android 图片操作之色彩变换

本博客为 http://www.imooc.com/video/6480 的笔记

1 可以通过 ColorMatrix 类 ,操作底层维护的5*4的float颜色变换矩阵，

来改变图片的三基色,透明度等来操作图片.

2 通过获取图片上所有像素点的信息,通过科学公式的变换

来操作像素点来达到操作图片的效果

//图像处理的工具类

[code]
/**
 * 图像处理的帮助类
 * 
 * */

public class ImageHelper {

    /**
     * 底部起始是操作了float类型的数组
     * @param bm
     * @param hue
     * @param saturation
     * @param lum
     * @return
     */
    public static Bitmap ImageEffect(Bitmap bm,float hue,float saturation,float lum){

            Bitmap bmp = Bitmap.createBitmap(bm.getWidth(),
                    bm.getHeight(), Bitmap.Config.ARGB_8888);
            Canvas canvas = new Canvas(bmp);
            Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);

            ColorMatrix hueMatrix = new ColorMatrix();
            hueMatrix.setRotate(0, hue);
            hueMatrix.setRotate(1, hue);
            hueMatrix.setRotate(2, hue);

            ColorMatrix saturationMatrix = new ColorMatrix();
            saturationMatrix.setSaturation(saturation);

            ColorMatrix lumMatrix = new ColorMatrix();
            lumMatrix.setScale(lum, lum, lum, 1);

            ColorMatrix imageMatrix = new ColorMatrix();
            imageMatrix.postConcat(hueMatrix);
            imageMatrix.postConcat(saturationMatrix);
            imageMatrix.postConcat(lumMatrix);

            paint.setColorFilter(new ColorMatrixColorFilter(imageMatrix));
            canvas.drawBitmap(bm, 0, 0, paint);

            return bmp;
    }

    /**
     * 
     * @param bitmap 原图片
     * @param data  长度为20 的数组 数组中的值为0或者1
     * @return  处理后的图片
     */
    public static Bitmap ImageEffect(Bitmap bitmap ,float[] data){

        if(data==null)
            return null;

        if(data.length!=20)
            return null;

        //在内存中的图片
        Bitmap bm=Bitmap.createBitmap(bitmap.getWidth(),
                           bitmap.getHeight(),
                           Bitmap.Config.ARGB_8888);
        ColorMatrix matrix=new ColorMatrix(data);
        Canvas mCanvas=new Canvas(bm);
        Paint mPaint=new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setDither(true);

        mPaint.setColorFilter(new ColorMatrixColorFilter(matrix));
        mCanvas.drawBitmap(bm, 0, 0,mPaint);
        return bm;
    }

    /**
     * 将图片转换成底色的效果
     * @param bitmap
     * @return
     */
    public static Bitmap handleImageNegative(Bitmap bm){

        int width = bm.getWidth();
        int height = bm.getHeight();
        int color;
        int r, g, b, a;

        Bitmap bmp = Bitmap.createBitmap(width, height
                , Bitmap.Config.ARGB_8888);

        int[] oldPx = new int[width * height];
        int[] newPx = new int[width * height];
        bm.getPixels(oldPx, 0, width, 0, 0, width, height);

        for (int i = 0; i < width * height; i++) {
            color = oldPx[i];
            r = Color.red(color);
            g = Color.green(color);
            b = Color.blue(color);
            a = Color.alpha(color);

            //底片效果的转换公式
            r = 255 - r;
            g = 255 - g;
            b = 255 - b;

            if (r > 255) {
                r = 255;
            } else if (r < 0) {
                r = 0;
            }
            if (g > 255) {
                g = 255;
            } else if (g < 0) {
                g = 0;
            }
            if (b > 255) {
                b = 255;
            } else if (b < 0) {
                b = 0;
            }
            newPx[i] = Color.argb(a, r, g, b);
        }

        bmp.setPixels(newPx, 0, width, 0, 0, width, height);
        return bmp;
    }

    /**
     * 老照片的处理效果
     * @param bm
     * @return
     */
      public static Bitmap handleImagePixelsOldPhoto(Bitmap bm) {
            Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(),
                    Bitmap.Config.ARGB_8888);
            int width = bm.getWidth();
            int height = bm.getHeight();
            int color = 0;
            int r, g, b, a, r1, g1, b1;

            int[] oldPx = new int[width * height];
            int[] newPx = new int[width * height];

            bm.getPixels(oldPx, 0, bm.getWidth(), 0, 0, width, height);
            for (int i = 0; i < width * height; i++) {
                color = oldPx[i];
                a = Color.alpha(color);
                r = Color.red(color);
                g = Color.green(color);
                b = Color.blue(color);

                //老照片处理效果的公式
                r1 = (int) (0.393 * r + 0.769 * g + 0.189 * b);
                g1 = (int) (0.349 * r + 0.686 * g + 0.168 * b);
                b1 = (int) (0.272 * r + 0.534 * g + 0.131 * b);

                if (r1 > 255) {
                    r1 = 255;
                }
                if (g1 > 255) {
                    g1 = 255;
                }
                if (b1 > 255) {
                    b1 = 255;
                }

                newPx[i] = Color.argb(a, r1, g1, b1);
            }
            bmp.setPixels(newPx, 0, width, 0, 0, width, height);
            return bmp;
        }

      /**
       * 浮雕效果
       */
        public static Bitmap handleImagePixelsRelief(Bitmap bm) {
            Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(),
                    Bitmap.Config.ARGB_8888);
            int width = bm.getWidth();
            int height = bm.getHeight();
            int color = 0, colorBefore = 0;
            int a, r, g, b;
            int r1, g1, b1;

            int[] oldPx = new int[width * height];
            int[] newPx = new int[width * height];

            bm.getPixels(oldPx, 0, bm.getWidth(), 0, 0, width, height);
            for (int i = 1; i < width * height; i++) {

                //像素点的算法
                colorBefore = oldPx[i - 1];
                a = Color.alpha(colorBefore);
                r = Color.red(colorBefore);
                g = Color.green(colorBefore);
                b = Color.blue(colorBefore);

                color = oldPx[i];
                r1 = Color.red(color);
                g1 = Color.green(color);
                b1 = Color.blue(color);

                r = (r - r1 + 127);
                g = (g - g1 + 127);
                b = (b - b1 + 127);
                if (r > 255) {
                    r = 255;
                }
                if (g > 255) {
                    g = 255;
                }
                if (b > 255) {
                    b = 255;
                }
                newPx[i] = Color.argb(a, r, g, b);
            }
            bmp.setPixels(newPx, 0, width, 0, 0, width, height);
            return bmp;
        }

}