Linux command
pnmgamma 命令
文本
涉及管道、覆盖或删除，执行前请先确认路径和参数。
常用示例
Apply gamma correction
pnmgamma [gamma] [input.pnm] > [output.pnm]
Brighten image
pnmgamma 2.2 [input.pnm] > [output.pnm]
Darken image
pnmgamma 0.5 [input.pnm] > [output.pnm]
Per-channel gamma
pnmgamma [r_gamma] [g_gamma] [b_gamma] [input.pnm] > [output.pnm]
说明
pnmgamma applies gamma correction to PNM images, adjusting the brightness curve by raising each pixel value to a power function. Values greater than 1 brighten the image while values less than 1 darken it. Per-channel gamma values can be specified separately for red, green, and blue. The -ungamma option reverses a previously applied gamma correction. Part of the Netpbm toolkit; superseded by pamgamma.
参数
- -ungamma
- Remove gamma correction.
- -cieramp
- Use CIE luminance ramp.
FAQ
What is the pnmgamma command used for?
pnmgamma applies gamma correction to PNM images, adjusting the brightness curve by raising each pixel value to a power function. Values greater than 1 brighten the image while values less than 1 darken it. Per-channel gamma values can be specified separately for red, green, and blue. The -ungamma option reverses a previously applied gamma correction. Part of the Netpbm toolkit; superseded by pamgamma.
How do I run a basic pnmgamma example?
Run `pnmgamma [gamma] [input.pnm] > [output.pnm]` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does -ungamma do in pnmgamma?
Remove gamma correction.