Digital Photography

sx110is.jpg I like to experiment. I'll try to keep notes about the tools (software) I use…

My camera

I bought (sept 2009) a Canon SX110IS as a replacement for my Canon A710IS (which has a nasty scratch on the lens). I know the XS120 is out, but it is not supported by CHDK yet. Besides, the 110 has a larger CCD, which might result in less image noise… I'll hang the old A710IS under my new kite 8-) The A710IS was replaced by a 2nd hand A720IS after a dive in the Maas.

Kite Aerial Photography

Zevenkamp My passion is taking aerial photographs with a camera lifted by a kite…

I keep track of my adventures on this web page, and post the images I like best on

Reclame: Een luchtfoto laten maken? dat kan!

NOTE I am in de process of moving my Kite Aerial Photography pages to a dedicated website:

OPMERKING: alle pagina's die gaan over het maken van foto's m.b.v. een vlieger worden binnenkort verhuisd naar een aparte website:

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USB Capture

On Linux, it can be done with gphoto2 (tested gphoto 2.4.7 with my Canon SX110IS)

  • power on camera
  • unmount camera 'disk'

5 frames, one every 10 seconds

  • gphoto2 -F 5 -I10 –capture-image-and-download
  • gphoto2 -F 5 -I10 –capture-image (faster, photo's stay on camera)


  • I use Gimp (the GNU Image Manipulation Program, a free Photoshop like program) to improve and manipulate the pictures I take.

The math of a camera

Want to know how a point of the world gets mapped on a pixel of jpeg? Tsai’s camera calibration method revisited gives a good mathematical description.

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Processing raw files

CHDK allows the A710IS and SX110SX to generate raw image files. I don't know yet how to process these properly with free software. I'll add notes as I go…

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Remove moving objects with a median filter

median.jpgA median filter can be used to remove moving objects from a series of images with a common background, as illustrated by this empty highway.

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“With Hugin you can assemble a mosaic of photographs into a complete immersive panorama, stitch any series of overlapping pictures and much more”. Amazing stuff!!!

Focus Stack

align_image_stack -m -a FS_ *.JPG
enfuse -o result.tif --wExposure=0 --wSaturation=0 --wContrast=1 --HardMask FS_*


I just started experimenting with HDR…

  • Hugin is able to 'do' HDR. It can create a HDR panorama (openexr file). It also does 'exposure blending'…
  • “The pfstools package is a set of command line programs for reading, writing and manipulating high-dynamic range (HDR)” Quite good (realistic) result:
align_image_stack -a A_ *.JPG -o out         # gives aligned tifs, and out.hdr
pfsin out.hdr | pfstmo_mantiuk06 |pfsout out0.tif
pfsin out.hdr | pfstmo_mantiuk06 -f 0.5 -s 1 -v |pfsout out1.tif
pfsin out.hdr | pfstmo_drago03 -b 0.8 | pfsgamma -g 1.7 |pfsout out2.tif
pfsin out.hdr | pfstmo_reinhard02 -s |pfsout out3.tif


CHDK is software that you can install on the memory of most (compact) Canon cameras. It allows you to program it (Basic and Lua), and use new or enhanced features. Great stuff! I'll keep notes...

Convert JPGs to a movie

First experiments, has to be tuned…

# list is an ascii file that lists the images
mencoder mf://@list -mf fps=1 -vf scale=640:480 -ovc lavc -lavcopts vcodec=mpeg4 -oac copy -o movie.avi
mencoder "mf://@lost" -mf fps=1 -vf scale=640:480 -o test.avi -ovc lavc -lavcopts vcodec=msmpeg4v2:vbitrate=10

Movie with embedded subtitles:

mencoder "mf://@clouds.lst" -ovc lavc -lavcopts vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=2000:keyint=15:vstrict=0:acodec=ac3 -o clouds.avi -sub "" -subfont-text-scale 3

capture a video from screen (add –full-shots for opengl stuff). xvidcap also works…

recordmydesktop  -windowid $(xwininfo |grep "Window id:"|sed -e "s/xwininfo\:\ Window id:\ // ;s/\ .*//" )

Convert video to mpg for wmp (dos)

export opt="vbitrate=2160000:mbd=2:keyint=132:vqblur=1.0:cmp=2:subcmp=2:dia=2:mv0:last_pred=3"
mencoder -ovc lavc -lavcopts vcodec=msmpeg4v2:vpass=1:$opt  -nosound -o /dev/null in.ogg 
mencoder -ovc lavc -lavcopts vcodec=msmpeg4v2:vpass=2:$opt  -nosound -o out.mpg in.ogg 
Last modified: 2010/02/18 09:22 Mijn Fijne Site hosting en design