Hi,I am trying to do histogram equalization using opencv java, but i keep getting Assertion failed (_src.type() == CV_8UC1) anyone can help?

convertTo

asked 2016-01-01 01:39:05 -0600

Amer
6 ●1

updated 2016-01-01 16:43:17 -0600

this is my code

 Mat doraImage= Imgcodecs.imread("C:/test/dora.jpg" , Imgcodecs.CV_LOAD_IMAGE_COLOR);

if(doraImage.channels() == 3) {
        doraImage.convertTo(doraImage, Imgproc.COLOR_BGR2YCrCb);
  else if(doraImage.channels() == 4) {
       doraImage.convertTo(doraImage, Imgproc.COLOR_BGR2YCrCb);
    }
    Imgproc.equalizeHist(doraImage, doraImage);

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answered 2016-01-01 16:48:59 -0600

berak
32993 ●7 ●81 ●312

updated 2016-01-02 02:21:22 -0600

convertTo changes the depth(channel type), not the channel count, also, if you used Imgcodecs.CV_LOAD_IMAGE_COLOR for loading, you're safe to assume, the image is CV_8UC3, so you can skip the 4 channel case.

what you need instead is cvtColor(), like:

Mat gray = new Mat();
cvtColor(doraImage, gray, Imgproc.COLOR_BGR2YCrCb);
Imgproc.equalizeHist(gray, gray);
// process gray image
// then, 
gray.release();