, LChannel, RepeatEdge);
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// Calculate arithmetic mean
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arithmetic_mean = window.sum() / pow(r, 2);
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// Calculate standard_deviation
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for (int i = 0; i < r+1; i++){
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for (int j = 0; i < r+1; i++){
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variance += pow(window[i][j] - arithmetic_mean, 2);
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}
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}
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variance /= pow(r, 2);
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standard_deviation = sqrt(variance);
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// Calculate threshold T
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T = arithmetic_mean + a * standard_deviation;
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if(qGray(pixel) > T)
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{
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newImage->setPixel(x, y, Qt::color1);
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}
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else
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{
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newImage->setPixel(x, y, Qt::color0);
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}
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}
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}
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return newImage;
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}
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