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();}@Overrideprotected 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);}}