histogram refactor + fixes

This commit is contained in:
Damian Kowalski 2024-04-07 12:07:24 +02:00
parent 718517590b
commit 664d4e19f9
3 changed files with 69 additions and 37 deletions

View File

@ -23,26 +23,14 @@ Histogram::~Histogram()
} }
void Histogram::generate(QImage* image) { void Histogram::generate(QImage* image) {
R->clear(); for (int x = 0; x < image->width(); ++x) {
G->clear(); for (int y = 0; y < image->height(); ++y) {
B->clear(); QRgb p = image->pixel(x, y);
L->clear();
if (image == nullptr) { Histogram::R->insert(qRed(p), Histogram::R->value(qRed(p)) + 1);
qDebug() << "Invalid image provided."; Histogram::G->insert(qGreen(p), Histogram::G->value(qGreen(p)) + 1);
return; Histogram::B->insert(qBlue(p), Histogram::B->value(qBlue(p)) + 1);
} Histogram::L->insert(qGray(p), Histogram::L->value(qGray(p)) + 1);
for (int y = 0; y < image->height(); ++y) {
for (int x = 0; x < image->width(); ++x) {
QColor pixelColor = image->pixelColor(x, y);
R->insert(pixelColor.red(), R->value(pixelColor.red()) + 1);
G->insert(pixelColor.green(), G->value(pixelColor.green()) + 1);
B->insert(pixelColor.blue(), B->value(pixelColor.blue()) + 1);
int luminance = qRound(0.299 * pixelColor.red() + 0.587 * pixelColor.green() + 0.114 * pixelColor.blue());
L->insert(luminance, L->value(luminance) + 1);
} }
} }
} }
@ -51,27 +39,37 @@ int Histogram::maximumValue(Channel selectedChannel)
{ {
int maxVal = 0; int maxVal = 0;
if (selectedChannel == RGB) { if(Histogram::getMaxChannel(R) > maxVal) {
int maxR = maximumValue(RChannel); maxVal = Histogram::getMaxChannel(R);
int maxG = maximumValue(GChannel);
int maxB = maximumValue(BChannel);
maxVal = std::max(maxR, std::max(maxG, maxB));
} }
else {
QHash<int, int>* hist = get(selectedChannel);
QHash<int, int>::const_iterator cit = hist->constBegin(); if(Histogram::getMaxChannel(G) > maxVal) {
while (cit != hist->constEnd()) { maxVal = Histogram::getMaxChannel(G);
if (cit.value() > maxVal) { }
maxVal = cit.value();
} if(Histogram::getMaxChannel(B) > maxVal) {
++cit; maxVal = Histogram::getMaxChannel(B);
} }
if(Histogram::getMaxChannel(L) > maxVal) {
maxVal = Histogram::getMaxChannel(L);
} }
return maxVal; return maxVal;
} }
int Histogram::getMaxChannel(QHash<int, int>* channel) {
int maxValue = 0;
for(int i = 0; i < channel->size(); i++)
{
if(channel->value(i) > maxValue)
maxValue = channel->value(i);
}
return maxValue;
}
QHash<int, int>* Histogram::get(Channel channel = LChannel) QHash<int, int>* Histogram::get(Channel channel = LChannel)
{ {
if (channel==LChannel) return L; if (channel==LChannel) return L;
@ -91,7 +89,7 @@ QImage Histogram::getImage(Channel channel = LChannel, QBrush pen = Qt::gray)
QImage histImage(255, 100, QImage::Format_ARGB32); QImage histImage(255, 100, QImage::Format_ARGB32);
histImage.fill(0); histImage.fill(0);
QPainter painter(&histImage); QPainter painter(&histImage);
painter.setBrush(Qt::transparent); painter.setBrush(Qt::transparent);
painter.setPen(Qt::transparent); painter.setPen(Qt::transparent);
painter.drawRect(0,0,255,100); painter.drawRect(0,0,255,100);

View File

@ -19,6 +19,7 @@ public:
private: private:
void generate(QImage*); // iterates all parent image pixels and set the Hashes void generate(QImage*); // iterates all parent image pixels and set the Hashes
int getMaxChannel(QHash<int, int>*);
QHash<int, int>* R; QHash<int, int>* R;
QHash<int, int>* G; QHash<int, int>* G;

View File

@ -1,6 +1,6 @@
#include "histogram_equalization.h" #include "histogram_equalization.h"
#include "../histogram.h" #include "../histogram.h"
#include <cmath> // Dla funkcji round
HistogramEqualization::HistogramEqualization(PNM* img) : HistogramEqualization::HistogramEqualization(PNM* img) :
Transformation(img) Transformation(img)
@ -17,10 +17,43 @@ PNM* HistogramEqualization::transform()
int width = image->width(); int width = image->width();
int height = image->height(); int height = image->height();
// Tworzymy nowy obiekt PNM do przechowywania przetworzonego obrazu
PNM* newImage = new PNM(width, height, image->format()); PNM* newImage = new PNM(width, height, image->format());
qDebug() << Q_FUNC_INFO << "Not implemented yet!"; // Tworzymy histogram dla obecnego obrazu
Histogram* hist = image->getHistogram(); // Nie przekazujemy argumentów
// Pobieramy łączną liczbę pikseli na obrazie
int totalPixels = width * height;
// Tworzymy dystrybuantę
QVector<double> cdf(256, 0.0); // Inicjalizujemy wszystkie wartości na 0.0
double sum = 0.0;
for (int i = 0; i < 256; ++i) {
sum += hist->get(Histogram::LChannel)->value(i) / static_cast<double>(totalPixels); // Używamy kanału luminancji
cdf[i] = sum;
}
// Normalizujemy dystrybuantę do przedziału [0, 255]
QVector<int> lookupTable(256, 0);
for (int i = 0; i < 256; ++i) {
lookupTable[i] = round(cdf[i] * 255);
}
// Przeprowadzamy wyrównywanie histogramu
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
QRgb pixel = image->pixel(x, y);
int grayValue = qGray(pixel); // Pobieramy wartość odcienia szarości
// Używamy wartości z lookupTable jako nowej wartości odcienia szarości
int newGrayValue = lookupTable[grayValue];
QRgb newPixel = qRgb(newGrayValue, newGrayValue, newGrayValue); // Ustawiamy nową wartość dla każdego kanału RGB
// Ustawiamy nowy piksel na obrazie docelowym
newImage->setPixel(x, y, newPixel);
}
}
return newImage; return newImage;
} }