Java SWT和lt之间的透明度-&燃气轮机；AWT图像转换

我创建了一个对话框，用户可以在其中浏览图像，然后查看在画布上绘制的图像预览。图像已缩放，以便在框中拟合时保持其纵横比。我使用了在中找到的调整大小的方法，包括将图像从SWT转换为AWT，执行调整大小，从AWT转换回SWT，最后在画布上绘制。由于此过程在时间和处理能力方面非常昂贵，因此如果图像大小正确，我选择跳过调整大小步骤，因此不需要以任何方式进行变换

在处理具有alpha透明度的图像时会出现此问题。在某些情况下，首先转换的具有透明度的图像绘制在具有黑色背景的画布上。同一图像的副本大小与画布的精确大小相同，因此未转换，其背景为白色

然而，情况并非总是如此。某些具有透明背景的图像无论是否已转换，都将始终显示为白色

是什么导致在SWT画布中，具有透明背景的图像以一种颜色覆盖另一种颜色绘制？AWT转换如何影响它，如果我愿意，我如何使其变得一致

以下是从另一个来源获取的转换代码：

public static BufferedImage convertToAWT (ImageData data) {
    ColorModel colorModel = null;
    PaletteData palette = data.palette;
    if (palette.isDirect) {
        colorModel = new DirectColorModel(data.depth, palette.redMask, palette.greenMask, palette.blueMask);
        BufferedImage bufferedImage = new BufferedImage(colorModel, colorModel.createCompatibleWritableRaster(data.width, data.height),
                false, null);
        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++) {
                int pixel = data.getPixel(x, y);
                RGB rgb = palette.getRGB(pixel);
                pixelArray[0] = rgb.red;
                pixelArray[1] = rgb.green;
                pixelArray[2] = rgb.blue;
                raster.setPixels(x, y, 1, 1, pixelArray);
            }
        }
        return bufferedImage;
    }
    else {
        RGB[] rgbs = palette.getRGBs();
        byte[] red = new byte[rgbs.length];
        byte[] green = new byte[rgbs.length];
        byte[] blue = new byte[rgbs.length];
        for (int i = 0; i < rgbs.length; i++) {
            RGB rgb = rgbs[i];
            red[i] = (byte) rgb.red;
            green[i] = (byte) rgb.green;
            blue[i] = (byte) rgb.blue;
        }
        if (data.transparentPixel != -1) {
            colorModel = new IndexColorModel(data.depth, rgbs.length, red, green, blue, data.transparentPixel);
        } else {
            colorModel = new IndexColorModel(data.depth, rgbs.length, red, green, blue);
        }
        BufferedImage bufferedImage = new BufferedImage(colorModel, colorModel.createCompatibleWritableRaster(data.width, data.height),
                false, null);
        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++) {
                int pixel = data.getPixel(x, y);
                pixelArray[0] = pixel;
                raster.setPixel(x, y, pixelArray);
            }
        }
        return bufferedImage;
    }
}

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;
}

公共静态缓冲区图像转换为WT（图像数据）{
ColorModel ColorModel=null；
PaletteData调色板=data.palete；
if（palete.isDirect）{
colorModel=新的DirectColorModel（data.depth、palete.redMask、palete.greenMask、palete.blueMask）；
BuffereImage BuffereImage=新的BuffereImage（colorModel，colorModel.createCompatibleWritableRaster（data.width，data.height），
假，空）；
WritableRaster raster=BuffereImage.getRaster（）；
int[]像素数组=新int[3]；
对于（int y=0；y

好的，因为我想我终于理解了您的要求，所以我决定发布一个答案。让我确定我明白了

public static void main(String[] args)
{
    Display display = Display.getDefault();
    final Shell shell = new Shell(display);
    shell.setLayout(new GridLayout(1, false));

    /* Load the image and calculate size and ratio */
    final Image image = new Image(display, "settings.png");
    final Rectangle imageSize = image.getBounds();
    final double imageRatio = 1.0 * imageSize.width / imageSize.height;

    /* Define the canvas and set the background color */
    final Canvas canvas = new Canvas(shell, SWT.BORDER);
    canvas.setBackground(display.getSystemColor(SWT.COLOR_DARK_GRAY));
    canvas.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

    canvas.addListener(SWT.Paint, new Listener()
    {
        @Override
        public void handleEvent(Event e)
        {
            Rectangle canvasSize = canvas.getBounds();

            double canvasRatio = 1.0 * canvasSize.width / canvasSize.height;

            int newHeight;
            int newWidth;

            /* Determine scaled height and width of the image */
            if (canvasRatio > imageRatio)
            {
                newWidth = (int) (imageSize.width * (1.0 * canvasSize.height / imageSize.height));
                newHeight = (int) (canvasSize.height);
            }
            else
            {
                newWidth = (int) (canvasSize.width);
                newHeight = (int) (imageSize.height * (1.0 * canvasSize.width / imageSize.width));
            }

            /* Compute position such that the image is centered in the canvas */
            int top = (int) ((canvasSize.height - newHeight) / 2.0);
            int left = (int) ((canvasSize.width - newWidth) / 2.0);

            /* Draw the image */
            e.gc.drawImage(image, 0, 0, imageSize.width, imageSize.height, left, top, newWidth, newHeight);
        }
    });

    shell.pack();
    shell.open();
    while (!shell.isDisposed())
    {
        if (!display.readAndDispatch())
            display.sleep();
    }
    display.dispose();

    /* DISPOSE THE IMAGE !!! */
    image.dispose();
}

e.gc.setAntialias(SWT.ON);
e.gc.setAdvanced(true);

Image newImage = new Image(image.getDevice(), newWidth, newHeight);
GC gc = new GC(newImage);
gc.setAdvanced(true);
gc.setAntialias(SWT.ON);
gc.drawImage(image, 0, 0, origWidth, origHeight, 0, 0, newWidth, newHeight);
gc.dispose();