Understanding BufferedImage.getRGB output values

by

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 RGB components (8 bits for each) in the following format:

               2          1          0
bitpos      32109876 54321098 76543210
------   --+--------+--------+--------+
bits     ..|RRRRRRRR|GGGGGGGG|BBBBBBBB|

You can extract or set the components using bitmasks:

int color = img.getRGB(x, y);

// Components will be in the range of 0..255:
int blue = color & 0xff;
int green = (color & 0xff00) >> 8;
int red = (color & 0xff0000) >> 16;

If the color also has an alpha component (transparency) ARGB, it gets the last remaining 8 bits.

           3          2          1          0
bitpos    10987654 32109876 54321098 76543210
------   +--------+--------+--------+--------+
bits     |AAAAAAAA|RRRRRRRR|GGGGGGGG|BBBBBBBB|

And the value:

int alpha = (color & 0xff000000) >>> 24; // Note the >>> shift
                                         // required due to sign bit

An alpha value of 255 means that a color is completely opaque and a value of 0 means that the color is completely transparent.

Your color:

Your color is color = -16755216 which has:

blue : 240         // Strong blue
green:  85         // A little green mixed in
red  :   0         // No red component at all
alpha: 255         // Completely opaque

More Related Contents:

  1. How to scale a BufferedImage
  2. Rotate an image in java
  3. Java – resize image without losing quality
  4. Multi-Band Image raster to RGB
  5. How can I get the average color of an image?
  6. Generating gradients programmatically?
  7. Using Graphics2D to overlay text on a BufferedImage and return a BufferedImage
  8. refreshing background color for a row in jtable
  9. How to convert a color integer to a hex String in Android?
  10. Program freezes during Thread.sleep() and with Timer
  11. How do you clone a BufferedImage
  12. Convert each animated GIF frame to a separate BufferedImage
  13. How to draw an image over another image?
  14. Convert RGB values to Integer
  15. How to serialize an object that includes BufferedImages
  16. Java: Smooth Color Transition
  17. Java – opaque color
  18. What is the best method to capture images from a live video device for use by a Java-based application?
  19. Bufferedimage resize
  20. java.lang.IllegalArgumentException: input == null! when using ImageIO.read to load image as bufferedImage
  21. Android flood-fill algorithm [closed]
  22. Android Color Notification Icon
  23. Color fading algorithm?
  24. JFreeChart BarChart -> NO gradient
  25. Rotate a buffered image in Java
  26. How to combine multiple PNGs into one big PNG file?
  27. How do I draw an image to a JPanel or JFrame?
  28. How to compare images for similarity using java
  29. How to set SWT button foreground color?
  30. How can I import java.awt.image.BufferedImage in Android Studio

Leave a Comment