Updated batch-cropping script

By far the most popular post on this blog has been “How to batch separate & crop multiple scanned photos” (click to link to original post). Thank you for your support, everyone!


While the script seems to have worked pretty well for most of you for the past three (!) years, there was actually a bit of a bug in it, making it not work for non-white backgrounds. This is now fixed!

In addition to fixing the bug, I’ve added a few new features including

  • Ability to set output JPEG quality
  • Setting a base name manually
  • Manually selecting the background colour (in case the auto-selection doesn’t work as it should)
  • The ability to automatically save output to the source directory

I hope you enjoy this new and improved script, which can be downloaded by clicking on the following link: DivideScannedImages_improved_v2.zip.

Instructions for installing and using this script are identical as for the original one (click here to see the original instructions, under the “Gimp”heading).

Here is a screenshot of the new and improved DivideScannedImages script’s user interface:




Left: RGB = (205,204,209)
Right: RGB = (116,134,210)

Blue Steam

As a photographer I see my camera as a tool with which to capture and create. As an engineer, I see my camera as a wonderful machine and opto-electric toy. But sometimes a situation arises that makes a camera into a scientific tool. To make visible some hidden property of reality itself.

After this poetic introduction, it might seem a little mundane to tell you that this post is about the steam the comes out of my coffee machine. And in fact you don’t even need a camera – this is something that you can see with your naked eye. We own a Delonghi Icona home espresso machine, which looks like this:
DeLonghi_IconaLike most machines of this type it has a milk frother side-arm (on the right), that can be used for making cappuccinos. It works by forcing hot steam out at high velocity. The steam’s velocity is controlled by a valve which one opens by turning the round black knob on top.

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How to photograph the Aurora Borealis

This year (2013-2014) is a good time for seeing the Aurora Borealis (and its lesser-known Southern twin, the Aurora Australis) – commonly known as the Northern- and Southern Lights. I have my heart set on seeing the Lights with my own eyes in the coming year, so in this post I’d like to talk about how one can best prepare for capturing this natural wonder.

A friend, Bart Vastenhouw, travelled to the region of Varanger in Norway to see and photograph the lights. Here is one of the photographs he came back with:Aurora at Varanger

Bart captured this beautiful scene using a Canon 40D and Canon 10-22mm F3.5-4.5 wide-angle lens. The 40D was a good camera, but these days there are better ones to choose from. The lens is decent too, but for best results you’d want a wide angle with larger aperture (F2.8 or faster).

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New firmware fixes D600 HDMI output. (Also, updates for almost all of Nikon’s current other DSLRs)

Yesterday, Nikon released new firmware for almost all of its current DSLR line-up, namely for the D4, D800, D600, D3, D3s, D3x, D7000 and D3200. Most of these updates only add full compatibility to the exotic new 800mm f/5.6E FL ED VR lens – a lens very few people will ever see or use.


The highlight, for me, is the fact that Nikon has now finally addressed the uncompressed HDMI bug that frustrated D600 videographers. This issue used to be a reason for DSLR videographers to get the more expensive D800, and seemed like a lame up-selling scam on Nikon’s part. No more, it seems!

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How to batch separate & crop multiple scanned photos

In this post I’ll show you two ways in which you can automatically split a (collection of) scanned pages, each containing several photos, into individual image files. My experience is that for this GIMP works better than Photoshop, and as an added bonus: it’s free!

Caveat: The “deskew” operation in the GIMP script only works on Windows computers due to its dependence on “deskew.exe”. If you use Apple or Linux this step will be silently skipped, and the rest of the script will work.

[2013-05-16 Update: the GIMP script can now handle TIF files as well]
[2014-10-02 Handles reading .tiff and .jpeg extensions too. Output dpi set to 600.]
[2016-02-14 The GIMP script has been revamped, with new functions as well as a bugfix for non-white backgrounds. Works for all OS’es!]


Just like you, I also have old photo albums at home. Albums with family photographs, glued to paperboard pages. And you also probably want to have them in digital format – e.g. to share with family members, to protect them from degradation and loss, or just for your digital library.

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