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);
	}
}