compute Bitmap Sample Size by BitmapFactory.Options - Android Graphics

Android examples for Graphics:Bitmap Sample Size

  1. HOME
  2. Android
  3. Graphics
  4. Bitmap Sample Size

Description

compute Bitmap Sample Size by BitmapFactory.Options

Demo Code


//package com.java2s;
import android.graphics.BitmapFactory;

public class Main {
    public static int computeSampleSize(BitmapFactory.Options options,
            int minSideLength, int maxNumOfPixels) {
        int initialSize = computeInitialSampleSize(options, minSideLength,
                maxNumOfPixels);//w  w w .  jav  a2  s  . c o  m

        int roundedSize;
        if (initialSize <= 8) {
            roundedSize = 1;
            while (roundedSize < initialSize) {
                roundedSize <<= 1;
            }
        } else {
            roundedSize = (initialSize + 7) / 8 * 8;
        }

        return roundedSize;
    }

    private static int computeInitialSampleSize(
            BitmapFactory.Options options, int minSideLength,
            int maxNumOfPixels) {
        double w = options.outWidth;
        double h = options.outHeight;

        int lowerBound = (maxNumOfPixels == -1) ? 1 : (int) Math.ceil(Math
                .sqrt(w * h / maxNumOfPixels));
        int upperBound = (minSideLength == -1) ? 128 : (int) Math.min(
                Math.floor(w / minSideLength),
                Math.floor(h / minSideLength));

        if (upperBound < lowerBound) {
            // return the larger one when there is no overlapping zone.
            return lowerBound;
        }

        if ((maxNumOfPixels == -1) && (minSideLength == -1)) {
            return 1;

        } else if (minSideLength == -1) {
            return lowerBound;

        } else {
            return upperBound;
        }
    }
}

Related Tutorials