Timeline for Pixel depth and raster output won't align with the original
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
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| Mar 18, 2019 at 23:34 | vote | accept | Overlord84 | ||
| Mar 18, 2019 at 23:34 | answer | added | Overlord84 | timeline score: 0 | |
| Mar 13, 2019 at 22:54 | history | edited | Overlord84 | CC BY-SA 4.0 |
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| Mar 13, 2019 at 11:29 | history | edited | PolyGeo♦ | CC BY-SA 4.0 |
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| Mar 13, 2019 at 7:19 | history | edited | Overlord84 | CC BY-SA 4.0 |
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| Mar 13, 2019 at 6:54 | history | edited | Overlord84 | CC BY-SA 4.0 |
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| Mar 13, 2019 at 3:30 | answer | added | crianopa | timeline score: 0 | |
| Mar 13, 2019 at 2:20 | comment | added | Michael Stimson | This will happen with reprojected rasters, the resampling is applied both at the reprojection and at the sampling (if done in Esri; how are you sampling without SA?) If you use the NEAREST resampling method the values will be closer to the original but less accurate. Alternately project your data to WGS84 and sample without resampling for the best results; it's much quicker and more accurate to project vectors than rasters. | |
| Mar 13, 2019 at 2:17 | history | edited | Overlord84 | CC BY-SA 4.0 |
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| Mar 13, 2019 at 2:15 | comment | added | Overlord84 | @MichaelStimson: I have just swapped my second step with the third. I would like to preserve the float values as much as possible and then multiply by 40. The problem is when I try and fit it into 8 Unsigned and cell size 30x30m that I tend to lose information: cells are bigger (with integer values) compared to the initial float ones and when I sample a final pixel, it encompasses and blends few smaller pixels. Is there a way around this problem? | |
| Mar 13, 2019 at 2:08 | comment | added | Michael Stimson | But are you trying to scale the values??? the input is 1 to 5.55, if you just want to multiply by 40 (40 - 200 range) then 8bit should be enough. The order of INT then Multiply is very important, are you certain you want to truncate the values before multiplication? It looks like you've done it in the reverse order (124 / 40 = 3.1). | |
| Mar 13, 2019 at 1:59 | comment | added | Michael Stimson | I take it you don't have a spatial analyst license hence the need for QGIS raster calculator. You might be better to use ArcMap to do both of the first two at the same time: set data frame CRS to GDA94 Albers, add the raster, right click on the layer and select export: CRS same as data frame, check use renderer to scale 32bit to 8bit and output but then use copy raster to change the output pixel type to UInt16 before multiplying by 40 in QGIS. | |
| Mar 13, 2019 at 0:50 | history | asked | Overlord84 | CC BY-SA 4.0 |