pngdat.1

.TH pngdat "1" "April 2023" "pngdat" "General Commands Manual"
.SH NAME
pngdat \- put data into or extract data from a png
.SH SYNOPSIS
.B pngdat
\fI\,OPTION\/\fR \fI\,FILE\/\fR \fI\,FILE\/\fR
.SH DESCRIPTION
.\" Add any additional description here
.PP
pngdat takes a file of any kind and converts it into png.  It is as if one
were to prepend a png header to any file.  The identical effect can be
achieved by importing into Gimp as raw RGB 24 data and then exporting as 
png, but this is easier since it handles things like calculating the output
png dimensions.
.PP
pngdat can also extract said data from the png.
.PP
Input png files must not be progressive. One of two possible options must be
specified before the two file names.
.PP
.TP
\fB\-e\fR
Encode the first file and create a png as the second file.  Extra zero bytes
will be added to fit into the png's pixel dimensions.
.TP
\fB\-d\fR
Read and decode the first file, containing data inside a valid 24-bit
non-progressive png file, and output the original data, usually with extra
zero bytes on the end.  Some formats, notable among them tar, are forgiving of
such end padding.

.SH AUTHOR
Peter C. Capasso

.SH COPYRIGHT
Copyright \(co 2023 Peter C. Capasso, released under the MIT Expat
License.

.SH SEE ALSO
.B png
(5)
.
.br