North Auckland Line [0L]: Volume 1 Progress Update 12

Good afternoon. We have now completed mosaics for every part of the maps except for Auckland Station which is the junction at the end of the Newmarket Branch where it joins onto the NIMT. The Auckland Station maps are part of a much larger mosaic project we have been working on that has 180 layers and covers 14 km of NIMT corridor down to Westfield, which is where the North Auckland Line has its junction with the NIMT. To have the Auckland mosaic project at such a large size (the canvas needed is 34 gigapixels) with so many layers (we usually try not to exceed 100 layers in a mosaic project as a rule of thumb to prevent the file size becoming unmanageable) has only been possible by cropping mosaic layers to the minimum needed. To use an illustration, a layer that might be a 20 MB JPEG file can expand to 100 MB saved in a Gimp file, so it’s easy to see why these mosaic projects create such a challenge with their disk space usage, because we have the original JPEGs saved on another computer without creating this blowout in disk space. The full Auckland-Westfield NIMT project whilst not actually a part of Volume 1, has been done in order to be able to show the NIMT at the two junctions, and because it will also be ready for the work on the NIMT when we do Volume 2, but we appreciate that it has slowed down things with Volume 1 somewhat.

So we will be extracting tiles from the completed mosaic projects today and pushing ahead with the maps with the goal of completing the Auckland suburban area by the end of this week as previously documented.