How to read the pixels of the three channels at the same time?

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asked Jun 27 '12

icedecker
613 ●6 ●9 ●19

updated Nov 30 '0

sturkmen

6772 ●3 ●48 ●79 https://github.com/stu...

Hi, I'm trying to convert the following C++ code in Java (for an Android app). I need to sum the pixels in the three channels at the same time (and others operations). Any suggestions?

vector<Mat> channel; // in java List<Mat> channel = null;
split(img, channel); // in java org.opencv.core.Core.split(img, channel);

// sum the pixels of three channels - How to do it in Java? The it_r, it_g and it_b are iterators
for (; it_r != it_endr; ++it_r, ++it_g, ++it_b) {
    r = (double) *it_r;
    g = (double) *it_g;
    b = (double) *it_b;

    tmp = r + g + b;
    if (tmp > sum) {
        sum = tmp;
    }
}

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answered Jun 28 '12

Andrey Pavlenko
1808 ●3 ●18 ●39

Mat mRgb = ...
List<Mat> lRgb = new ArrayList<Mat>(3);
Core.split(mRgb, lRgb);
Mat mR = lRgb.get(0);
Mat mG = lRgb.get(1);
Mat mB = lRgb.get(2);
Mat mSum = new Mat();
Mat mEmpty = new Mat();
Core.add(mR,   mG, mSum, mEmpty, CvType.CV_16UC1);
Core.add(mSum, mB, mSum, mEmpty, CvType.CV_16UC1);
double maxSum = Core.norm(mSum, Core.NORM_INF);

Comments

Thank you very much, it worked!

icedecker (Jun 28 '12)edit

why my Eclipse can't recognize the "CV_16UC1" ?

maizi (May 14 '14)edit

Hello Sir, I tried your code in my Android application in Java using openCv library, it did not work, I just wanted to split the colorful bitmap image into its three different rgb channel images. It will be so great if you could help me in this situation.