Decodes an image File to Bitmap resizing the image to be inSampleSize times smaller then the original. - Android Graphics

Android examples for Graphics:Bitmap File

  1. HOME
  2. Android
  3. Graphics
  4. Bitmap File

Description

Decodes an image File to Bitmap resizing the image to be inSampleSize times smaller then the original.

Demo Code

/*******************************************************************************
 * Copyright 2013 AppGlu, Inc.// w w w .j ava2 s.c  o  m
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
//package com.java2s;
import java.io.File;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

public class Main {
    /**
     * Decodes an image File to Bitmap resizing the image to be <code>inSampleSize</code> times smaller then the original.
     * @param file the image file reference
     * @param inSampleSize how much smaller that the image will be, for example, <code>inSampleSize</code> equals 2 will return an image 1/2 the size of the original
     * @return the resized Bitmap
     */
    public static Bitmap decodeSampledBitmapFromFile(File file,
            int inSampleSize) {
        BitmapFactory.Options options = new BitmapFactory.Options();

        options.inSampleSize = inSampleSize;

        return BitmapFactory.decodeFile(file.getPath(), options);
    }

    /**
     * Decodes an image File to Bitmap resizing the image to fit the <code>requestedWidth</code> and <code>requestedHeight</code> dimensions.
     * @param file the image file reference
     * @param requestedWidth the final image width will be close to the requestedWidth (value is in pixels)
     * @param requestedHeight the final image height will be close to the requestedHeight (value is in pixels)
     * @return the resized Bitmap
     */
    public static Bitmap decodeSampledBitmapFromFile(File file,
            int requestedWidth, int requestedHeight) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;

        BitmapFactory.decodeFile(file.getPath(), options);

        int inSampleSize = calculateSampleSize(options, requestedWidth,
                requestedHeight);

        return decodeSampledBitmapFromFile(file, inSampleSize);
    }

    /**
     * Giving a max width and height in pixels this method will calculate a good value to use in BitmapFactory.Options.inSampleSize.
     */
    public static int calculateSampleSize(BitmapFactory.Options options,
            int requestedWidth, int requestedHeight) {
        // Raw height and width of image
        int width = options.outWidth;
        int height = options.outHeight;
        int inSampleSize = 1;

        if (width > requestedWidth || height > requestedHeight) {
            // Calculate ratios of height and width to requested height and width
            final int widthRatio = Math.round((float) width
                    / (float) requestedWidth);
            final int heightRatio = Math.round((float) height
                    / (float) requestedHeight);

            // Choose the smallest ratio as inSampleSize value, this will guarantee
            // a final image with both dimensions larger than or equal to the
            // requested height and width.
            inSampleSize = heightRatio < widthRatio ? heightRatio
                    : widthRatio;
        }

        return inSampleSize;
    }
}

Related Tutorials