raspi2png

Utility to take a snapshot of the raspberry pi screen and save it as a PNG file. Works with all Raspberry Pi boards.

Usage: raspi2png [--pngname name] [--width <width>] [--height <height>] [--compression <level>] [--delay <delay>] [--display <number>] [--stdout] [--version] [--help]

--pngname,-p - name of png file to create (default is snapshot.png)
--height,-h - image height (default is screen height)
--width,-w - image width (default is screen width)
--compression,-c - PNG compression level (0 - 9)
--delay,-d - delay in seconds (default 0)
--display,-D - Raspberry Pi display number (default 0)
--stdout,-s - write file to stdout
--savepath,-a - save path
--version,-v - print version number
--help,-H - print this usage information

Simple Install

Run this command through terminal or CLI screen.

curl -sL https://raw.githubusercontent.com/GrazerComputerClub/raspi2png/master/installer.sh | bash -

Manual Building

You will need to install libpng before you build the program. On Raspbian / Raspberry Pi OS execute
sudo apt-get install libpng-dev
Then just type 'make' and 'make install' in the raspi2png directory you cloned from github.

Execute with print key (triggerhappy)

create configuration file '/etc/triggerhappy/triggers.d/printscr.conf':

KEY_SYSRQ	1	/usr/bin/raspi2png -a /home/pi/snapshot

execute following commands:

mkdir /home/pi/snapshot
chmod g+w /home/pi/snapshot 
sudo chown nobody /home/pi/snapshot
sudo adduser nobody video
sudo service triggerhappy restart

Hardware GPIO input for print key (BCM26 active low)

Command-line:

sudo dtoverlay gpio-key gpio=26 keycode=99 label="KEY_SYSRQ" gpio_pull=2

config.txt:

dtoverlay=gpio-key,gpio=26,keycode=99,label="KEY_SYSRQ",gpio_pull=2

Benchmark

raspi2png 1.1, 720p screen, Raspberry Pi 3 B, RAM-disk

compression	seconds	size (KiB)
0	0,23	2705
1	0,42	676
2	0,42	654
3	0,53	624
4	0,57	606
5	0,71	593
6	1,10	575
7	1,46	569
8	3,04	564
9	5,30	560

optipng size: ~553 KiB