Why QGIS produces georeferenced TIFF files differing in size by two orders of magnitude on the basis of very similar JPEG maps?
Clash Royale CLAN TAG#URR8PPP
I am using QGIS for vectorising some small-scale maps from a historical atlas. The maps are provided as JPEG images 3703 x 4718 ranging roughly from 5 to 9 MB in size. All georeferenced tiff images are roughly from 40 to 100 MB. But one. One of the maps, which is by no means remarkable and processed in exactly the same manner as the others results in a 5+ GB TIFF file which is nearly unmanageable.
What may be the cause of that?
Software details: QGIS 3.4.2-Madeira under Ubuntu 16.04.
Source image is imported as: "Unknown datum based on Bessel 1841 ellipsoid".
Transformation settings are: "Transformation type: Thin Plate Spline / Resampling method : Cubic / Target SRS: EPSG:4326 - WGS 84 / Compression: none"
qgis georeferencing
edited Dec 14 at 22:07
PolyGeo♦
53.1k1779238
asked Dec 14 at 20:49
Alexei Kouprianov
362
add a comment |
I am using QGIS for vectorising some small-scale maps from a historical atlas. The maps are provided as JPEG images 3703 x 4718 ranging roughly from 5 to 9 MB in size. All georeferenced tiff images are roughly from 40 to 100 MB. But one. One of the maps, which is by no means remarkable and processed in exactly the same manner as the others results in a 5+ GB TIFF file which is nearly unmanageable.
What may be the cause of that?
Software details: QGIS 3.4.2-Madeira under Ubuntu 16.04.
Source image is imported as: "Unknown datum based on Bessel 1841 ellipsoid".
Transformation settings are: "Transformation type: Thin Plate Spline / Resampling method : Cubic / Target SRS: EPSG:4326 - WGS 84 / Compression: none"
qgis georeferencing
edited Dec 14 at 22:07
PolyGeo♦
53.1k1779238
asked Dec 14 at 20:49
Alexei Kouprianov
362
add a comment |
I am using QGIS for vectorising some small-scale maps from a historical atlas. The maps are provided as JPEG images 3703 x 4718 ranging roughly from 5 to 9 MB in size. All georeferenced tiff images are roughly from 40 to 100 MB. But one. One of the maps, which is by no means remarkable and processed in exactly the same manner as the others results in a 5+ GB TIFF file which is nearly unmanageable.
What may be the cause of that?
Software details: QGIS 3.4.2-Madeira under Ubuntu 16.04.
Source image is imported as: "Unknown datum based on Bessel 1841 ellipsoid".
Transformation settings are: "Transformation type: Thin Plate Spline / Resampling method : Cubic / Target SRS: EPSG:4326 - WGS 84 / Compression: none"
qgis georeferencing
edited Dec 14 at 22:07
PolyGeo♦
53.1k1779238
asked Dec 14 at 20:49
Alexei Kouprianov
362
I am using QGIS for vectorising some small-scale maps from a historical atlas. The maps are provided as JPEG images 3703 x 4718 ranging roughly from 5 to 9 MB in size. All georeferenced tiff images are roughly from 40 to 100 MB. But one. One of the maps, which is by no means remarkable and processed in exactly the same manner as the others results in a 5+ GB TIFF file which is nearly unmanageable.
What may be the cause of that?
Software details: QGIS 3.4.2-Madeira under Ubuntu 16.04.
Source image is imported as: "Unknown datum based on Bessel 1841 ellipsoid".
Transformation settings are: "Transformation type: Thin Plate Spline / Resampling method : Cubic / Target SRS: EPSG:4326 - WGS 84 / Compression: none"
qgis georeferencing
qgis georeferencing
edited Dec 14 at 22:07
PolyGeo♦
53.1k1779238
asked Dec 14 at 20:49
Alexei Kouprianov
362
edited Dec 14 at 22:07
PolyGeo♦
53.1k1779238
asked Dec 14 at 20:49
Alexei Kouprianov
362
edited Dec 14 at 22:07
PolyGeo♦
53.1k1779238
edited Dec 14 at 22:07
PolyGeo♦
53.1k1779238
edited Dec 14 at 22:07
PolyGeo♦
53.1k1779238
53.1k1779238
asked Dec 14 at 20:49
Alexei Kouprianov
362
asked Dec 14 at 20:49
Alexei Kouprianov
362
asked Dec 14 at 20:49
Alexei Kouprianov
362
362
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
By default I don't believe QGIS applies and type of lossy or lossless compression to exported images.
