Linux command
pamstretch 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
Stretch an image 2x in both dimensions
pamstretch [2] [input.pam] > [output.pam]
Stretch 3x and drop the extra edge pixel
pamstretch -dropedge [3] [input.pam] > [output.pam]
Stretch horizontally only
pamstretch -xscale=[4] -yscale=[1] [input.pam] > [output.pam]
Stretch vertically only
pamstretch -xscale=[1] -yscale=[2] [input.pam] > [output.pam]
Interpolate to black
pamstretch -blackedge [2] [input.pam] > [output.pam]
Stretch from standard input
cat [input.pnm] | pamstretch [2] > [output.pnm]
说明
pamstretch scales up a PAM, PNM, PPM, PGM, or PBM image by integer factors, interpolating between neighboring source pixels rather than simply replicating them. This yields smoother results than plain pixel duplication for photographs and other continuous-tone images. The tool supports independent horizontal and vertical factors through -xscale and -yscale, or a single uniform factor given as the final positional argument. Edge behaviour is configurable: by default extra pixels are synthesised, -blackedge fades to black, and -dropedge trims the trailing row and column.
参数
- -xscale=_X_
- Integer horizontal scale factor (default 1 if only -yscale is given).
- -yscale=_Y_
- Integer vertical scale factor (default 1 if only -xscale is given).
- -blackedge
- Interpolate toward black at the right and bottom edges, preserving output dimensions.
- -dropedge
- Drop one source pixel at the right and bottom edges. Produces a cleaner result but yields non-standard output dimensions (_width_ * _N_ - _N_ + 1).
FAQ
What is the pamstretch command used for?
pamstretch scales up a PAM, PNM, PPM, PGM, or PBM image by integer factors, interpolating between neighboring source pixels rather than simply replicating them. This yields smoother results than plain pixel duplication for photographs and other continuous-tone images. The tool supports independent horizontal and vertical factors through -xscale and -yscale, or a single uniform factor given as the final positional argument. Edge behaviour is configurable: by default extra pixels are synthesised, -blackedge fades to black, and -dropedge trims the trailing row and column.
How do I run a basic pamstretch example?
Run `pamstretch [2] [input.pam] > [output.pam]` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does -xscale=_X_ do in pamstretch?
Integer horizontal scale factor (default 1 if only -yscale is given).