filter.cpp

#include <QObject>
#include <QDebug>
#include <QColor>
#include <QImage>
#include <QQuickImageProvider>
#include <QElapsedTimer>
#include <vector>

#include "Filter.h"

Filter::Filter(QObject *parent) : QObject(parent), QQuickImageProvider(QQuickImageProvider::Image)
{
    this->_kernelRadius = 0;
}

Filter::~Filter(){
}

//
void Filter::setKernelRadius(int radius)
{
    qDebug() << "setKernelRadius:" << radius;
    this->_kernelRadius = radius;
}

//
QImage Filter::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
{
    QElapsedTimer et;

    QImage srcImage;
    QImage dstImage(requestedSize, QImage::Format::Format_RGBA8888);
    
    QString path = QStringLiteral(":/Parrots.png");
    srcImage.load(path);


    int width = requestedSize.width();
    int height = requestedSize.height();

    // コンボリューションカーネルの作成
    int kernelRadius = this->_kernelRadius;
    int kernelSize = 2*kernelRadius + 1;
    std::vector<std::vector<int>> kernel;
    kernel.resize(kernelSize);
    for (int y=0; y<kernelSize; y++) {
        kernel[y].resize(kernelSize);
        QString s = "";
        for (int x=0; x<kernelSize; x++) {
            int xx = x - kernelRadius;
            int yy = y - kernelRadius;
            if (sqrt(xx*xx + yy*yy) <= kernelRadius) {
                kernel[y][x] = 1.0f;
                s += "■" ;
            } else {
                kernel[y][x] = 0.0f;
                s += "□" ;
            }
        }
        qDebug() << s ;
    }

    et.start();

    // フィルター処理
    for (int y = 0; y < height; ++y)
    {
        for (int x = 0; x < width; ++x)
        {
            int r=0.0f,g=0.0f,b=0.0f;
            int count = 0;
            for (int ky=0; ky<kernelSize; ky++) {
                for (int kx=0; kx<kernelSize; kx++) {
                  int xx = x + kx - kernelSize/2;
                  int yy = y + ky - kernelSize/2;
                  if (srcImage.valid(xx, yy)) {
                      QColor color = srcImage.pixelColor(xx, yy);
                       int kv = kernel[ky][kx];
                      r += color.red() * kv;
                      g += color.green() * kv;
                      b += color.blue() * kv;
                      count += kv;
                  }
                }
            }

            QColor color(r/count, g/count, b/count);
            dstImage.setPixelColor(x, y, color);

        }
    }

    // 処理時間をコンソールに出力
    qDebug() << "elapsed time: " << QString::number(et.elapsed()) ;

    return dstImage;
}