从Java中的超大图像文件读取区域

标准ImageIO允许您读取（大）图像区域，而无需先将整个图像读取到内存中。

Rectangle sourceRegion = new Rectangle(x, y, w, h); // The region you want to extractImageInputStream stream = ImageIO.createImageInputStream(input); // File or input streamIterator<ImageReader> readers = ImageIO.getImageReaders(stream);if (readers.hasNext()) {    ImageReader reader = readers.next();    reader.setInput(stream);    ImageReadParam param = reader.getDefaultReadParam();    param.setSourceRegion(sourceRegion); // Set region    BufferedImage image = reader.read(0, param); // Will read only the region specified}