Android 马赛克(Mosaics)效果
jopen
9年前
layout: post
title: Android 马赛克(Mosaics)效果
date: 2015-12-13
categories: blog
tags: [技术,Android]
category: Android
description: 使用两种不同的方案实现Android平台下的马赛克效果
前几天看见开源项目[ExplosionField]效果好赞,看了下代码,他的实现大致就是在原界面之上覆盖一成自定义的View,获取到点击的那个View的内容(Bitmap),然后在覆盖的那个自定义View的特定位置画出来,之后就是对这个Bitmap做一些列拆分,变化重绘的过程.在这里根据他对bitmap的拆分,感觉用来实现Bitmap的效果也是不错的,就试着做一做.
在这里介绍使用两种方式实现马赛克效果.开始之前先看看效果
Screenshot from 2015-12-13 19-09-50.png
</div> 感觉还可以
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直接绘制
public static Bitmap getMosaicsBitmap(Bitmap bmp, double precent) { long start = System.currentTimeMillis(); int bmpW = bmp.getWidth(); int bmpH = bmp.getHeight(); Bitmap resultBmp = Bitmap.createBitmap(bmpW, bmpH, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(resultBmp); Paint paint = new Paint(); double unit; if (precent == 0) { unit = bmpW; } else { unit = 1 / precent; } double resultBmpW = bmpW / unit; double resultBmpH = bmpH / unit; for (int i = 0; i < resultBmpH; i++) { for (int j = 0; j < resultBmpW; j++) { int pickPointX = (int) (unit * (j + 0.5)); int pickPointY = (int) (unit * (i + 0.5)); int color; if (pickPointX >= bmpW || pickPointY >= bmpH) { color = bmp.getPixel(bmpW / 2, bmpH / 2); } else { color = bmp.getPixel(pickPointX, pickPointY); } paint.setColor(color); canvas.drawRect((int) (unit * j), (int) (unit * i), (int) (unit * (j + 1)), (int) (unit * (i + 1)), paint); } } canvas.setBitmap(null); long end = System.currentTimeMillis(); Log.v(TAG, "DrawTime:" + (end - start)); return resultBmp; } -
修改像素点
public static Bitmap getMosaicsBitmaps(Bitmap bmp, double precent) { long start = System.currentTimeMillis(); int bmpW = bmp.getWidth(); int bmpH = bmp.getHeight(); int[] pixels = new int[bmpH * bmpW]; bmp.getPixels(pixels, 0, bmpW, 0, 0, bmpW, bmpH); int raw = (int) (bmpW * precent); int unit; if (raw == 0) { unit = bmpW; } else { unit = bmpW / raw; //原来的unit*unit像素点合成一个，使用原左上角的值 } if (unit >= bmpW || unit >= bmpH) { return getMosaicsBitmap(bmp, precent); } for (int i = 0; i < bmpH; ) { for (int j = 0; j < bmpW; ) { int leftTopPoint = i * bmpW + j; for (int k = 0; k < unit; k++) { for (int m = 0; m < unit; m++) { int point = (i + k) * bmpW + (j + m); if (point < pixels.length) { pixels[point] = pixels[leftTopPoint]; } } } j += unit; } i += unit; } long end = System.currentTimeMillis(); Log.v(TAG, "DrawTime:" + (end - start)); return Bitmap.createBitmap(pixels, bmpW, bmpH, Bitmap.Config.ARGB_8888); } 从效率上来看,第二中方式效率会高10倍,只要是因为第一种方式绘制的次数太多了,而绘制是比较费时间的.这里,特别提示,不要在大量的循环语句内部使用Log.v(...),这是一个很耗时间的操作.