1

I have set up recently almost autonomous bolid (falling star) and satellite flare detector using RPi3 and NoIR v2. I have been using for some time Meteotux, which is really great but after recent updates it creates artifacts and only few times are possible (500 ms, 4s and 6s) because rest of them are causing memory fragmentation. Meteotux is not open-source software and was abandoned some time ago. I have tried to contact the responsible person but without luck. I have also tried to use multiple raspistill command variations together with raspiuyv and script it python. Problem is that nothing besides raspistill can give me what I want - a software which records pictures at desired exposure time, in burst mode (no delay between pictures) and in timelapse with elevated ISO settings. Somehow person responsible for meteotux bypassed all the problems related to recording with raspberry camera. Has anyone have a clue if reverse engineering of binary meteotux_pi file is possible or if there is any open source software which can do the same things? I would be very grateful for the answer!

Cheers, Dawidstar trails made with meteotux_pi

  • Hello and welcome. I think image stacking is a way to go - it pushes the whole issue to post-processing leaving the raspistill in a "simple" picture taking mode that should not trouble you. – Ghanima Mar 29 '17 at 20:10
2

Capturing the images

I use this command to capture long exposure night shots...

raspistill -bm -tl 1000 -v -set -ISO 800 -awb off -awbg 1,1 -t 21600000 -ss 6000000 -o sky/%06d.jpg

That generates lots of individual jpg files, but a bunch of frames get skipped due to processing time so the numbering sequence is out of kilter.


Fixing the numbering sequence

For easy post-processing you need to fix the file name numbering sequence. I that with this...

I=0 
for F in 0*.jpg; do 
  echo "$F" `printf image_%06d.jpg $I` 
  mv "$F" `printf image_%06d.jpg $I` 2>/dev/null || true 
  I=$((I + 1)) 
done

Post processing

In order to get the star trail effect i use convert from the imagemagick package which allows you to stack the images on top of one another and thus create the star trail effect. The script looks like this ...

#!/bin/bash

cp sky/000000.jpg /tmp 
for f in `ls sky/*.jpg` 
do 
    echo $f
    convert /tmp/000000.jpg $f -gravity center -compose lighten -composite -format jpg /tmp/000000.jpg 
done
cp /tmp/000000.jpg star-trail-composite-$(date "+%Y%m%d-%H%M%S").jpg

Bonus material

As well as stacking the images to produce a composite (star trail), you can combine them into a movie. To do that you use avconv from the libav-tools package. Here's the command...

avconv -i sky/%06d.jpg -r 5 -vf scale=1280:720 -vcodec libx264 -r 5 star-trail-movie-$(date "+%Y%m%d-%H%M%S").mp4
  • yes, I am familiar with raspistill command with burst mode (-bm) and timelapse (-tl). But still pictures are not recorded every 6s - sometimes command skips recording and causes breaks in the recording. – Dawid Mar 30 '17 at 21:30
0

Regarding pictures processing I have developed another script which allows conversion of pictures:

x=$(ls -tr 2017* | head -1)
cp $x /tmp
echo 'Set the picture maximum brightness: 0 - 255 (recommended ~200)'
read brightness
brightfor=$[brightness*4]
for f in `ls *.jpg`
    do
        LIGHT=$(identify -verbose $f | awk -F. '/mean/{gsub("mean:",""); print $1}' | head -4)
        LIGHT1=$(echo $LIGHT | awk '{count++; col1 += $1; col2 += $2; col3 += $3; col4 += $4; print ($1+$2+$3+$4)}')
         if [[ $LIGHT1 -lt $brightfor ]] && [[ $LIGHT1 -gt 25 ]];
            then
             convert /tmp/$x $f -gravity center -compose lighten -composite -format jpg /tmp/$x #
             echo $f 'Picture is ok and is converted!' $[LIGHT1/4]
            else
             echo $f 'Picture is too bright!' $[LIGHT1/4]
            fi
    done
mv /tmp/$x /home/converted-$x

for movies I use:

#!/bin/bash
cat *.jpg | ffmpeg -f image2pipe -framerate 20 -vcodec mjpeg -i - -vcodec libx264 -crf 25 $(date +%Y%m%d).mp4

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.