pgmedge

View documentation for the current command

$ tldr pamedge

pgmedge [options] [input_file]

-s sigma
    
Specifies the standard deviation for Gaussian smoothing prior to edge detection. A larger value applies more blurring, reducing noise but potentially blurring fine details. This is often used with Canny-like edge detectors.

-t low_threshold high_threshold
    
Sets the hysteresis thresholds for edge linking. Edges with gradient magnitudes above high_threshold are strong edges; those below low_threshold are suppressed. Edges between the two thresholds are kept only if connected to a strong edge.

-o output_file
    
Directs the output edge map to the specified PGM output_file. If not provided, the output is written to standard output.

-v
    
Enables verbose output, displaying processing steps and parameters.

-h, --help
    
Displays a help message and exits.

input_file
    
The path to the input PGM image file. If omitted, pgmedge reads from standard input.

pgmedge is a hypothetical command-line utility designed for performing edge detection on images in the Portable Graymap (PGM) format. It would typically read a PGM image from standard input or a specified file, apply an edge detection algorithm, and write the resulting edge map to standard output or an output file. Common edge detection algorithms it might employ include Sobel, Prewitt, Laplacian, or a Canny-like algorithm, often preceded by Gaussian smoothing to reduce noise. This tool would be invaluable for image analysis, computer vision, and graphics processing tasks where identifying boundaries and contours within grayscale images is crucial. Its simplicity and focus on the PGM format would allow for easy integration into shell scripts and pipelines alongside other netpbm utilities. Users could control parameters like smoothing intensity and thresholding levels to fine-tune the edge detection process for various applications, from feature extraction to object recognition.

Please note that pgmedge is not a standard, widely distributed Linux command. Its functionality and existence are inferred based on common naming conventions for image processing tools, particularly those interacting with the netpbm suite of utilities. If you encounter a script or system referencing pgmedge, it likely refers to a custom-built tool, an alias, or a component of a specialized software package.

While pgmedge itself isn't a documented standard, its concept stems from fundamental image processing tasks. Edge detection algorithms like Sobel, Prewitt, and Canny have been cornerstones of computer vision since the 1960s and 70s. Tools for applying these algorithms, often within the netpbm framework (first released in the late 1980s as pbmplus), have been essential for researchers and developers. A command named pgmedge would fit neatly into this legacy, representing a specialized tool for a common image analysis need, potentially developed as a custom script or a niche addition to existing libraries.

pnm(5), pgmtopgm(1), pnmsmooth(1), pamedge(1)