android图像处理(3) 浮雕效果

这篇将讲到图片特效处理的浮雕效果。跟前面一样是对像素点进行处理，算法是通用的。

算法原理：用前一个像素点的RGB值分别减去当前像素点的RGB值并加上127作为当前像素点的RGB值。

例：

ABC

求B点的浮雕效果如下：

B.r = C.r - B.r + 127;

B.g = C.g - B.g + 127;

B.b = C.b - B.b + 127;

注意RGB值在0~255之间。

效果图：

                     原图                                                                              效果图

package com.color;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.widget.ImageView;

public class ColorView extends ImageView {

    private Paint myPaint = null;
    private Bitmap bitmap = null;
    private int width,height;
    private int[] oldPixels;
    private int[] newPixels;
    private int color,color2;
    private int pixelsR,pixelsG,pixelsB,pixelsA,pixelsR2,pixelsG2,pixelsB2;

    public ColorView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        bitmap = BitmapFactory.decodeResource(context.getResources(),R.drawable.ww);
        width = bitmap.getWidth();
        height = bitmap.getHeight();
        oldPixels = new int[width*height];
        newPixels = new int[width*height];
        invalidate();
    }
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        //获取像素
        bitmap.getPixels(oldPixels, 0, width, 0, 0, width, height);

        for(int i = 1;i < height*width; i++){
                color = oldPixels[i-1];
                //前一个像素
                pixelsR = Color.red(color);
                pixelsG = Color.green(color);
                pixelsB = Color.blue(color);
                //当前像素
                color2 = oldPixels[i];
                pixelsR2 = Color.red(color2);
                pixelsG2 = Color.green(color2);
                pixelsB2 = Color.blue(color2);

                pixelsR = (pixelsR - pixelsR2 + 127);
                pixelsG = (pixelsG - pixelsG2 + 127);
                pixelsB = (pixelsB - pixelsB2 + 127);
                //均小于等于255
                if(pixelsR > 255){
                    pixelsR = 255;
                }

                if(pixelsG > 255){
                    pixelsG = 255;
                }

                if(pixelsB > 255){
                    pixelsB = 255;
                }

                newPixels[i] = Color.argb(pixelsA, pixelsR, pixelsG, pixelsB);

        }
        bitmap.setPixels(newPixels, 0, width, 0, 0, width, height);
        canvas.drawBitmap(bitmap,0,0,myPaint);
    }
}