Reduce the size of a bitmap to a specified size in Android

TharakaNirmana picture TharakaNirmana · Jun 6, 2013 · Viewed 43.3k times · Source

I want to reduce the size of a bitmap to 200kb exactly. I get an image from the sdcard, compress it and save it to the sdcard again with a different name into a different directory. Compression works fine (3 mb like image is compressed to around 100 kb). I wrote the following lines of codes for this:

String imagefile ="/sdcard/DCIM/100ANDRO/DSC_0530.jpg";
Bitmap bm = ShrinkBitmap(imagefile, 300, 300);

//this method compresses the image and saves into a location in sdcard
    Bitmap ShrinkBitmap(String file, int width, int height){

         BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
            bmpFactoryOptions.inJustDecodeBounds = true;
            Bitmap bitmap = BitmapFactory.decodeFile(file, bmpFactoryOptions);

            int heightRatio = (int)Math.ceil(bmpFactoryOptions.outHeight/(float)height);
            int widthRatio = (int)Math.ceil(bmpFactoryOptions.outWidth/(float)width);

            if (heightRatio > 1 || widthRatio > 1)
            {
             if (heightRatio > widthRatio)
             {
              bmpFactoryOptions.inSampleSize = heightRatio;
             } else {
              bmpFactoryOptions.inSampleSize = widthRatio; 
             }
            }

            bmpFactoryOptions.inJustDecodeBounds = false;
            bitmap = BitmapFactory.decodeFile(file, bmpFactoryOptions);

            ByteArrayOutputStream stream = new ByteArrayOutputStream();   
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);   
            byte[] imageInByte = stream.toByteArray(); 
            //this gives the size of the compressed image in kb
            long lengthbmp = imageInByte.length / 1024; 

            try {
                bitmap.compress(CompressFormat.JPEG, 100, new FileOutputStream("/sdcard/mediaAppPhotos/compressed_new.jpg"));
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }


         return bitmap;
        }

Answer

TharakaNirmana picture TharakaNirmana · Aug 5, 2014

I found an answer that works perfectly for me:

/**
 * reduces the size of the image
 * @param image
 * @param maxSize
 * @return
 */
public Bitmap getResizedBitmap(Bitmap image, int maxSize) {
    int width = image.getWidth();
    int height = image.getHeight();

    float bitmapRatio = (float)width / (float) height;
    if (bitmapRatio > 1) {
        width = maxSize;
        height = (int) (width / bitmapRatio);
    } else {
        height = maxSize;
        width = (int) (height * bitmapRatio);
    }
    return Bitmap.createScaledBitmap(image, width, height, true);
}

calling the method:

Bitmap converetdImage = getResizedBitmap(photo, 500);

Where photo is your bitmap