Question

I’ve created small app that works with images from gallery or camera.

It all works fine, but.
On device with small screen and small memory size (HTC Desire) I have some images downloaded in full size from other mobile phone, and they are much larger (8MP camera on that phone).

If I try to load that, for my small camera huge image, it will crash immediately.

So, how to implement some kind of check and to downsize that image, but still load it properly?

I do scale images down after they are loaded, but this is something that should be done before the crash appears.

Tnx.

           InputStream in = null;
            try {
                in = getContentResolver().openInputStream(data.getData());
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            // get picture size.
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(in, null, options);
            try {
                in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            // resize the picture for memory.
            int screenH = getResources().getDisplayMetrics().heightPixels; //800
            int screenW = getResources().getDisplayMetrics().widthPixels; //480
            int width = options.outWidth / screenW;
            int height = options.outHeight / screenH;

            Log.w("Screen Width", Integer.toString(width));
            Log.w("Screen Height", Integer.toString(height));

            int sampleSize = Math.max(width, height);
            options.inSampleSize = sampleSize;
            options.inJustDecodeBounds = false;
            try {
                in = getContentResolver().openInputStream(data.getData());
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            // convert to bitmap with declared size.
            Globals.INSTANCE.imageBmp = BitmapFactory.decodeStream(in, null, options);
            try {
                in.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

Answer 1

you can avoid load the bitmap in memory just setting

inJustDecodeBounds = true

inJustDecodeBounds will allow you to decode only the bounds of the image without decode it. Given height and width of your bitmap you can downsampling it using.

inSampleSize

as the doc stays:

If set to a value > 1, requests the decoder to subsample the original
image, returning a smaller image to save memory.

int tmpWidth = bitmapWidth;
int tmpHeight = bitmapHeigth;
int requiredSize = ...
while (true) {
 if (tmpWidth / 2 < requiredSize
    || tmpHeight / 2 < requiredSize)
        break;
    tmpWidth /= 2;
    tmpHeight /= 2;
    ratio *= 2;
 }

EDIT: for a 32 bit Bitmap the memory required is width * height * 4