pngcheck:tldr:a6016

The command "pngcheck -cvt ${image-png}" is used to check the validity of a PNG image file.

Here is a breakdown of the command:

• "pngcheck": This is the name of the command-line tool used to check PNG files.
• "-cvt": This is an option used with pngcheck to trigger a format conversion if necessary.
• "${image-png}": This is a placeholder for the file path or name of the PNG image file that you want to check. It should be replaced with the actual path or name of the PNG image file you are checking.

By running this command, you can examine the PNG file for various issues such as structural integrity, CRC (cyclic redundancy check) errors, PNG specific errors, and chunk inconsistencies. The "-cvt" option additionally allows the conversion of a PNG file to a different format if the file has unsupported features or problems.