从BufferedImage转换为SWT图像

Question

经过深思熟虑后，我发现了一些将BufferedImage转换为SWT图像的代码（不用费心去读取它）：

public static ImageData convertToSWT(BufferedImage bufferedImage) {
    if (bufferedImage.getColorModel() instanceof DirectColorModel) {
        DirectColorModel colorModel = (DirectColorModel) bufferedImage.getColorModel();
        PaletteData palette = new PaletteData(
            colorModel.getRedMask(),
            colorModel.getGreenMask(),
            colorModel.getBlueMask()
        );
        ImageData data = new ImageData(
            bufferedImage.getWidth(),
            bufferedImage.getHeight(), colorModel.getPixelSize(),
            palette
        );
        WritableRaster raster = bufferedImage.getRaster();
        int[] pixelArray = new int[3];
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                raster.getPixel(x, y, pixelArray);
                int pixel = palette.getPixel(
                    new RGB(pixelArray[0], pixelArray[1], pixelArray[2])
                );
                data.setPixel(x, y, pixel);
            }
        }
        return data;
    } else if (bufferedImage.getColorModel() instanceof IndexColorModel) {
        IndexColorModel colorModel = (IndexColorModel) bufferedImage.getColorModel();
        int size = colorModel.getMapSize();
        byte[] reds = new byte[size];
        byte[] greens = new byte[size];
        byte[] blues = new byte[size];
        colorModel.getReds(reds);
        colorModel.getGreens(greens);
        colorModel.getBlues(blues);
        RGB[] rgbs = new RGB[size];
        for (int i = 0; i < rgbs.length; i++) {
            rgbs[i] = new RGB(reds[i] & 0xFF, greens[i] & 0xFF, blues[i] & 0xFF);
        }
        PaletteData palette = new PaletteData(rgbs);
        ImageData data = new ImageData(
            bufferedImage.getWidth(),
            bufferedImage.getHeight(),
            colorModel.getPixelSize(),
            palette
        );
        data.transparentPixel = colorModel.getTransparentPixel();
        WritableRaster raster = bufferedImage.getRaster();
        int[] pixelArray = new int[1];
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                raster.getPixel(x, y, pixelArray);
                data.setPixel(x, y, pixelArray[0]);
            }
        }
        return data;
    }
    return null;
}

（在此处找到： http ： //www.java2s.com/Code/Java/SWT-JFace-Eclipse/ConvertsabufferedimagetoSWTImageData.htm ）。

我测试过它，它运行得很好。 问题是我不理解它（我最好的猜测是它使用两者的原始数据接口来进行传输）。 在我看来，更简单的解决方案是将BufferedImage写入ByteArrayOutputStream ，然后使用ByteArrayInputStream将其读回SWT图像。 这个解决方案有什么问题吗？ 速度怎么样？

这种转换是必要的，因为所有的图像大小调整库都用于AWT，但我用SWT显示图像。

谢谢！

Answer 1

这是一个更完整的版本...问题中发布的版本对我不起作用。

/**
 * snippet 156: convert between SWT Image and AWT BufferedImage.
 * <p>
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
public static ImageData convertToSWT(BufferedImage bufferedImage) {
    if (bufferedImage.getColorModel() instanceof DirectColorModel) {
        /*
        DirectColorModel colorModel = (DirectColorModel)bufferedImage.getColorModel();
        PaletteData palette = new PaletteData(
                colorModel.getRedMask(),
                colorModel.getGreenMask(),
                colorModel.getBlueMask());
        ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(),
                colorModel.getPixelSize(), palette);
        WritableRaster raster = bufferedImage.getRaster();
        int[] pixelArray = new int[3];
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                raster.getPixel(x, y, pixelArray);
                int pixel = palette.getPixel(new RGB(pixelArray[0], pixelArray[1], pixelArray[2]));
                data.setPixel(x, y, pixel);
            }
        }
        */
        DirectColorModel colorModel = (DirectColorModel)bufferedImage.getColorModel();
        PaletteData palette = new PaletteData(
                colorModel.getRedMask(),
                colorModel.getGreenMask(),
                colorModel.getBlueMask());
        ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(),
                colorModel.getPixelSize(), palette);
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                int rgb = bufferedImage.getRGB(x, y);
                int pixel = palette.getPixel(new RGB((rgb >> 16) & 0xFF, (rgb >> 8) & 0xFF, rgb & 0xFF));
                data.setPixel(x, y, pixel);
                if (colorModel.hasAlpha()) {
                    data.setAlpha(x, y, (rgb >> 24) & 0xFF);
                }
            }
        }
        return data;
    }
    else if (bufferedImage.getColorModel() instanceof IndexColorModel) {
        IndexColorModel colorModel = (IndexColorModel)bufferedImage.getColorModel();
        int size = colorModel.getMapSize();
        byte[] reds = new byte[size];
        byte[] greens = new byte[size];
        byte[] blues = new byte[size];
        colorModel.getReds(reds);
        colorModel.getGreens(greens);
        colorModel.getBlues(blues);
        RGB[] rgbs = new RGB[size];
        for (int i = 0; i < rgbs.length; i++) {
            rgbs[i] = new RGB(reds[i] & 0xFF, greens[i] & 0xFF, blues[i] & 0xFF);
        }
        PaletteData palette = new PaletteData(rgbs);
        ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(),
                colorModel.getPixelSize(), palette);
        data.transparentPixel = colorModel.getTransparentPixel();
        WritableRaster raster = bufferedImage.getRaster();
        int[] pixelArray = new int[1];
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                raster.getPixel(x, y, pixelArray);
                data.setPixel(x, y, pixelArray[0]);
            }
        }
        return data;
    }
    else if (bufferedImage.getColorModel() instanceof ComponentColorModel) {
        ComponentColorModel colorModel = (ComponentColorModel)bufferedImage.getColorModel();
        //ASSUMES: 3 BYTE BGR IMAGE TYPE
        PaletteData palette = new PaletteData(0x0000FF, 0x00FF00,0xFF0000);
        ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(),
                colorModel.getPixelSize(), palette);
        //This is valid because we are using a 3-byte Data model with no transparent pixels
        data.transparentPixel = -1;
        WritableRaster raster = bufferedImage.getRaster();
        int[] pixelArray = new int[3];
        for (int y = 0; y < data.height; y++) {
            for (int x = 0; x < data.width; x++) {
                raster.getPixel(x, y, pixelArray);
                int pixel = palette.getPixel(new RGB(pixelArray[0], pixelArray[1], pixelArray[2]));
                data.setPixel(x, y, pixel);
            }
        }
        return data;
    }
    return null;
}

Answer 2

代码的复杂性主要是由于BufferedImage的两种可能的颜色模型。 我不认为你可以在这方面有所改进。 首先，使用中间Stream将要求两个图像系统具有通用格式，并且与Stream的转换Stream当前代码慢。