When you are ready to export the georeferenced image, there are some options available to begin compressing the images.
There is the compression option but seems a little limited and offers 4 options:
- none
- LZW
- Packbits
- Deflate
But it might be better to choose something like None, which will result in a large file, but this is a scratch dataset that you can consider disposing of if the next step is successful!
With the new large tiff in QGIS. You can right-click it and choose Export > Save As...
That opens the Save raster layer as... window and in there look for Create Options and place a checkmark there.
This will enable the profile settings which have some sane defaults like High Compression which I think is lossless and JPEG Compression which might be lossy.
Another culprit for the single tiff you have being so large is that it's extent is rather large and could be filling in with nodata or some other value.
answered Dec 14 at 21:09
SaultDon
7,73812561
The export parameters are the same for all files, I use "Compression: none" very consistently. Geometry of the neighbouring file is nearly the same (there are corners filled with black, but they are of similar proportions to those in other files). For some unknown reason, however, the smaller neighbour is converted to a 6684x3037 TIFF, while the bigger one to a 337868x5258 TIFF. I see no reason for this huge width... The TIFF, when loaded in QGIS as a raster layer, fits its position perfectly but renders very sllow.
– Alexei Kouprianov
Dec 14 at 21:19
ah. k I suspected that with my last statement in the answer. so I would recommend maybe clipping the Raster to your desired extent or study area. Hard to say for sure why the extent change. I dont remember this being an issue pre Qgis 3 but did see it when re-projecting certain rasters.
– SaultDon
Dec 14 at 21:30
Solved! Solved! Thank you! Your suggestion to pay attention to the file parameters made me to reconsider the graphical file dimensions. The extreme width of the file made me suspicious and I discovered a huge misprint in one of the 141 points (755.3261 East instead of 75.3261 East) which escaped my attention before. How stupid... )
– Alexei Kouprianov
Dec 14 at 21:35
add a comment |
Solved. The whole thing was caused by a huge misprint in the coordinates of one of the many points used for georeferencing (it was 755.3261 East instead of 75.3261 East).
answered Dec 14 at 21:37
Alexei Kouprianov
362
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
By default I don't believe QGIS applies and type of lossy or lossless compression to exported images.
When you are ready to export the georeferenced image, there are some options available to begin compressing the images.
There is the compression option but seems a little limited and offers 4 options:
- none
- LZW
- Packbits
- Deflate
But it might be better to choose something like None, which will result in a large file, but this is a scratch dataset that you can consider disposing of if the next step is successful!
With the new large tiff in QGIS. You can right-click it and choose Export > Save As...
That opens the Save raster layer as... window and in there look for Create Options and place a checkmark there.
This will enable the profile settings which have some sane defaults like High Compression which I think is lossless and JPEG Compression which might be lossy.
Another culprit for the single tiff you have being so large is that it's extent is rather large and could be filling in with nodata or some other value.
answered Dec 14 at 21:09
SaultDon
7,73812561
The export parameters are the same for all files, I use "Compression: none" very consistently. Geometry of the neighbouring file is nearly the same (there are corners filled with black, but they are of similar proportions to those in other files). For some unknown reason, however, the smaller neighbour is converted to a 6684x3037 TIFF, while the bigger one to a 337868x5258 TIFF. I see no reason for this huge width... The TIFF, when loaded in QGIS as a raster layer, fits its position perfectly but renders very sllow.
– Alexei Kouprianov
Dec 14 at 21:19
ah. k I suspected that with my last statement in the answer. so I would recommend maybe clipping the Raster to your desired extent or study area. Hard to say for sure why the extent change. I dont remember this being an issue pre Qgis 3 but did see it when re-projecting certain rasters.
– SaultDon
Dec 14 at 21:30
Solved! Solved! Thank you! Your suggestion to pay attention to the file parameters made me to reconsider the graphical file dimensions. The extreme width of the file made me suspicious and I discovered a huge misprint in one of the 141 points (755.3261 East instead of 75.3261 East) which escaped my attention before. How stupid... )
– Alexei Kouprianov
Dec 14 at 21:35
add a comment |
By default I don't believe QGIS applies and type of lossy or lossless compression to exported images.
When you are ready to export the georeferenced image, there are some options available to begin compressing the images.
There is the compression option but seems a little limited and offers 4 options:
- none
- LZW
- Packbits
- Deflate
But it might be better to choose something like None, which will result in a large file, but this is a scratch dataset that you can consider disposing of if the next step is successful!
With the new large tiff in QGIS. You can right-click it and choose Export > Save As...
