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[TASK] Implement basic yuv handling.

This commit is contained in:
Jan Philipp Timme 2015-12-11 13:44:32 +01:00
parent 6514501d1a
commit b762a3a076
2 changed files with 60 additions and 6 deletions
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17
imageviewer-qt4.cpp
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@ -235,11 +235,16 @@ void ImageViewer::adjustBrightness(int b) {
for(int x=0; x<working_copy->getImage()->width(); x++) { for(int x=0; x<working_copy->getImage()->width(); x++) {
for(int y=0; y<working_copy->getImage()->height(); y++) { for(int y=0; y<working_copy->getImage()->height(); y++) {
QColor color = QColor::fromRgb(original->getImage()->pixel(x, y)); QColor color = QColor::fromRgb(original->getImage()->pixel(x, y));
color.getHsl(&h, &s, &old_l); // color.getHsl(&h, &s, &old_l);
new_l = old_l + delta; // new_l = old_l + delta;
if(new_l > 255) new_l = 255; // if(new_l > 255) new_l = 255;
if(new_l < 0) new_l = 0; // if(new_l < 0) new_l = 0;
color.setHsl(h, s, new_l); // color.setHsl(h, s, new_l);
struct yuv yuv = LazyImage::RGBToYUV(color.rgb());
yuv.y = yuv.y + (delta / 255.0);
if(yuv.y > 1) yuv.y = 1;
if(yuv.y < 0) yuv.y = 0;
color = LazyImage::YUVToRGB(yuv);
working_copy->getImage()->setPixel(x, y, color.rgb()); working_copy->getImage()->setPixel(x, y, color.rgb());
} }
} }
@ -564,7 +569,7 @@ void ImageViewer::applyBasicFilter() {
*/ */
void ImageViewer::applyBasicFilterWithOverflowHandling() { void ImageViewer::applyBasicFilterWithOverflowHandling() {
QString chosen_mode = filter_mode_combobox->currentText(); QString chosen_mode = filter_mode_combobox->currentText();
LazyImage::overflowMode overflow_mode; LazyImage::overflowMode overflow_mode = LazyImage::CONSTANT; // default for compiler
if(chosen_mode == "Zero padding") overflow_mode = LazyImage::ZERO_PADDING; if(chosen_mode == "Zero padding") overflow_mode = LazyImage::ZERO_PADDING;
else if(chosen_mode == "Constant") overflow_mode = LazyImage::CONSTANT; else if(chosen_mode == "Constant") overflow_mode = LazyImage::CONSTANT;
else if(chosen_mode == "Continuous") overflow_mode = LazyImage::CONTINUOUS; else if(chosen_mode == "Continuous") overflow_mode = LazyImage::CONTINUOUS;

49
lazy_image.cpp
View File

@ -9,6 +9,13 @@
#include <math.h> #include <math.h>
struct yuv {
// values in [0,1]
double y; // brightness
double u; // red/green part
double v; // green/blue part
};
class LazyImage { class LazyImage {
private: private:
@ -255,6 +262,48 @@ class LazyImage {
return this->img->pixel(x, y); return this->img->pixel(x, y);
} }
}; };
static struct yuv RGBToYUV(QColor input) {
struct yuv result;
int input_r, input_g, input_b;
input.getRgb(&input_r, &input_g, &input_b);
//std::cout << input_r << "," << input_g << "," << input_b << " (rgb) -> (yuv) ";
// normalize input rgb to values in [0,1]
double r, g, b;
r = input_r / 255.0;
g = input_g / 255.0;
b = input_b / 255.0;
// calculate yuv
result.y = 0.299 * r + 0.587 * g + 0.114 * b;
result.u = (b - result.y) * 0.493;
result.v = (r - result.y) * 0.877;
//std::cout << result.y << "," << result.u << "," << result.v << std::endl;
return result;
};
static QColor YUVToRGB(struct yuv input) {
double r, g, b;
// calculate rgb
//std::cout << input.y << "," << input.u << "," << input.v << " (yuv) -> (rgb) ";
b = (input.u / 0.493) + input.y;
r = (input.v / 0.877) + input.y;
// möp g = (input.y - 0.299*r - 0.144*b) / 0.587;
g = (1.0/0.587)*input.y - (0.299/0.587)*r - (0.114/0.585)*b;
// normalize into [0,255]
int output_r, output_g, output_b;
output_r = qRound(r * 255.0);
output_g = qRound(g * 255.0);
output_b = qRound(b * 255.0);
if(output_r < 0) output_r = 0;
if(output_g < 0) output_g = 0;
if(output_b < 0) output_b = 0;
if(output_r > 255) output_r = 255;
if(output_g > 255) output_g = 255;
if(output_b > 255) output_b = 255;
//std::cout << output_r << "," << output_g << "," << output_b << std::endl << std::endl;
QColor result = QColor(output_r, output_g, output_b);
return result;
};
}; };