How to pixelize a bitmap in android

Question

I have been searching but i did not find a question about how to pixelize a bitmap in android

Example

Note that i dont mean blur

Please improve your googling skills: http://www.41post.com/4241/programming/android-disabling-anti-aliasing-for-pixel-art — Phantômaxx, Aug 10 '15 at 08:13

score 6 · Accepted Answer · edited May 23 '17 at 12:29

You could just try and resize that image to a smaller version (and then back up if you need it at the same size as the original for some reason)

{
    Bitmap original = ...;
    //Calculate proportional size, or make the method accept just a factor of scale.
    Bitmap small = getResigetResizedBitmap(original, smallWidth, smallHeight);
    Bitmap pixelated = getResigetResizedBitmap(small, normalWidth, normalHeight);
   //Recycle small, recycle original if no longer needed.
}

public Bitmap getResizedBitmap(Bitmap bm, int newWidth, int newHeight) {
    int width = bm.getWidth();
    int height = bm.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    // CREATE A MATRIX FOR THE MANIPULATION
    Matrix matrix = new Matrix();
    // RESIZE THE BIT MAP
    matrix.postScale(scaleWidth, scaleHeight);

    // "RECREATE" THE NEW BITMAP
    Bitmap resizedBitmap = Bitmap.createBitmap(
        bm, 0, 0, width, height, matrix, false);
    return resizedBitmap;
}

The code is from here

The trick is in setting the anti-aliasing boolean to **false**. — Phantômaxx, Aug 10 '15 at 08:29

score 0 · Answer 2 · answered Aug 10 '15 at 08:21

The simplest way to pixelate the image would be to scale image down using "nearest neighbour" algorithm, and then scale up, using the same algorithm.

Filtering over the image trying to find an average takes much more time, but does not actually give any improvements in result quality, after all you do intentionally want your image distorted.

How to pixelize a bitmap in android

2 Answers2