Android图片处理（进阶）

• 示例图

示例图片.jpg

如图，将上述图片处理成各种样式

• 将彩色图片转化为灰图

灰图.jpg

/** 
 * 将彩色图转换为灰度图 
 * @param img 位图 
 * @return 返回转换好的位图 
 */ 
 public Bitmap convertGreyImg(Bitmap img) { 
   int width = img.getWidth(); //获取位图的宽 
   int height = img.getHeight(); //获取位图的高 
   int []pixels = new int[width * height]; //通过位图的大小创建像素点数组 
   img.getPixels(pixels, 0, width, 0, 0, width, height); 
   int alpha = 0xFF << 24; 
   for(int i = 0; i < height; i++) { 
     for(int j = 0; j < width; j++) { 
       int grey = pixels[width * i + j]; 
       int red = ((grey & 0x00FF0000 ) >> 16); 
       int green = ((grey & 0x0000FF00) >> 8); 
       int blue = (grey & 0x000000FF); 
       grey = (int)((float) red * 0.3 + (float)green * 0.59 + (float)blue * 0.11); 
       grey = alpha | (grey << 16) | (grey << 8) | grey; 
       pixels[width * i + j] = grey; 
       } 
     } 
   Bitmap result = Bitmap.createBitmap(width, height, Config.RGB_565); 
   result.setPixels(pixels, 0, width, 0, 0, width, height); 
   return result; 
 } 

• 将图片转成圆角图

圆角图.jpg

    public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, float roundPx) {

        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
        final RectF rectF = new RectF(rect);

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);

        return output;
    }

• 图片添加倒影效果

倒影.jpg

/**
     * 获得带倒影的图片方法
     */
    public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap) {
        final int reflectionGap = 4;
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();

        Matrix matrix = new Matrix();
        matrix.preScale(1, -1);

        Bitmap reflectionImage = Bitmap.createBitmap(bitmap, 0, height / 2,
                width, height / 2, matrix, false);

        Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
                (height + height / 2), Config.ARGB_8888);

        Canvas canvas = new Canvas(bitmapWithReflection);
        canvas.drawBitmap(bitmap, 0, 0, null);
        Paint deafalutPaint = new Paint();
        canvas.drawRect(0, height, width, height + reflectionGap, deafalutPaint);

        canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

        Paint paint = new Paint();
        LinearGradient shader = new LinearGradient(0, bitmap.getHeight(), 0,
                bitmapWithReflection.getHeight() + reflectionGap, 0x70ffffff,
                0x00ffffff, TileMode.CLAMP);
        paint.setShader(shader);
        // Set the Transfer mode to be porter duff and destination in
        paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
        // Draw a rectangle using the paint with our linear gradient
        canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
                + reflectionGap, paint);
        return bitmapWithReflection;
    }

• 添加水印

右下角水印.jpg

    /**
     * create the bitmap from a byte array 生成水印图片
     * 
     * @param src
     *            要添加水印的图片
     * @param 水印
     * @return 添加了水印的图片
     */
    private Bitmap createBitmap(Bitmap src, Bitmap watermark) {
        String tag = "createBitmap";
        Log.d(tag, "create a new bitmap");
        if (src == null) {
            return null;
        }

        int w = src.getWidth();
        int h = src.getHeight();
        int ww = watermark.getWidth();
        int wh = watermark.getHeight();
        // create the new blank bitmap
        Bitmap newb = Bitmap.createBitmap(w, h, Config.ARGB_8888);// 创建一个新的和SRC长度宽度一样的位图
        Canvas cv = new Canvas(newb);
        // draw src into
        cv.drawBitmap(src, 0, 0, null);// 在 0，0坐标开始画入src
        // draw watermark into
        cv.drawBitmap(watermark, w - ww + 5, h - wh + 5, null);// 在src的右下角画入水印
        // save all clip
        cv.save(Canvas.ALL_SAVE_FLAG);// 保存
        // store
        cv.restore();// 存储
        return newb;
    }

• View转成Bitmap

    /**
     * 把一个View的对象转换成bitmap
     */
    static Bitmap getViewBitmap(View v) {

        v.clearFocus();
        v.setPressed(false);

        // 能画缓存就返回false
        boolean willNotCache = v.willNotCacheDrawing();
        v.setWillNotCacheDrawing(false);
        int color = v.getDrawingCacheBackgroundColor();
        v.setDrawingCacheBackgroundColor(0);
        if (color != 0) {
            v.destroyDrawingCache();
        }
        v.buildDrawingCache();
        Bitmap cacheBitmap = v.getDrawingCache();
        if (cacheBitmap == null) {
            Log.e(TAG, "failed getViewBitmap(" + v + ")",
                    new RuntimeException());
            return null;
        }
        Bitmap bitmap = Bitmap.createBitmap(cacheBitmap);
        // Restore the view
        v.destroyDrawingCache();
        v.setWillNotCacheDrawing(willNotCache);
        v.setDrawingCacheBackgroundColor(color);
        return bitmap;
    }

相关链接：
图片处理（入门）

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