在 Java 中垂直翻转原始图像

发布于 2024-10-05 14:46:45 字数 969 浏览 5 评论 0原文

我需要在 Java 中翻转一个原始图像，该图像的行已反转。我所说的倒置是指图像的第一行存储在文件的末尾。

我设法通过使用辅助缓冲区对图像行重新排序来实现我想要的效果。我在下面包含了我的代码。

我认为这可以通过翻译坐标来优化，避免内存复制。我尝试实现一个可以反转行的 DataBuffer，但我使用的栅格需要 DataBufferByte （最终类）。

有谁知道更优化的方式来做我想做的事？

谢谢

...
int w = 640;
int h = 480;
byte[] flippedData = new byte[640*480*4];
int scanLineLength = w*4;
for(int i=0;i!=h; ++i) {
  System.arraycopy(originalData, scanLineLength*i, flippedData, scanLineLength*(h-i)-scanLineLength, scanLineLength);
}

DataBuffer db = new DataBufferByte(flippedData,flippedData.length);
WritableRaster raster = Raster.createInterleavedRaster(db, w, h, scanLineLength, 4, new int[]{2,1,0}, new Point(0,0));
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_sRGB);
ColorModel cm = new ComponentColorModel(cs, false, false, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);

BufferedImage img = new BufferedImage(cm, raster, false, null);
ImageIO.write(img, "JPEG", new File("out.jpg"));

原文

I need to flip in Java a raw image that has her rows inverted. By inverted I mean, the first row of the image is stored at the end of a file.

I managed to achive what I want by reordering the image rows using an auxiliar buffer. I included my code below.

I think this can be optimized by translating the coordinates, avoiding the memory copy. I tried to implement a DataBuffer that would invert the rows, but the raster I'm using requires a DataBufferByte (a final class).

Does anyone knows a more optimized way of doing what I want?

Thank you

...
int w = 640;
int h = 480;
byte[] flippedData = new byte[640*480*4];
int scanLineLength = w*4;
for(int i=0;i!=h; ++i) {
  System.arraycopy(originalData, scanLineLength*i, flippedData, scanLineLength*(h-i)-scanLineLength, scanLineLength);
}

DataBuffer db = new DataBufferByte(flippedData,flippedData.length);
WritableRaster raster = Raster.createInterleavedRaster(db, w, h, scanLineLength, 4, new int[]{2,1,0}, new Point(0,0));
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_sRGB);
ColorModel cm = new ComponentColorModel(cs, false, false, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);

BufferedImage img = new BufferedImage(cm, raster, false, null);
ImageIO.write(img, "JPEG", new File("out.jpg"));

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