NZ Tekonverse

  • NZ Rail Maps: Mosaic overlays and masking

    One of the useful things a good graphics package such as Gimp can do is use masks to combine layers when they overlap, so that instead of by default they overlap at their physical edges, you can mask off a part of an image so that the overlap actually is visible at the edge of…

  • Gimp resource limits

    Right now I am completing a set of maps covering from Dunedin to Mosgiel, some 17 km of rail corridor continuously mapped. The result is a Gimp file of over 60 GB in size and Gimp itself is using about 150 GB of storage (memory plus swap plus home drive cache) to allow this file…

  • NZ Rail Maps: Two different ways to cover a large area in Gimp [3]

    Last time in this series I talked about my experiments in testing whether Gimp could handle a large canvas size successfully, since this would tend to suggest a linear project for covering a long section of rail corridor (17 km in a current project) could work. If successful this might be a better way of…

  • NZ Rail Maps: Two different ways to cover a large area in Gimp [2]

    Following on from my previous post, in the case of the Dunedin-Wingatui map mosaic Gimp project, I chose to extend the size of the map canvas from 7×7 to 11×7 and bring the tiles for the Wingatui station alongside those of Green Island-Abbotsford. The reason for this was to be able to bring some smaller…

  • NZ Rail Maps: Two different ways to cover a large area in Gimp [1]

    In my last post I compared a couple of large Gimp projects I worked on. Both of these cover a significant distance and they use different ways of doing it. It is illustrative to look at those two different ways and consider if one is better than the other. The first way of doing in…

  • Webcam with Linux [1]

    We need to do some livestreaming on Facebook Live for a project I am working on. Using a phone is quick and convenient, but pretty limited unless it is a selfie. So the next option is a webcam connected to a laptop and remotely located from it by a 5 metre cable which lets me…

  • NZ Rail Maps: Gimp optimisation with SSD works well

    A few posts back in label NZ Rail Maps, I commented on how to optimise Gimp to use the swap partition on the computer effectively. I have since been able to prove using a computer with only 8 GB of RAM that it is able to use the SSD to load much bigger images without…

  • Buster challenges

    There have been a few issues I have found using Debian Buster so far. Among them Command shells have a much more limited set of commands that will work all the time. For example blkid is the latest command I have found that will not work in a Bash shell window under KDE (Konqueror). dpkg…

  • Python Scripting [4B]: Exif Based Image Renaming 2

    Today I am going to have a look at Pillow and its interface for reading EXIF data from images. As I mentioned previously, Pillow is a fork of PIL (the Python Imaging Library) and contains capabilities to read and write EXIF data from images. Although there are official documents for Pillow at Readthedocs, it is…

  • Python Scripting [4A]: Exif Based Image Renaming

    This is now a new scripting project I am starting for Python. I need this script to rename all my photos off the camera, replacing the use of IrfanView which I used on my Windows 10 computer. Whilst I still have that computer and the software, I am looking to do something with Python scripting…