Android Bitmap Scale scaleImg(Bitmap bitmap, float scale)

Description

scale Img

License

Apache License

Declaration

public static Bitmap scaleImg(Bitmap bitmap, float scale) 

Method Source Code

/*/*from   ww  w  .  j  a v a 2  s.co  m*/
 * Copyright (C) 2013 www.418log.org
 * 
 * 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:
 *
 * 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.
 */

import java.io.File;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Matrix;

public class Main {

    public static Bitmap scaleImg(File file, int newWidth, int newHeight) {
        Bitmap resizeBmp = null;
        if (newWidth <= 0 || newHeight <= 0) {
            throw new IllegalArgumentException(
                    "???????????????0");
        }
        BitmapFactory.Options opts = new BitmapFactory.Options();
        
        opts.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(file.getPath(), opts);
        
        
        
        int srcWidth = opts.outWidth;
        int srcHeight = opts.outHeight;

        int destWidth = srcWidth;
        int destHeight = srcHeight;

        
        float scale = 0;
        
        float scaleWidth = (float) newWidth / srcWidth;
        float scaleHeight = (float) newHeight / srcHeight;
        if (scaleWidth > scaleHeight) {
            scale = scaleWidth;
        } else {
            scale = scaleHeight;
        }
        if (scale != 0) {
            destWidth = (int) (destWidth / scale);
            destHeight = (int) (destHeight / scale);
        }

        
        opts.inPreferredConfig = Bitmap.Config.RGB_565;
        
        
        opts.inPurgeable = true;
        
        opts.inInputShareable = true;

        
        if (scale > 1) {
            
            opts.inSampleSize = (int) scale;
        } else {
            
            opts.inSampleSize = 1;
        }

        
        opts.outHeight = destHeight;
        opts.outWidth = destWidth;
        
        opts.inJustDecodeBounds = false;
        
        opts.inDither = false;
        
        resizeBmp = BitmapFactory.decodeFile(file.getPath(), opts);
        
        if (resizeBmp != null && scale != 1) {
            resizeBmp = scaleImg(resizeBmp, scale);
        }
        
        return resizeBmp;
    }

    public static Bitmap scaleImg(Bitmap bitmap, int newWidth, int newHeight) {

        Bitmap resizeBmp = null;
        if (bitmap == null) {
            return null;
        }
        if (newWidth <= 0 || newHeight <= 0) {
            throw new IllegalArgumentException(
                    "???????????????0");
        }
        
        int srcWidth = bitmap.getWidth();
        int srcHeight = bitmap.getHeight();

        if (srcWidth <= 0 || srcHeight <= 0) {
            return null;
        }
        
        float scale = 0;
        
        float scaleWidth = (float) newWidth / srcWidth;
        float scaleHeight = (float) newHeight / srcHeight;
        if (scaleWidth > scaleHeight) {
            scale = scaleWidth;
        } else {
            scale = scaleHeight;
        }
        
        if (bitmap != null && scale != 1) {
            resizeBmp = scaleImg(bitmap, scale);
        }
        return resizeBmp;
    }

    public static Bitmap scaleImg(Bitmap bitmap, float scale) {
        Bitmap resizeBmp = null;
        try {
            
            int bmpW = bitmap.getWidth();
            int bmpH = bitmap.getHeight();
            
            Matrix mt = new Matrix();
            
            mt.postScale(scale, scale);
            resizeBmp = Bitmap.createBitmap(bitmap, 0, 0, bmpW, bmpH, mt,
                    true);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (resizeBmp != bitmap) {
                bitmap.recycle();
            }
        }
        return resizeBmp;
    }
}

Related

1. scaleBitmapIfNeededToSize(Bitmap bitmap, long size)
2. scaleBitmapKeepRatio(Bitmap bitmap, int dstWidth, int dstHeight)
3. scaleToTextSize(Bitmap bmp, float textSize)
4. scaleToScreen(Activity activity, Bitmap bitmap)
5. scaleImage(Bitmap image, float scale)
6. scaleImg(Bitmap bitmap, int newWidth, int newHeight)
7. scaleImg(File file, int newWidth, int newHeight)
8. getScaleBitmap(Bitmap origialBitmap, int dstWidth, int dstHeight)
9. getScaleBitmap(Context context, int resId, int dstWidth, int dstHeight)