Starting XV:

Start the program up by typing `xv' from the unix prompt. After a short delay, the image window will appear with the default image (the XV logo, credits and revision date) displayed in it.

Click here if you wish to run XV while reading the following.

About the Image Window:

Displaying Pixel Values

Clicking (and optionally dragging) the Left mouse button inside the image window will display pixel information in the following format:

196, 137 = 191,121,209 (287 42 81 HSV)

The first pair of numbers (196,137) are the x and y positions of the cursor, in image coordinates. These numbers remain the same regardless of any image resizing, or cropping; a 320x200 image remains a 320x200 image, regardless of what size it is displayed on the screen.

Figure 1 XV Default Image Window

The first triplet of numbers (191,121,209) are the RGB values of the selected pixel. The components will have integer values in the range 0-255. The values displayed are prior to any HSV/RGB modification, but after any colormap changes.

The second triplet of numbers (287 42 81) are the HSV values of the selected pixel. The first component will have integer values in the range 0-359, and the second and third components will have integer values in the range 0-100. The values displayed are prior to any HSV/RGB modification, but after any colormap changes.

This string is automatically copied to your X server's cut buffer whenever you measure pixel values. To try this, measure a pixel's value, and then click the Middle mouse button in an xterm window.