Routines (alphabetical) > Routines: G > GAMMA_CT

# GAMMA_CT

The GAMMA_CT procedure applies gamma correction to a color table.

This routine is written in the IDL language. Its source code can be found in the file `gamma_ct.pro` in the `lib` subdirectory of the IDL distribution.

## Syntax

GAMMA_CT, Gamma [, /CURRENT] [, /INTENSITY]

## Arguments

### Gamma

The value of gamma correction. A value of 1.0 indicates a linear ramp (i.e., no gamma correction). Higher values of Gamma give more contrast. Values less than 1.0 yield lower contrast.

## Keywords

### CURRENT

Set this keyword to apply correction from the “current” color table (i.e., the values R_CURR, G_CURR, and B_CURR in the COLORS common block). Otherwise, correction is applied from the “original” color table (i.e., the values R_ORIG, G_ORIG, and B_ORIG in the COLORS common block). The gamma corrected color table is always saved in the “current” table (R_CURR, G_CURR, B_CURR) and the new table is loaded.

### INTENSITY

Set this keyword to correct the individual intensities of each color in the colortable. Otherwise, the colors are shifted according to the gamma function.

## Version History

Pre 4.0 | Introduced

## See Also

PSEUDO, STRETCH