Android Bitmap Size Get computeInitialSampleSize(int w, int h, int minSideLength, int maxNumOfPixels)

Description

compute Initial Sample Size

Declaration

private static int computeInitialSampleSize(int w, int h,
            int minSideLength, int maxNumOfPixels) 

Method Source Code

//package com.java2s;

import android.graphics.BitmapFactory;

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

    private static int computeInitialSampleSize(int w, int h,
            int minSideLength, int maxNumOfPixels) {
        if (maxNumOfPixels == UNCONSTRAINED
                && minSideLength == UNCONSTRAINED)
            return 1;

        int lowerBound = (maxNumOfPixels == UNCONSTRAINED) ? 1 : (int) Math
                .ceil(Math.sqrt((double) (w * h) / maxNumOfPixels));

        if (minSideLength == UNCONSTRAINED) {
            return lowerBound;
        } else {//w  w w  .  j  a va  2s .c o m
            int sampleSize = Math.min(w / minSideLength, h / minSideLength);
            return Math.max(sampleSize, lowerBound);
        }
    }

    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. getImageWH(String path)
2. inSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight)
3. obtainBitmapSize(String pathName)
4. computeSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels)
5. computeInitialSampleSize( BitmapFactory.Options options, int minSideLength, int maxNumOfPixels)
6. computeInitialSampleSize( BitmapFactory.Options options, int minSideLength, int maxNumOfPixels)
7. computeInSampleSizeForMoment(Bitmap map, int newWidth, int newHeight)
8. computeSampleSize(int width, int height, int minSideLength, int maxNumOfPixels)
9. computeSampleSize(float scale)