That opens the Save raster layer as... window and in there look for Create Options and place a checkmark there.
This will enable the profile settings which have some sane defaults like High Compression which I think is lossless and JPEG Compression which might be lossy.
Another culprit for the single tiff you have being so large is that it's extent is rather large and could be filling in with nodata or some other value.
answered Dec 14 at 21:09
SaultDon
7,73812561
The export parameters are the same for all files, I use "Compression: none" very consistently. Geometry of the neighbouring file is nearly the same (there are corners filled with black, but they are of similar proportions to those in other files). For some unknown reason, however, the smaller neighbour is converted to a 6684x3037 TIFF, while the bigger one to a 337868x5258 TIFF. I see no reason for this huge width... The TIFF, when loaded in QGIS as a raster layer, fits its position perfectly but renders very sllow.
– Alexei Kouprianov
Dec 14 at 21:19
ah. k I suspected that with my last statement in the answer. so I would recommend maybe clipping the Raster to your desired extent or study area. Hard to say for sure why the extent change. I dont remember this being an issue pre Qgis 3 but did see it when re-projecting certain rasters.
– SaultDon
Dec 14 at 21:30
Solved! Solved! Thank you! Your suggestion to pay attention to the file parameters made me to reconsider the graphical file dimensions. The extreme width of the file made me suspicious and I discovered a huge misprint in one of the 141 points (755.3261 East instead of 75.3261 East) which escaped my attention before. How stupid... )
– Alexei Kouprianov
Dec 14 at 21:35
add a comment |
By default I don't believe QGIS applies and type of lossy or lossless compression to exported images.
When you are ready to export the georeferenced image, there are some options available to begin compressing the images.
There is the compression option but seems a little limited and offers 4 options:
- none
- LZW
- Packbits
- Deflate
But it might be better to choose something like None, which will result in a large file, but this is a scratch dataset that you can consider disposing of if the next step is successful!
With the new large tiff in QGIS. You can right-click it and choose Export > Save As...
That opens the Save raster layer as... window and in there look for Create Options and place a checkmark there.
This will enable the profile settings which have some sane defaults like High Compression which I think is lossless and JPEG Compression which might be lossy.
Another culprit for the single tiff you have being so large is that it's extent is rather large and could be filling in with nodata or some other value.
answered Dec 14 at 21:09
SaultDon
7,73812561
By default I don't believe QGIS applies and type of lossy or lossless compression to exported images.
When you are ready to export the georeferenced image, there are some options available to begin compressing the images.
There is the compression option but seems a little limited and offers 4 options:
- none
- LZW
- Packbits
- Deflate
But it might be better to choose something like None, which will result in a large file, but this is a scratch dataset that you can consider disposing of if the next step is successful!
With the new large tiff in QGIS. You can right-click it and choose Export > Save As...
That opens the Save raster layer as... window and in there look for Create Options and place a checkmark there.
This will enable the profile settings which have some sane defaults like High Compression which I think is lossless and JPEG Compression which might be lossy.
Another culprit for the single tiff you have being so large is that it's extent is rather large and could be filling in with nodata or some other value.
answered Dec 14 at 21:09
SaultDon
7,73812561
answered Dec 14 at 21:09
SaultDon
7,73812561
answered Dec 14 at 21:09
SaultDon
7,73812561
answered Dec 14 at 21:09
SaultDon
7,73812561
7,73812561
The export parameters are the same for all files, I use "Compression: none" very consistently. Geometry of the neighbouring file is nearly the same (there are corners filled with black, but they are of similar proportions to those in other files). For some unknown reason, however, the smaller neighbour is converted to a 6684x3037 TIFF, while the bigger one to a 337868x5258 TIFF. I see no reason for this huge width... The TIFF, when loaded in QGIS as a raster layer, fits its position perfectly but renders very sllow.
– Alexei Kouprianov
Dec 14 at 21:19
ah. k I suspected that with my last statement in the answer. so I would recommend maybe clipping the Raster to your desired extent or study area. Hard to say for sure why the extent change. I dont remember this being an issue pre Qgis 3 but did see it when re-projecting certain rasters.
– SaultDon
Dec 14 at 21:30
Solved! Solved! Thank you! Your suggestion to pay attention to the file parameters made me to reconsider the graphical file dimensions. The extreme width of the file made me suspicious and I discovered a huge misprint in one of the 141 points (755.3261 East instead of 75.3261 East) which escaped my attention before. How stupid... )
– Alexei Kouprianov
Dec 14 at 21:35
add a comment |
The export parameters are the same for all files, I use "Compression: none" very consistently. Geometry of the neighbouring file is nearly the same (there are corners filled with black, but they are of similar proportions to those in other files). For some unknown reason, however, the smaller neighbour is converted to a 6684x3037 TIFF, while the bigger one to a 337868x5258 TIFF. I see no reason for this huge width... The TIFF, when loaded in QGIS as a raster layer, fits its position perfectly but renders very sllow.
