How to send Screenshot to STDOUT

Question

I currently extract text from image using:

import png:- | convert png:- -units PixelsPerInch -resample 300 -sharpen 12x6.0 png:- | tesseract -l eng stdin stdout | xsel -ib

However, import png:- command to take screenshot is not working well for me. It somehow do not quite suit Linux Mint.

Is there any other command which I can use to directly send screenshot to STDOUT for further processing.

Answer 1

I remember having similar issues with scrot. In that case I added a sleep and it was fine! Worked fine for me, but I'm not on Linux Mint.

{ import png:-; sleep 0.1 ;} | convert png:- -units PixelsPerInch -resample 300 -sharpen 12x6.0 png:- | tesseract -l eng stdin stdout | xsel -ib

Also, you could try out scrot with something like:

scrot -s aoeu.png -e 'tesseract -l eng $f stdout | xsel -ib; rm -f $f'

---

A version incorporating input in comments and the answer from J. Cravens

scrot -s -f -q 100 --silent - |
    convert - -units PixelsPerInch -resample 300 -sharpen 12x6.0 - |
    tesseract -l eng stdin stdout |
    xsel -ib

Answer 2

You can use scrot with - for standard output, but it will default save a png file. Just add:

scrot -q 100 --silent - |

Should be exactly what it was looking for.

UPDATE: To do this with versions below 1.7, as it does not accept - as stdout, will be a bit more tricky. Here's a shell script:

#!/bin/bash

#Create a temp working directory
temp_dir=$(mktemp -d)
temp_file="$temp_dir/screenshot_$(date +"%Y%m%d%H%M%S").png"

#Take a screenshot to the temp file
scrot -s -f -q 100 --silent "$temp_file"

#Process the screenshot from temp
convert "$temp_file" -units PixelsPerInch -resample 300 -sharpen 12x6.0 - |
tesseract -l eng stdin stdout |
xsel -ib

#Working directory clean up
rm -r "$temp_dir"

Save it to screenshot.sh
Then, make it executable with chmod +x screenshot.sh
Finally, run ./screenshot.sh

Answer 3

KDE's spectacle screenshot tool lets you output to stdout, but only using /dev/stdout instead of -:

spectacle --background --fullscreen --output /dev/stdout

or, with short options: spectacle -bfo /dev/stdout