Haris Haris - 4 months ago 40
Android Question

Android byte array to Bitmap How to

How can I convert byte array received using socket.


  1. The C++ client send image data which is of type uchar.

  2. At the android side I am receiving this uchar array as byte[] which is ranges from -128 to +127.



What I wanted to do is that receives this data and display it. For that I was trying to convert to Bitmap using
BitmapFactory.decodeByteArray()
, but no luck I am getting null Bitmap. Am I doing right or any other method available.

Thanks in advance....

Jon Jon
Answer

I've been using it like below in one of my projects and so far it's been pretty solid. I'm not sure how picky it is as far as it not being compressed as a PNG though.

byte[] bytesImage;
Bitmap bmpOld;   // Contains original Bitmap
Bitmap bmpNew;

ByteArrayOutputStream baoStream = new ByteArrayOutputStream();
bmpOld.compress(Bitmap.CompressFormat.PNG, 100, baoStream);
bytesImage = baoStream.toByteArray();
bmpNew = BitmapFactory.decodeByteArray(bytesImage, 0, bytesImage.length);

edit: I've adapted the code from this post to use RGB, so the code below should work for you. I haven't had a chance to test it yet so it may need some adjusting.

Byte[] bytesImage = {0,1,2, 0,1,2, 0,1,2, 0,1,2};
int intByteCount = bytesImage.length;
int[] intColors = new int[intByteCount / 3];
int intWidth = 2;
int intHeight = 2;
final int intAlpha = 255;
if ((intByteCount / 3) != (intWidth * intHeight)) {
    throw new ArrayStoreException();
}
for (int intIndex = 0; intIndex < intByteCount - 2; intIndex = intIndex + 3) {
    intColors[intIndex / 3] = (intAlpha << 24) | (bytesImage[intIndex] << 16) | (bytesImage[intIndex + 1] << 8) | bytesImage[intIndex + 2];
}
Bitmap bmpImage = Bitmap.createBitmap(intColors, intWidth, intHeight, Bitmap.Config.ARGB_8888);
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