I followed xehpuk’s answer but had issues with certain images having the last few rows of pixels missing when rendered in certain browsers via a data url (Chrome and Firefox, Safari seemed to render them fine). I suspect this is because the browser is doing it’s best to interpret the data but the last few … Read more
I also was trying to do the same thing, because of need to combining image processed with two libraries. And what I’ve tried to do is to put byte[] in to Mat instead of RGB value. And it worked! So what I did was: 1.Converted BufferedImage to byte array with: byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData(); … Read more
Try this: private BufferedImage createImageFromBytes(byte[] imageData) { ByteArrayInputStream bais = new ByteArrayInputStream(imageData); try { return ImageIO.read(bais); } catch (IOException e) { throw new RuntimeException(e); } }
I’m assuming that you’re running this in a servlet context. If it’s affordable to check the content type based on just the file extension, then use ServletContext#getMimeType() to get the mime type (content type). Just check if it starts with image/. String fileName = uploadedFile.getFileName(); String mimeType = getServletContext().getMimeType(fileName); if (mimeType.startsWith(“image/”)) { // It’s an … Read more
BufferedImage in = ImageIO.read(img); BufferedImage newImage = new BufferedImage( in.getWidth(), in.getHeight(), BufferedImage.TYPE_INT_ARGB); Graphics2D g = newImage.createGraphics(); g.drawImage(in, 0, 0, null); g.dispose();
Use ImageIO.read() instead: BufferedImage img = ImageIO.read(url);
No, storing a Graphics object is usually a bad idea. 🙂 Here’s why: Normally, Graphics instances are short-lived and is used to paint or draw onto some kind of surface (typically a (J)Component or a BufferedImage). It holds the state of these drawing operations, like colors, stroke, scale, rotation etc. However, it does not hold … Read more
The method drawString() uses x and y for the leftmost character’s baseline. Numbers typically have no descenders; if the same is true of text, a string drawn at position (0,0) will be rendered entirely outside the image. See this example. Addendum: You may be having trouble with an incompatible color model in your image. One … Read more
It’s a so-called mask. The thing is, you get the RGB value all in one integer, with one byte for each component. Something like 0xAARRGGBB (alpha, red, green, blue). By performing a bitwise-and with 0xFF, you keep just the last part, which is blue. For other channels, you’d use: int alpha = (rgb >>> 24) … Read more
The RGB int color contains the Red, Green, Blue components of the color in its bits. You have to look at its binary or hexadecimal representation and not look at it as a whole integer number (not look at its decimal representation). An int has 32 bits, 3×8 = 24 is used to store the … Read more