Android Bitmap Size Get computeSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels)

Description

compute Sample Size

Declaration

private static int computeSampleSize(BitmapFactory.Options options,
            int minSideLength, int maxNumOfPixels) 

Method Source Code

//package com.java2s;

import android.graphics.BitmapFactory;

public class Main {
    private static final int UNCONSTRAINED = -1;

    private static int computeSampleSize(BitmapFactory.Options options,
            int minSideLength, int maxNumOfPixels) {
        int initialSize = computeInitialSampleSize(options, minSideLength,
                maxNumOfPixels);//from   ww w .j a  v a2  s. c  om
        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 == UNCONSTRAINED) ? 1 : (int) Math
                .ceil(Math.sqrt(w * h / maxNumOfPixels));
        int upperBound = (minSideLength == UNCONSTRAINED) ? 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 == UNCONSTRAINED)
                && (minSideLength == UNCONSTRAINED)) {
            return 1;
        } else if (minSideLength == UNCONSTRAINED) {
            return lowerBound;
        } else {
            return upperBound;
        }
    }
}

Related

1. computeSampleSizeLarger(float scale)
2. getBitmapSize(Bitmap bitmap)
3. calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight)
4. calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight)
5. computeInitialSampleSize( BitmapFactory.Options options, int minSideLength, int maxNumOfPixels)
6. getBitmapSize(Bitmap bitmap)
7. getBitmapSize(String strImagePath)
8. getBitmapSize(String strImagePath, boolean checkOrientation)