android 下滤镜效果的实现

滤镜过滤颜色已实现，简单版本可通过下面代码的3个参数实现黑白、红、绿。。。等7种过滤(RGB的7种组合)。

 

理论上讲可以过滤为任意颜色。调整混合结果的比值就行了。

 

 

code:

public void drawBitmap(Canvas canvas, Bitmap bitmap, boolean r, boolean g, boolean b) {
        ColorMatrix cm = new ColorMatrix();
        float[] m = cm.getArray();
        setColorFilterMatrix(m, r, g, b);
        Paint pt = new Paint();
        pt.setColorFilter(new ColorMatrixColorFilter(cm));
        canvas.drawBitmap(bitmap, 0, 0, pt);
    }

    public void setColorFilterMatrix(float[] m, boolean r, boolean g, boolean b) {
        final float R = 0.213f;
        final float G = 0.715f;
        final float B = 0.072f;

        m[0] = 0;
        m[6] = 0;
        m[12] = 0;

        if (r) {
            m[0] = R; m[1] = G; m[2] = B;
        }
        if (g) {
            m[5] = R; m[6] = G; m[7] = B;
        }
        if (b) {
            m[10] = R; m[11] = G; m[12] = B;
        }
    }