How to use the command 'pnmtorast' (with examples)
The ‘pnmtorast’ command is a tool used to convert PNM files (Portable anymap format) to Sun rasterfiles. It is a part of the netpbm package, which provides a collection of portable pixmap utilities. The convert command takes an input PNM file and outputs a Sun rasterfile.
Use case 1: Convert a PNM image to a RAST image
Code:
pnmtorast path/to/input.pnm > path/to/output.rast
Motivation: In some cases, the PNM format might not be compatible with certain applications or systems. By converting the PNM image to a RAST image, it can be easily used in systems that require this format.
Explanation: The ‘pnmtorast’ command takes an input PNM file specified by path/to/input.pnm and converts it to a RAST image. The output is redirected to path/to/output.rast.
Example output: If the input PNM image is successfully converted to a RAST image, there will be no output displayed in the terminal. The converted RAST image will be saved at the specified output path.
Use case 2: Force either RT_STANDARD or RT_BYTE_ENCODED form for the output
Code:
pnmtorast -standard|rle path/to/input.pnm > path/to/output.rast
Motivation: By default, ‘pnmtorast’ will automatically select the output format based on the input image. However, in some cases, it may be necessary to explicitly specify the output format as either RT_STANDARD or RT_BYTE_ENCODED for specific applications or compatibility requirements.
Explanation: The ‘-standard’ and ‘-rle’ options are used to force either RT_STANDARD or RT_BYTE_ENCODED form for the output, respectively. The ‘-standard’ option specifies the output format as RT_STANDARD, while the ‘-rle’ option specifies the output format as RT_BYTE_ENCODED. The input PNM file is specified by path/to/input.pnm. The converted RAST image is then redirected to path/to/output.rast.
Example output: If the input PNM image is successfully converted to the specified output format, there will be no output displayed in the terminal. The converted RAST image will be saved at the specified output path.
Conclusion:
The ‘pnmtorast’ command is a useful tool for converting PNM files to Sun rasterfiles. It provides flexibility in terms of output format selection and allows for compatibility with different systems and applications. Whether you need to convert a PNM image to a RAST image or force a specific output format, the ‘pnmtorast’ command has you covered.
