Linux command
pnmnlfilt 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
Smooth noise
pnmnlfilt [0.4] [0.8] [input.pnm] > [output.pnm]
Optimal estimation smoothing
pnmnlfilt [1.2] [1.0] [input.pnm] > [output.pnm]
Edge enhancement
pnmnlfilt [-0.3] [0.8] [input.pnm] > [output.pnm]
说明
pnmnlfilt applies a non-linear filter to a PNM image, combining noise reduction with edge preservation. The single alpha parameter selects between three distinct modes: alpha-trimmed mean filter for smoothing and noise reduction (alpha 0.0-0.5), optimal estimation smoothing that adapts to local variance (alpha 1.0-2.0), and edge enhancement that sharpens transitions (negative alpha). The radius parameter controls the hexagonal pixel neighborhood size. Larger radii produce stronger effect but may blur fine details. Unlike simple convolution filters, pnmnlfilt avoids destroying sharp edges during smoothing.
FAQ
What is the pnmnlfilt command used for?
pnmnlfilt applies a non-linear filter to a PNM image, combining noise reduction with edge preservation. The single alpha parameter selects between three distinct modes: alpha-trimmed mean filter for smoothing and noise reduction (alpha 0.0-0.5), optimal estimation smoothing that adapts to local variance (alpha 1.0-2.0), and edge enhancement that sharpens transitions (negative alpha). The radius parameter controls the hexagonal pixel neighborhood size. Larger radii produce stronger effect but may blur fine details. Unlike simple convolution filters, pnmnlfilt avoids destroying sharp edges during smoothing.
How do I run a basic pnmnlfilt example?
Run `pnmnlfilt [0.4] [0.8] [input.pnm] > [output.pnm]` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
Where can I find more pnmnlfilt examples?
This page includes 3 examples for pnmnlfilt, plus related commands for nearby Linux tasks.