算法原理：将当前像素点的RGB值分别与255之差后的值作为当前点的RGB值。

例：

ABC

求B点的底片效果：

B.r = 255 - B.r;

B.g = 255 - B.g;

B.b = 255 - B.b;

效果图：

                     效果图                                                                     原图

代码：

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];          //获取RGB分量          pixelsA = Color.alpha(color);          pixelsR = Color.red(color);          pixelsG = Color.green(color);          pixelsB = Color.blue(color);                    //转换          pixelsR = (255 - pixelsR);          pixelsG = (255 - pixelsG);          pixelsB = (255 - pixelsB);          //均小于等于255大于等于0          if(pixelsR > 255){           pixelsR = 255;          }          else if(pixelsR < 0){           pixelsR = 0;          }          if(pixelsG > 255){           pixelsG = 255;          }          else if(pixelsG < 0){            pixelsG = 0;          }          if(pixelsB > 255){           pixelsB = 255;          }          else if(pixelsB < 0){           pixelsB = 0;          }          //根据新的RGB生成新像素          newPixels[i] = Color.argb(pixelsA, pixelsR, pixelsG, pixelsB);                  }        //根据新像素生成新图片        bitmap.setPixels(newPixels, 0, width, 0, 0, width, height);  canvas.drawBitmap(bitmap,0,0,myPaint); }}