java 图片缩放

最新推荐文章于 2022-10-21 19:02:03 发布

原创最新推荐文章于 2022-10-21 19:02:03 发布 · 365 阅读

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项目已经完毕，可为了以后方便我就把它的功能扩大了，总共写出三种经过对比，我拿出无论是缩小和放大都较为好的一篇，拿出来跟大家参考，同时希望大家能够提出一些意见：

public static Image ZoomImage(Image src, int desW, int desH) {
    Image desImg = null;
    int srcW = src.getWidth(); // 原始图像宽
    int srcH = src.getHeight(); // 原始图像高
    int[] srcBuf = new int[srcW * srcH]; // 原始图片像素信息缓存
    src.getRGB(srcBuf, 0, srcW, 0, 0, srcW, srcH);
    // 计算插值表
    int[] tabY = new int[desH];
    int[] tabX = new int[desW];
    int sb = 0;
    int db = 0;
    int tems = 0;
    int temd = 0;
    int distance = srcH > desH ? srcH : desH;
    for (int i = 0; i <= distance; i++) { /* 垂直方向 */
        tabY[db] = sb;
        tems += srcH;
        temd += desH;
        if (tems > 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; i++) { /* 水平方向 */
        tabX[db] = (short) sb;
        tems += srcW;
        temd += desW;
        if (tems > 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 int[desW * desH];
    int dx = 0;
    int dy = 0;
    int sy = 0;
    int oldy = -1;
    for (int i = 0; i < desH; i++) {
        if (oldy == tabY[i]) {
            System.arraycopy(desBuf, dy - desW, desBuf, dy, desW);
        } else {
            dx = 0;
            for (int j = 0; j < desW; j++) {
                desBuf[dy + dx] = srcBuf[sy + tabX[j]];
                dx++;
            }
            sy += (tabY[i] - oldy) * srcW;
        }
        oldy = tabY[i];
        dy += desW;
    }
    // 生成图片
    desImg = Image.createRGBImage(desBuf, desW, desH, true);
    return desImg;
}