Category: NZTekonverse -> Gimp
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NZ Rail Maps: Optimising Gimp and using 4x4x4 grid for mosaics [4]
Last time I posted I wrote about my experiments rescaling layers in Gimp from 0.4 metres to 0.2 metres pixel spacing and 0.3 to 0.15 metres pixel spacing and seeing how these matched with the NZR station surveys. I am still in two minds about whether to go with 0.2 metres from 0.4 metres source…
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NZ Rail Maps: Optimising Gimp and using 4x4x4 grid for mosaics [3]
Since last writing on this subject I have further determined that I can scale 0.3 and 0.4 metre pixel resolution background Linz aerial images to double the scale (0.15 and 0.2 metres) and these scales work very well with the 1:4300/4325, 1:5500 and 1:8000 scale Retrolens aerial photos which are the best ones for creating…
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NZ Rail Maps: Optimising Gimp and using 4x4x4 grid for mosaics [2]
In the previous post in this section I wrote at some length about the use of grid segmentation of Linz base layers that were at resolutions of 0.3 to 0.4 metres pixel size. The grid segmentation being used to rescale these layers to 0.1 metre pixel size and then the original grid references were assigned…
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NZ Rail Maps: Two different ways to cover a large area in Gimp [4]
Last time I wrote in this series I had been experimenting with the linear and segmented methods of covering a large geographical area in Gimp, such as I do with map mosaics for NZ Rail Maps. In summary the linear method consists of creating a large canvas that can lay out all the tiles in…
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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…
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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…
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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…
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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…
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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…
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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…