Convert tif image with transparent background causes, black background Java Jai

Question

I trying convert an image in tiff format with background transparent, to jpeg to resize to 200x200 or 1200x1200, but when convert, the background turn to black, i want keep the background transparent or white after conversion

My code is following:

public static void TiffToJpg(String tiff, String output) throws IOException {
        File tiffFile = new File(tiff);
        SeekableStream s = new FileSeekableStream(tiffFile);
        TIFFDecodeParam param = null;
        ImageDecoder dec = ImageCodec.createImageDecoder("tiff", s, param);
        RenderedImage op = dec.decodeAsRenderedImage(0);
        FileOutputStream fos = new FileOutputStream(output);

        JPEGEncodeParam jpgparam = new JPEGEncodeParam();
        jpgparam.setQuality(100);
        ImageEncoder en = ImageCodec.createImageEncoder("jpeg", fos, jpgparam);
        en.encode(op);

        BufferedImage in = javax.imageio.ImageIO.read(new java.io.File("oi.jpg"));

        BufferedImage out = scaleImage(in, BufferedImage.TYPE_INT_RGB, 200, 200);
        javax.imageio.ImageIO.write(out, "JPG", new java.io.File("thumbnail.jpg"));

        BufferedImage out2 = scaleImage(in, BufferedImage.TYPE_INT_RGB, 1200, 1200);
        javax.imageio.ImageIO.write(out2, "JPG", new java.io.File("web-image.jpg"));

        fos.flush();
        fos.close();
    }

    public static void main(String[] args) throws Exception {
        Tiffthumbs.TiffToJpg("oi.tif", "oi.jpg");
    }

    public static BufferedImage scaleImage(BufferedImage image, int imageType, int newWidth, int newHeight) {
        // Make sure the aspect ratio is maintained, so the image is not distorted
        double thumbRatio = (double) newWidth / (double) newHeight;
        int imageWidth = image.getWidth(null);
        int imageHeight = image.getHeight(null);
        double aspectRatio = (double) imageWidth / (double) imageHeight;

        if (thumbRatio < aspectRatio) {
            newHeight = (int) (newWidth / aspectRatio);
        } else {
            newWidth = (int) (newHeight * aspectRatio);
        }

        // Draw the scaled image
        BufferedImage newImage = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_3BYTE_BGR);
        Graphics2D graphics2D = newImage.createGraphics();
        graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        graphics2D.drawImage(image, 0, 0, newWidth, newHeight, null);

        return newImage;
    }

How do this in java JAI?

Does JPG support transparency? `BufferedImage.TYPE_INT_RGB` creates a non-transparent `BufferedImage`. *"or white after conversion"* then fill the target image with a white color before painting the master image — MadProgrammer, Jun 25 '18 at 00:32

score 0 · Answer 1 · answered Jun 25 '18 at 01:48

Change the scale image function to below piece of code and it should work. What it is doing that it is just repainting the complete image with white color before painting the actual image:

public static BufferedImage scaleImage(BufferedImage image, int imageType, int newWidth, int newHeight) {
        // Make sure the aspect ratio is maintained, so the image is not distorted
        double thumbRatio = (double) newWidth / (double) newHeight;
        int imageWidth = image.getWidth(null);
        int imageHeight = image.getHeight(null);
        double aspectRatio = (double) imageWidth / (double) imageHeight;

        if (thumbRatio < aspectRatio) {
            newHeight = (int) (newWidth / aspectRatio);
        } else {
            newWidth = (int) (newHeight * aspectRatio);
        }

        // Draw the scaled image
        BufferedImage newImage = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_3BYTE_BGR);
        Graphics2D graphics2D = newImage.createGraphics();
        graphics2D.setColor(Color.WHITE);
        graphics2D.fillRect(0, 0, newWidth, newHeight);
        graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        graphics2D.drawImage(image, 0, 0, newWidth, newHeight, null);

        return newImage;
    }

Without change:

After change:

works fine, do you know how i keep the same quality of image? — Mister B, Jun 25 '18 at 12:12
@MisterB As you have reduced the size of the image, hence you will loose the quality — Aman Chhabra, Jun 25 '18 at 15:57

Convert tif image with transparent background causes, black background Java Jai

1 Answers1