– Alexei Kouprianov
Dec 14 at 21:19
ah. k I suspected that with my last statement in the answer. so I would recommend maybe clipping the Raster to your desired extent or study area. Hard to say for sure why the extent change. I dont remember this being an issue pre Qgis 3 but did see it when re-projecting certain rasters.
– SaultDon
Dec 14 at 21:30
Solved! Solved! Thank you! Your suggestion to pay attention to the file parameters made me to reconsider the graphical file dimensions. The extreme width of the file made me suspicious and I discovered a huge misprint in one of the 141 points (755.3261 East instead of 75.3261 East) which escaped my attention before. How stupid... )
– Alexei Kouprianov
Dec 14 at 21:35
The export parameters are the same for all files, I use "Compression: none" very consistently. Geometry of the neighbouring file is nearly the same (there are corners filled with black, but they are of similar proportions to those in other files). For some unknown reason, however, the smaller neighbour is converted to a 6684x3037 TIFF, while the bigger one to a 337868x5258 TIFF. I see no reason for this huge width... The TIFF, when loaded in QGIS as a raster layer, fits its position perfectly but renders very sllow.
– Alexei Kouprianov
Dec 14 at 21:19
The export parameters are the same for all files, I use "Compression: none" very consistently. Geometry of the neighbouring file is nearly the same (there are corners filled with black, but they are of similar proportions to those in other files). For some unknown reason, however, the smaller neighbour is converted to a 6684x3037 TIFF, while the bigger one to a 337868x5258 TIFF. I see no reason for this huge width... The TIFF, when loaded in QGIS as a raster layer, fits its position perfectly but renders very sllow.
– Alexei Kouprianov
Dec 14 at 21:19
ah. k I suspected that with my last statement in the answer. so I would recommend maybe clipping the Raster to your desired extent or study area. Hard to say for sure why the extent change. I dont remember this being an issue pre Qgis 3 but did see it when re-projecting certain rasters.
– SaultDon
Dec 14 at 21:30
ah. k I suspected that with my last statement in the answer. so I would recommend maybe clipping the Raster to your desired extent or study area. Hard to say for sure why the extent change. I dont remember this being an issue pre Qgis 3 but did see it when re-projecting certain rasters.
– SaultDon
Dec 14 at 21:30
Solved! Solved! Thank you! Your suggestion to pay attention to the file parameters made me to reconsider the graphical file dimensions. The extreme width of the file made me suspicious and I discovered a huge misprint in one of the 141 points (755.3261 East instead of 75.3261 East) which escaped my attention before. How stupid... )
– Alexei Kouprianov
Dec 14 at 21:35
Solved! Solved! Thank you! Your suggestion to pay attention to the file parameters made me to reconsider the graphical file dimensions. The extreme width of the file made me suspicious and I discovered a huge misprint in one of the 141 points (755.3261 East instead of 75.3261 East) which escaped my attention before. How stupid... )
– Alexei Kouprianov
Dec 14 at 21:35
add a comment |
Solved. The whole thing was caused by a huge misprint in the coordinates of one of the many points used for georeferencing (it was 755.3261 East instead of 75.3261 East).
answered Dec 14 at 21:37
Alexei Kouprianov
362
add a comment |
Solved. The whole thing was caused by a huge misprint in the coordinates of one of the many points used for georeferencing (it was 755.3261 East instead of 75.3261 East).
answered Dec 14 at 21:37
Alexei Kouprianov
362
add a comment |
Solved. The whole thing was caused by a huge misprint in the coordinates of one of the many points used for georeferencing (it was 755.3261 East instead of 75.3261 East).
answered Dec 14 at 21:37
Alexei Kouprianov
362
Solved. The whole thing was caused by a huge misprint in the coordinates of one of the many points used for georeferencing (it was 755.3261 East instead of 75.3261 East).
answered Dec 14 at 21:37
Alexei Kouprianov
362
answered Dec 14 at 21:37
Alexei Kouprianov
362
answered Dec 14 at 21:37
Alexei Kouprianov
362
answered Dec 14 at 21:37
Alexei Kouprianov
362
362
add a comment |
add a comment |
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