C ++按像素創建和保存OpenCV 16位圖像

Question

我想通過手動設置像素值以產生噪聲，用OpenCV創建一個16位的PNG圖像。 我嘗試了以下方法：

cv::Mat img16(WINDOW_Y, WINDOW_X, CV_16UC3); // create 16 bit mat

float val, new_value;
float noise = 3.1343; // actually randomly generated by randomizer in (0..255)
for (int x = 0; x < WINDOW_X; x++) {
    for (int y = 0; y < WINDOW_Y; y++) {
        for (int i = 0; i < 3; i++) {
            // get value from another CV_8UC3-mat
            val = img.at<cv::Vec3b>(y,x)[i]; 
            // add up noise and scale to 16bit
            new_value = (val + noise)*255; 
            // avoid overflow at 2^16-1
            if (new_value > 65535) { 
                new_value = 65535;
            }
            // set the value to 16bit mat
            img16.at<cv::Vec3s>(y,x)[i] = (short) new_value;
        }
    }
}
// write to PNG file, since PNG supports 16 bit
cv::imwrite(file + ".png", img16);

我得到的輸出似乎是16位：

 $ identify output.png 
 output.png PNG 128x128 128x128+0+0 16-bit PseudoClass 65536c

但是它顯示出單調灰色（＃808080），而我希望圖像是異類的。 它出什么問題了？

Answer 1

每當您發現自己在opencv中編寫每個像素的循環時，請-堅持嘗試並嘗試找到內置的內容。

Mat ocv=Mat(200,200,CV_16UC3); // as you can only save 16bit *unsigned* as png or tif
theRNG().fill(ocv,RNG::UNIFORM,0,65535);