Java，在Java中调整文件大小后图像变黑

在Java中调整多部分文件的大小后，图像变为黑色

我正在尝试将文件保存在sql db中。。由于内存原因，我需要降低图像质量和大小。调整大小后，图像变黑

有什么想法吗

private static int IMG_HEIGHT = 1280;
private static int IMG_WIDTH= 860;
private static int imgType = Image.SCALE_SMOOTH;

try {
        byteArr = doc.getBytes();
        ImageIcon imgIcon = new ImageIcon(byteArr);

        int height = imgIcon.getIconHeight();
        int width  = imgIcon.getIconWidth();

        if(height > IMG_HEIGHT || width > IMG_WIDTH){

            int newWidth = width;
            int newHeight = height;

            if(height > IMG_HEIGHT){
                newHeight = IMG_HEIGHT;
            }

            if(width > IMG_WIDTH){
                newWidth = IMG_WIDTH;
            }

            System.out.println("Img newHeight = "+newHeight);
            System.out.println("Img newWidth = "+newWidth);

            Image newImage = imgIcon.getImage();
            newImage = newImage.getScaledInstance(newWidth, newHeight, imgType);

            BufferedImage buffImage = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_RGB);
            Graphics2D g2 = buffImage.createGraphics();
            g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
            g2.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
            g2.drawImage(newImage, 0, 0, width, height, null);

    //      g2.setColor(Color.WHITE);
    //      g2.fillRect(0, 0, newWidth, newHeight);
    //      g2.setComposite(AlphaComposite.SrcOver);

    //      AffineTransform scaleTransform = AffineTransform.getScaleInstance(width / (double) newImage.getWidth(null), height / (double) newImage.getHeight(null));
    //      g2.drawImage(newImage, scaleTransform, null);
            g2.dispose();   

            baos = new ByteArrayOutputStream();

            ImageIO.write(buffImage,"jpg", baos);

---

我对透明背景的图像也有类似的问题。 只需将

graphics.drawImage

中的

Color.WHITE

作为背景色，就可以避免黑色背景

    Graphics2D graphics = buffImage.createGraphics();
    graphics.drawImage(newImage, 0, 0, IMAGE_WIDTH, IMAGE_HEIGHT, Color.WHITE, null);
    graphics.setComposite(AlphaComposite.getInstance(AlphaComposite.DST_IN, 1.0f));

---

我使用了Scalr库，它只用一行就解决了我的问题：）

---

bImageFromConvert是BuffereImage…

感谢您的回复，但它不会改变任何事情：（嗨，四年前，您找到了解决这个问题的方法吗？

BufferedImage thumbS = Scalr.resize(bImageFromConvert, Scalr.Method.BALANCED, IMG_HEIGHT, IMG_WIDTH, Scalr.OP_ANTIALIAS);