CODEWITHSUNDEEP
androidopencv
Piyush
Piyush

Reputation: 626

Convert image in Mat object to a Float Array in Android

I am reading an image in Android and I want to access the pixel values of the image.

I am reading the images like this

Mat img1 = new Mat();
img1 = Highgui.imread(filePath1);

Is there an efficient way to convert the Mat object to a float array?

Currently, I am doing it like this & this is very slow.

private float[][] convertToFloatArray(String filePath1){

    img1 = Highgui.imread(filePath1);
    String output = img1.dump();
    float[][] flt = new float[img1.rows()][img1.cols()];

    // slowest step but necessary to remove [, ;, etc.
    String array1[] = output.split("[^0-9]+"); 

    int k = 0;
    for(int i = 0;i<img1.rows();i++) {
        for(int j = 0;j<img1.cols();j++) {
            flt[i][j] = (Float.valueOf(array1[k])).floatValue();
            k += 1;
        }
    }

Upvotes: 1

Views: 2665

Answers (2)

Piyush
Piyush

Reputation: 626

Was able to figure out a solution

        img1 = new Mat();
        img1 = Highgui.imread(filePath1, 0);
        int buff[] = new int[(int)img1.total() * img1.channels()];
        img1.get(0, 0, buff);
        return buff;

Upvotes: 1

jester
jester

Reputation: 238

You mentioned int array would be fine. You can skip the string float and string lines you are using above and just use this:

  int k = 0;
    for(int i = 0;i<img1.rows();i++) {
        for(int j = 0;j<img1.cols();j++) {
            int_arr[i][j] = static_cast<unsigned>(img1.data[k]);
            k += 1;
        }
    }

Also keep track of how many channels you have.

Upvotes: 0

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