经典的图像缩放.doc

几个经典的图像缩放的函数收集了几个图像缩放的函数，可能实现的方式很多，感觉这几个不错的，分享下说明：以下函数都是基于MIDP2.0的，缩放后保留透明色。代码1，函数 resizeImagepublic static Image resizeImage(Image src, int destW, int destH) int srcW = src.getWidth(); int srcH = src.getHeight(); / create pixel arrays int destPixels = new intdestW * destH; / array to hold destination / pixels int srcPixels = new intsrcW * srcH; / array with sources pixels src.getRGB(srcPixels, 0, srcW, 0, 0, srcW, srcH); / simple point smapled resizing / loop through the destination pixels, find the matching pixel on / the source and use that for (int destY = 0; destY destH; +destY) for (int destX = 0; destX desH ? srcH : desH; for (int i = 0; i distance) tems -= distance; sb+; if (temd distance) temd -= distance; db+; sb = 0; db = 0; tems = 0; temd = 0; distance = srcW desW ? srcW : desW; for (int i = 0; i distance) tems -= distance; sb+; if (temd distance) temd -= distance; db+; / 生成放大缩小后图形像素buf int desBuf = new intdesW * desH; int dx = 0; int dy = 0; int sy = 0; int oldy = -1; for (int i = 0; i desH; i+) if (oldy = tabYi) System.arraycopy(desBuf, dy - desW, desBuf, dy, desW); else dx = 0; for (int j = 0; j 0; y-) for (int x = newWidth, XE = 0; x 0; x-) rawOutputoutOffset+ = rawInputinOffset; inOffset += XD; XE += XR; if (XE = newWidth) XE -= newWidth; inOffset+; inOffset += YD; YE += YR; if (YE = newHeight) YE -= newHeight; inOffset += original.getWidth(); return Image.createRGBImage(rawOutput, newWidth, newHeight, true); 我将100*100的图放大到200*200后对比了一下，ZoomImage生成的图片和另外两个函数生成的图像有点区别，感觉ZoomImage的效果好一点。再放大点就基本一样了看不出区别了。代码4 /*图像变换*/ public Image scaleImage(Image src,int scales1,int scales2) return transImage(src,src.getWidth()*scales1/scales2,src.getHeight()*scales1/scales2); public Image transImage(Image src, int w, int h) int srcW = src.getWidth(); int srcH = src.getHeight(); int dstW=w,dstH=h; Image tmp = Image.createImage(dstW, srcH); Graphics g = tmp.getGraphics(); int scale=16; int delta = (srcW scale) / dstW;/扫描长度 int pos = delta / 2;/扫描位置 for (int x = 0; x scale), 0, Graphics.LEFT | Graphics.TOP); pos += delta; Image dst = Image.createImage( dstW, dstH); g = dst.getGraphics(); delta = (srcH sca