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I am scaling down an image taken by MediaStore.ACTION_IMAGE_CAPTURE (Tried to follow all the better practices)

Scaling the image is done in two steps:

  1. Decode the perfect sample of the captured image to Bitmap.
  2. Rotate and Scale the bitmap to fit into my device display size.

I don't really understand why sometimes image is perfectly displayed in the image view and sometimes its just blank! Any help is highly appreciated :-)

UPDATE: I am doing all the processing work in onActivityResult. Not sure its the reason behind this weird behavior?

For better understanding of the problem i am sharing some of the key sections of code:

Bitmap Factory Options 

BitmapFactory.Options options = new BitmapFactory.Options();
options.inDither = false;
options.inPurgeable = true;
options.inInputShareable = true;
options.inJustDecodeBounds = false;
options.inTempStorage = new byte[32 * 1024];
options.inSampleSize = calculateInSampleSize(imageHeight, imageWidth, screenHeight, screenWidth);

Sample Size calculation

private int calculateInSampleSize(int imageHeight, int imageWidth, int reqHeight, int reqWidth)
{
    int inSampleSize = 1;
    if (imageHeight > reqHeight || imageWidth > reqWidth) {

        final int halfHeight = imageHeight / 2;
        final int halfWidth = imageWidth / 2;

        while ((halfHeight / inSampleSize) > reqHeight
                && (halfWidth / inSampleSize) > reqWidth) {
            inSampleSize *= 2;
        }
    }
    return inSampleSize;
}

Decode and Re-sizing the Bitmap

image = BitmapFactory.decodeFile(fileName, options);
Matrix matrix = new Matrix();

float scaleFactor = Math.min(1.0f, Math.max(width / imageWidth, height / imageHeight));
matrix.postScale(scaleFactor, scaleFactor);

Bitmap tempImage = Bitmap.createBitmap(image, 0, 0, image.getWidth(), image.getHeight(), matrix, false);
if( image.isMutable() || (image.getHeight()!=tempImage.getHeight() || image.getWidth()!=tempImage.getWidth()) ) {
    image.recycle();
}

imageView.setImageBitmap(tempImage);
Obaida.Opu
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1 Answers1

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I figured it out finally and the problem was that the entire layout is being redrawn in the onResume() and so was ImageView was reset. I called the same method where I was setting this bitmap to imageview in the onResume() instead of onActivityResult() method and was finally able to get it to work.

LoveMeSomeFood
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  • Can you please explain further about whats going on? Previously i wasn't doing anything in the `onResume()` method. I have tried updating the image view image in the onResume method. But this doesn't seem to work for me. – Obaida.Opu Oct 25 '15 at 07:31
  • Are you saving the file's uri in onSaveInstanceState() and using it again in onRestoreInstanceState()? WHat I'm basically doing is, getting the bitmap using the file uri which I have saved in onSaveInstanceState() and setting it to the imageview. This solved the issue I had. – LoveMeSomeFood Nov 06 '15 at 21:14