这篇将讲到图片特效处理的底片效果。跟前面一样是对像素点进行处理,算法是通用的。
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);
- }
- }