Mat.createBuffer.get() returns data inconsistent with Mat.row().col().data.get()

[iis-MarkKuang]

original code

// 1. download image
String url = "https://www.google.com.hk/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png"
byte[] bytes = HttpUtils.downloadBytes(url); // simply downloads the image to bytes

// 2. parse the byte array to Bytedeco opencv mat
Mat mat = new Mat(bytes);

// 3. define normalize function
public Mat normalize(Mat mat) {
  Mat cloneMat = null;
  try (Size size = new Size(IMAGE_CONFIG.pHashImgWidth, IMAGE_CONFIG.pHashImgHeight);
       Rect rect = new Rect(0, 0, IMAGE_CONFIG.pHashDimSize, IMAGE_CONFIG.pHashDimSize)) {
    resize(mat, mat, size);

    cloneMat = mat.clone();
    cloneMat.convertTo(mat, CV_32FC1);
    dct(mat, mat);
    cloneMat.release();
    cloneMat.close();
    return new Mat(mat, rect);
  }
}

// 4. Normalize
mat = normalize(imdecode(mat, opencv_imgcodecs.IMREAD_GRAYSCALE));


// 5. get mat data to buffer, then to array
float[] data = new float[(int)mat.total() * mat.channels()];
FloatBuffer buffer = mat.createBuffer();
buffer.get(data);

// 6. Compare buffer data with Mat data, the first row is consistent, but the rest is not;
for (int i = 0; i < rows; i++) {
  for (int j = 0; j < cols; j++) {
    System.out.println(data[i * cols + j] + " " + mat.row(i).col(j).data().getFloat());
  }
}

// output
// First row, consistent
// 4231.4995 4231.4995
// 10.374468 10.374468
// -258.0788 -258.0788
// 130.85948 130.85948
// 130.10544 130.10544
// -110.18334 -110.18334
// -133.00644 -133.00644
// 76.05422 76.05422

// Second row onwards, inconsistent
// 52.51634 8.2322445
// -46.74162 42.705864
// -6.3990197 -45.12134
// -13.678903 32.170387
// -15.738309 -25.068441
// 26.591276 -4.0662885
// -15.69106 29.847733
// -45.807583 -18.502712
// 24.062498 22.55215
// 30.870342 0.975155
// -26.865278 212.19658
// -13.313238 -140.92426
// 9.827322 -144.26242
// 5.082619 98.95524
// -2.573051 130.77933
// 6.37136 -64.56056
// -14.64978 -2.9284372
// -11.879759 15.052319

Please help check.

[iis-MarkKuang]

Hi, can I get some priority on this matter? It's been a blocker.

[saudet]

Try to use createIndexer() instead: http://bytedeco.org/news/2014/12/23/third-release/