Qt图像处理技术六:拉普拉斯锐化

Qt图像处理技术六:拉普拉斯锐化

效果图

源码

由该公式得到下方卷积核

使用到的卷积核:

//都把QImage转化为rgb888更好运算
QImage LaplaceSharpen(const QImage &origin)
{
    QImage imgCopy;
    int width = img.width();
    int height = img.height();
    int window[3][3] = {0, -1, 0, -1, 4, -1, 0, -1, 0};
    if (img.format() != QImage::Format_RGB888) {
        imgCopy = QImage(width, height, QImage::Format_RGB888);
    } else {
        imgCopy = QImage(img);
    }
    QImage imgCopyrgbImg = QImage(img).convertToFormat(QImage::Format_RGB888);
    uint8_t *rgbImg = imgCopyrgbImg.bits();
    uint8_t *rgb = imgCopy.bits();

    int nRowBytes = (width * 24 + 31) / 32 * 4;
    int  lineNum_24 = 0;
    for (int x = 1; x < img.width(); x++) {
        for (int y = 1; y < img.height(); y++) {
            int sumR = 0;
            int sumG = 0;
            int sumB = 0;

            for (int m = x - 1; m <= x + 1; m++)
                for (int n = y - 1; n <= y + 1; n++) {
                    if (m >= 0 && m < width && n < height) {
                        lineNum_24 = n * nRowBytes;
                        sumR += rgbImg[lineNum_24 + m * 3] * window[n - y + 1][m - x + 1];
                        sumG += rgbImg[lineNum_24 + m * 3 + 1] * window[n - y + 1][m - x + 1];
                        sumB += rgbImg[lineNum_24 + m * 3 + 2] * window[n - y + 1][m - x + 1];
                    }
                }

            int old_r = rgbImg[lineNum_24 + x * 3];
            sumR += old_r;
            sumR = qBound(0, sumR, 255);

            int old_g = rgbImg[lineNum_24 + x * 3 + 1];
            sumG += old_g;
            sumG = qBound(0, sumG, 255);

            int old_b = rgbImg[lineNum_24 + x * 3 + 2];
            sumB += old_b;
            sumB = qBound(0, sumB, 255);
            lineNum_24 = y * nRowBytes;
            rgb[lineNum_24 + x * 3] = sumR;
            rgb[lineNum_24 + x * 3 + 1] = sumG;
            rgb[lineNum_24 + x * 3 + 2] = sumB;
        }
    }

    return imgCopy;
}