After some trial: first I try using the image as resource drawable and it still happen (transparent part of the image become black), secondly I convert the image to png image and it is work, so the problem is in the file type (gif). since in my real app the image obtained from server and I can't request image as always in png format, I use the solution from this link: Transparent GIF in Android ImageView
it is simple for displaying only one image (like in my question) since I use Picasso I use target to erase black color from image avatar like this:
target = new Target() {
@Override
public void onPrepareLoad(Drawable arg0) {
}
@Override
public void onBitmapLoaded(Bitmap bitmap, LoadedFrom arg1) {
if (Build.VERSION.SDK_INT == 19/*Build.VERSION_CODES.KITKAT*/){
Bitmap editedavatar = AndroidUtils.eraseColor(bitmap, -16777216);
avatar.setImageBitmap(editedavatar);
}
}
@Override
public void onBitmapFailed(Drawable arg0) {
avatar.setImageResource(R.drawable.ic_profile_default);
where erase color is static method
public static Bitmap eraseColor(Bitmap src, int color) {
int width = src.getWidth();
int height = src.getHeight();
Bitmap b = src.copy(Config.ARGB_8888, true);
b.setHasAlpha(true);
int[] pixels = new int[width * height];
src.getPixels(pixels, 0, width, 0, 0, width, height);
for (int i = 0; i < width * height; i++) {
if (pixels[i] == color) {
pixels[i] = 0;
}
}
b.setPixels(pixels, 0, width, 0, 0, width, height);
return b;
}
but since I use Picasso for displaying images in a listview,I impelements Target in ViewHolder and it is work very well so far.