Java BufferedImage to PNG format Base64 String

by

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 bytes of data was missing so it shows what it can.

The wrapping of the output stream seems to be the cause of this problem. The documentation for Base64.wrap(OutputStream os) explains:

It is recommended to promptly close the returned output stream after use, during which it will flush all possible leftover bytes to the underlying output stream.

So depending on the length of the data, it’s possible the last few bytes are not flushed from the stream because close() isn’t called on it. My solution to this was to not bother wrapping the stream and just encode the stream directly:

public static String imgToBase64String(final RenderedImage img, final String formatName)
{
  final ByteArrayOutputStream os = new ByteArrayOutputStream();

  try
  {
    ImageIO.write(img, formatName, os);
    return Base64.getEncoder().encodeToString(os.toByteArray());
  }
  catch (final IOException ioe)
  {
    throw new UncheckedIOException(ioe);
  }
}

This resolved the issues with the missing rows of pixels when rendered in a browser.

More Related Contents:

  1. Exporting a JPanel to an image
  2. Decode Base64 data in Java
  3. Java – get pixel array from image
  4. Using Graphics2D to overlay text on a BufferedImage and return a BufferedImage
  5. Program freezes during Thread.sleep() and with Timer
  6. How do you clone a BufferedImage
  7. How to setSize of image using RescaleOp
  8. Convert each animated GIF frame to a separate BufferedImage
  9. How to make a color transparent in a BufferedImage and save as PNG
  10. How to draw an image over another image?
  11. Rotate BufferedImage Inside JPanel
  12. Convert RGB values to Integer
  13. Base64 encoder and decoder
  14. How to serialize an object that includes BufferedImages
  15. Rotate an image in java
  16. Range of valid character for a base 64 encoding
  17. Bufferedimage resize
  18. java.lang.IllegalArgumentException: input == null! when using ImageIO.read to load image as bufferedImage
  19. Storing UUID as base64 String
  20. Java – resize image without losing quality
  21. Rotate a buffered image in Java
  22. How to combine multiple PNGs into one big PNG file?
  23. How do I draw an image to a JPanel or JFrame?
  24. Write Base64-encoded image to file
  25. Understanding BufferedImage.getRGB output values
  26. Convert a Graphics2D to an Image or BufferedImage
  27. Java Encode file to Base64 string To match with other encoded string
  28. how to convert hex to base64
  29. How can I import java.awt.image.BufferedImage in Android Studio
  30. How/Can I use base64 as image source in a Jasper Report template?

Leave a Comment