在Android中按比例缩小图片

Question

I am implementing an application in which an activity shows a image view with full screen. Now i have some images downloaded in application's file directory. I want to set image to image view in that activity for which i am scaling down the larger images. I am getting OutOfMemory error after 10 to 15 mins of using application. error is in decodeFile of BitmapFactory. Here is my code :

public static int calculateInSampleSize(
        BitmapFactory.Options options, int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {
        if (width > height) {
            inSampleSize = Math.round((float)height / (float)reqHeight);
        } else {
            inSampleSize = Math.round((float)width / (float)reqWidth);
        }
    }
    return inSampleSize;
}

public static Bitmap decodeSampledBitmapFromFile(String imagePath,
        int reqWidth, int reqHeight) {

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(imagePath, options);

    // Calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    return BitmapFactory.decodeFile(imagePath, options);

}

Right now i am giving reqHeight = 500 and reqWidth = 500

This code is given in Android guidelines page. Is there anything i am missing, if so please help me out. I tried lots of things but not getting any solution.

Answer 1

Change you int inSampleSize = 1; to int inSampleSize = 2 or 3 and test the application again, I hope this will solve your problem. I also suggest insted of this technique,try lazy loading for all you image dowanload by doing so there will be no bitmap and outOfMemoryError. Yo can have lazy loading - https://github.com/thest1/LazyList

Answer 2

Try using this

Bitmap resizedbitmap2 = Bitmap.createScaledBitmap(your_bitmap, width, height,
                        true);

it will help you.

Answer 3

There might be a memory leak in your app if you are storing list of bitmaps returned by decodeSampledBitmapFromFile somewhere. Try to check for memory leak and also use Bitmap.recycle() to recycle bitmaps and help android free memory.