Question

我试图访问每个像素，操纵它然后将其保存回系统。但是生成的图像总是翻转和旋转，为什么会这样？这是我输入的代码：

 BufferedImage input_image=ImageIO.read(new File("F:\\sophie4.png"));
 int result[][] = convertTo2DWithoutUsingGetRGB(input_image);

 private static int[][] convertTo2DWithoutUsingGetRGB(BufferedImage image) {

      final byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
      final int width = image.getWidth();
      final int height = image.getHeight();
      final boolean hasAlphaChannel = image.getAlphaRaster() != null;

      int[][] result = new int[height][width];
      if (hasAlphaChannel) {
         final int pixelLength = 4;
         for (int pixel = 0, row = 0, col = 0; pixel < pixels.length; pixel += pixelLength) {
            int argb = 0;
            argb += (((int) pixels[pixel] & 0xff) << 24); // alpha
            argb += ((int) pixels[pixel + 1] & 0xff); // blue
            argb += (((int) pixels[pixel + 2] & 0xff) << 8); // green
            argb += (((int) pixels[pixel + 3] & 0xff) << 16); // red
            result[row][col] = argb;
            col++;
            if (col == width) {
               col = 0;
               row++;
            }
         }
      } else {
         final int pixelLength = 3;
         for (int pixel = 0, row = 0, col = 0; pixel < pixels.length; pixel += pixelLength) {
            int argb = 0;
            argb += -16777216; // 255 alpha
            argb += ((int) pixels[pixel] & 0xff); // blue
            argb += (((int) pixels[pixel + 1] & 0xff) << 8); // green
            argb += (((int) pixels[pixel + 2] & 0xff) << 16); // red
            result[row][col] = argb;
            col++;
            if (col == width) {
               col = 0;
               row++;
            }
         }
      }

      return result;
   }

这样，我得到像素，但即使不处理像素，如果我输出图像，它总是翻转..这是我的输出代码：

 BufferedImage image = new BufferedImage(result.length, result[0].length, BufferedImage.TYPE_INT_RGB);
    for (int row = 0; row  < result.length; row ++) {
        for (int col = 0; col < result[row].length; col++) {
            image.setRGB(row, col, result[row][col]);
        }
    }

File ImageFile = new File("path");
    try {
        ImageIO.write(image, "png", ImageFile);
    } catch (IOException e) {
        e.printStackTrace();
    }

您可以在下面看到输入和输出图像

Answer 1

你感到困惑（或者至少我是），因为你的结果是高度和宽度（不是宽度x高度，这对我来说更有意义），所以，而不是......

BufferedImage image = new BufferedImage(result.length, result[0].length, BufferedImage.TYPE_INT_RGB);

它应该是......

BufferedImage image = new BufferedImage(result[0].length, result.length, BufferedImage.TYPE_INT_RGB);

和

image.setRGB(row, col, result[row][col]);

应该是

image.setRGB(col, row, result[row][col]); // See why that's consfusing

Java为什么我的结果图像总是翻转和旋转？

1 个答案: