How to use the command ppmtosixel (with examples)

The ppmtosixel command is used to convert a PPM (Portable Pixmap) image to DEC sixel format. Sixel is a bitmap graphics file format, and DEC sixel format is specifically used for printing images on DEC terminals.

Use case 1: Convert a PPM image to DEC sixel format

Code:

ppmtosixel path/to/file.ppm > path/to/file.sixel

Motivation: This use case is helpful when you want to convert a PPM image to the DEC sixel format. The converted image can then be printed or viewed on DEC terminals.

Explanation:

• ppmtosixel is the command used to convert the PPM image to DEC sixel format.
• path/to/file.ppm is the path to the input PPM image file.
• > is the output redirection operator, which redirects the output of the command to a file.
• path/to/file.sixel is the path where the converted sixel image file will be saved.

Example output: The PPM image file at path/to/file.ppm will be converted to DEC sixel format and saved as path/to/file.sixel.

Use case 2: Produce an uncompressed SIXEL file that is much slower to print

Code:

ppmtosixel -raw path/to/file.ppm > path/to/file.sixel

Motivation: By using the -raw option, the command produces an uncompressed SIXEL file that may be slower to print but ensures compatibility with terminals that do not support compressed SIXEL files.

Explanation:

• -raw is an option that instructs ppmtosixel to produce an uncompressed SIXEL file.
• path/to/file.ppm is the path to the input PPM image file.
• > is the output redirection operator, which redirects the output of the command to a file.
• path/to/file.sixel is the path where the converted sixel image file will be saved.

Example output: The PPM image file at path/to/file.ppm will be converted to an uncompressed DEC sixel format and saved as path/to/file.sixel.

Use case 3: Add a left margin of 1.5 inches

Code:

ppmtosixel -margin path/to/file.ppm > path/to/file.sixel

Motivation: Sometimes, you may want to add a left margin to the converted image, especially if you plan to print it with specific formatting requirements. This use case adds a left margin of 1.5 inches to the converted DEC sixel image.

Explanation:

• -margin is an option that specifies the margin to be added to the converted image.
• path/to/file.ppm is the path to the input PPM image file.
• > is the output redirection operator, which redirects the output of the command to a file.
• path/to/file.sixel is the path where the converted sixel image file will be saved.

Example output: The PPM image file at path/to/file.ppm will be converted to DEC sixel format with a left margin of 1.5 inches and saved as path/to/file.sixel.

Use case 4: Encode control codes in a more portable way

Code:

ppmtosixel -7bit path/to/file.ppm > path/to/file.sixel

Motivation: By default, ppmtosixel uses 8-bit control codes to encode the image data. However, some systems may only support 7-bit control codes. Using the -7bit option ensures that the image is encoded in a more portable way, although it may take up slightly more space.

Explanation:

• -7bit is an option that instructs ppmtosixel to encode the image data using 7-bit control codes.
• path/to/file.ppm is the path to the input PPM image file.
• > is the output redirection operator, which redirects the output of the command to a file.
• path/to/file.sixel is the path where the converted sixel image file will be saved.

Example output: The PPM image file at path/to/file.ppm will be converted to DEC sixel format with 7-bit control code encoding and saved as path/to/file.sixel.

Conclusion:

The ppmtosixel command is a versatile tool that allows you to convert PPM images to DEC sixel format. By using different options, you can customize the conversion process, such as adding a left margin or encoding the image data using 7-bit control codes. Whether you want to print the converted image or view it on a DEC terminal, ppmtosixel provides the necessary functionality.