在MIDP1.0中开发者自己实现翻转，在MIDP2.0中系统已经提供了翻转方法，但有些机型翻转效果不正确（厂商实现问题），所以自己实现翻转方法。本想一次将图读到一个int数数组，然后进行变换，但如果图片过大，会内存溢出，所以通过对图片的每行进行变换来达到高效翻转。如果你有更高效的方法欢迎讨论。
import javax.microedition.lcdui.Graphics; import javax.microedition.lcdui.Image; /** */ /** * @功能：实现图片的高效翻转 * @作者: imuse * @MAIL: postzhu@hotmail.com * */ public class ImageUtil ... { /** *//** * 无变化 * */ public final static int TRANS_NONE = 0; /** *//** * 顺时针翻转90度 * */ public final static int TRANS_ROT90 = 5; /** *//** * 顺时针翻转180度 * */ public final static int TRANS_ROT180 = 3; /** *//** * 顺时针翻转270度 * */ public final static int TRANS_ROT270 = 6; /** *//** * 水平镜像翻转 * */ public final static int TRANS_MIRROR = 2; /** *//** * 水平镜像翻转并顺时针翻转90度 * */ public final static int TRANS_MIRROR_ROT90 = 7; /** *//** * 水平镜像翻转并顺时针翻转180度 * */ public final static int TRANS_MIRROR_ROT180 = 1; /** *//** * 水平镜像翻转并顺时针翻转270度 * */ public final static int TRANS_MIRROR_ROT270 = 4; /** *//** * @功能 实现图片的翻转 * @参数 Image srcImage 原图<br>int transform 翻转方向<br> * @返回值 转换后的图片 * */ public static Image transformImage(Image srcImage, int transform) ...{ int srcW = srcImage.getWidth(); int srcH = srcImage.getHeight(); Image imgRet = null; switch (transform) ...{ case TRANS_NONE: imgRet = srcImage; break; case TRANS_ROT90: ...{ /** *//** * 原: 目标: * 1234 951 * 5678 062 * 90ab a73 * b84 * */ int[] srcRGB = new int[srcW]; imgRet = Image.createImage(srcH, srcW); Graphics g = imgRet.getGraphics(); for (int i = 0; i < srcH; i++) ...{ srcImage.getRGB(srcRGB, 0, srcW, 0, i, srcW, 1); g.drawRGB(srcRGB, 0, 1, srcH - i - 1, 0, 1, srcW, true); } } break; case TRANS_ROT180: ...{ /** *//** * 原: 目标: * 1234 ba09 * 5678 8765 * 90ab 4321 * * */ int[] srcRGB = new int[srcW]; imgRet = Image.createImage(srcW, srcH); Graphics g = imgRet.getGraphics(); for (int i = 0; i < srcH; i++) ...{ srcImage.getRGB(srcRGB, 0, srcW, 0, i, srcW, 1); arrayExchange(srcRGB); g.drawRGB(srcRGB, 0, srcW, 0, srcH-1-i, srcW, 1, true); } } break; case TRANS_ROT270: ...{ /** *//** * 原: 目标: * 1234 48b * 5678 37a * 90ab 260 * 159 * */ int[] srcRGB = new int[srcW]; imgRet = Image.createImage(srcH, srcW); Graphics g = imgRet.getGraphics(); for (int i = 0; i < srcH; i++) ...{ srcImage.getRGB(srcRGB, 0, srcW, 0, i, srcW, 1); arrayExchange(srcRGB); g.drawRGB(srcRGB, 0, 1, i, 0, 1, srcW, true); } } break; case TRANS_MIRROR: ...{ /** *//** * 原: 目标: * 1234 4321 * 5678 8765 * 90ab ba09 * * */ int[] srcRGB = new int[srcW]; imgRet = Image.createImage(srcW, srcH); Graphics g = imgRet.getGraphics(); for (int i = 0; i < srcH; i++) ...{ srcImage.getRGB(srcRGB, 0, srcW, 0, i, srcW, 1); arrayExchange(srcRGB); g.drawRGB(srcRGB, 0, srcW, 0, i, srcW, 1, true); } } break; case TRANS_MIRROR_ROT90: ...{ /** *//** * 原: 目标: * 1234 b84 * 5678 a73 * 90ab 062 * 951 * */ int[] srcRGB = new int[srcW]; imgRet = Image.createImage(srcH, srcW); Graphics g = imgRet.getGraphics(); for (int i = 0; i < srcH; i++) ...{ srcImage.getRGB(srcRGB, 0, srcW, 0, i, srcW, 1); arrayExchange(srcRGB); g.drawRGB(srcRGB, 0, 1, srcH - i - 1, 0, 1, srcW, true); } } break; case TRANS_MIRROR_ROT180: ...{ /** *//** * 原: 目标: * 1234 90ab * 5678 5678 * 90ab 1234 * * */ int[] srcRGB = new int[srcW]; imgRet = Image.createImage(srcW, srcH); Graphics g = imgRet.getGraphics(); for (int i = 0; i < srcH; i++) ...{ srcImage.getRGB(srcRGB, 0, srcW, 0, i, srcW, 1); g.drawRGB(srcRGB, 0, srcW, 0, srcH-1-i, srcW, 1, true); } } break; case TRANS_MIRROR_ROT270: ...{ /** *//** * 原: 目标: * 1234 159 * 5678 260 * 90ab 37a * 48b * */ int[] srcRGB = new int[srcW]; imgRet = Image.createImage(srcH, srcW); Graphics g = imgRet.getGraphics(); for (int i = 0; i < srcH; i++) ...{ srcImage.getRGB(srcRGB, 0, srcW, 0, i, srcW, 1); g.drawRGB(srcRGB, 0, 1, i, 0, 1, srcW, true); } } break; default: imgRet = srcImage; break; } return imgRet; } /** *//** * @功能 翻转一个INT数组 * @参数 要转换的INT数组 * @返回值 无 * */ public static final void arrayExchange(int[] b)...{ int nCount = b.length; int nLen = nCount/2; nCount--; for (int i = 0; i < nLen; i++) ...{ int nTemp = b[i]; b[i] = b[nCount-i]; b[nCount-i] = nTemp; } }}