The following table shows you which correction commands and adjustment layers are available for images of different color depths and which color depths can apply commands to selections.
|
Color Depth |
Commands that Apply to |
Commands available for Selections |
Available Adjustment Layers |
|
2 color (1-bit) |
Greyscale, Negative Image |
None |
None |
|
16 color (4-bit) |
Greyscale, Posterize, Solarize, and Sepia, plus all commands on the Adjust menu |
None |
None |
|
256 color (8-bit) |
Same as 16 color (4-bit), plus the Histogram commands Equalize and Stretch |
None |
None |
|
Greyscale (8-bit) |
All commands that correct the brightness or contrast |
The same commands |
Brightness/Contrast, Curves, Invert, Levels, Posterize, Threshold |
|
16 million, 32K, or 64K color |
All correction commands |
All correction commands |
All adjustment layers |