Paint，ColorMatrix(颜色矩阵)实现滤镜效果及矩阵运算_颜色矩阵的运算

/**
 * 4x5 matrix for transforming the color and alpha components of a Bitmap.
 * The matrix can be passed as single array, and is treated as follows:
 *用于转换位图的颜色和alpha组成的4x5矩阵。
 矩阵可以作为单个数组传递，并按照以下方式进行处理
 * <pre>
 *  [ a, b, c, d, e,
 *    f, g, h, i, j,
 *    k, l, m, n, o,
 *    p, q, r, s, t ]</pre>
 *
 * <p>
 * When applied to a color <code>[R, G, B, A]</code>, the resulting color
 * is computed as:
 *当应用到一种颜色的时候，它的颜色是R，G，B，A
 *计算为:
 * </p>
 *
 * <pre>
 *   R&rsquo; = a*R + b*G + c*B + d*A + e;
 *   G&rsquo; = f*R + g*G + h*B + i*A + j;
 *   B&rsquo; = k*R + l*G + m*B + n*A + o;
 *   A&rsquo; = p*R + q*G + r*B + s*A + t;</pre>
 *
 * <p>
 * That resulting color <code>[R&rsquo;, G&rsquo;, B&rsquo;, A&rsquo;]</code>
 * then has each channel clamped to the <code>0</code> to <code>255</code>
 * range.
 * </p>
 *产生的颜色是R'G'B'，A'/码
 然后每个频道都被夹在“0”到“255”的代码中范围
 *
 * <p>
 * The sample ColorMatrix below inverts incoming colors by scaling each
 * channel by <code>-1</code>, and then shifting the result up by
 * <code>255</code> to remain in the standard color space.
 * </p>
 *
 * <pre>
 *   [ -1, 0, 0, 0, 255,
 *     0, -1, 0, 0, 255,
 *     0, 0, -1, 0, 255,
 *     0, 0, 0, 1, 0 ]</pre>
 */

Paint paint;
Bitmap bitmap;

private void init() {
    paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    paint.setColor(Color.RED);
    bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.timg);//获取要给做滤镜效果的图片
}

rets = new Rect("","","","")//确定绘制形状

canvas.drawBitmap(bitmap,null, 

rets ,paint);

paint.reset();
paint.setColor(Color.RED);

    //颜色矩阵

ColorMatrix colorMartrix = new ColorMatrix(new float[]{
        1,0,0,0,10,
        0, 0,0,0,10,
        0,0,0,0,0,
        0,0,0,0.5F,10,
});

Rect rect1 = new Rect(50,20 + bitmap.getHeight(),bitmap.getWidth()+100,bitmap.getHeight() * 2);
paint.setColorFilter(new ColorMatrixColorFilter(colorMartrix));
canvas.drawBitmap(bitmap,null, rect1,paint);

//滤镜
setContentView(new FilterView(this));

ColorMatrix colorMartrix = new ColorMatrix(new float[]{
        -1, 0, 0, 0, 255,
        0, -1, 0, 0, 255,
        0, 0, -1, 0, 255,
        0, 0, 0, 1, 0
});

ColorMatrix colorMartrix = new ColorMatrix(new float[]{
        1/2f,1/2f,1/2f,0,0,
        1/3f, 1/3f,1/3f,0,0,
        1/4f,1/4f,1/4f,0,0,
        0,0,0,1,0,
});