Bug report #13737
Qgis not calculate correct min and max of rasters
|Affected QGIS version:||2.12.0||Regression?:||No|
|Operating System:||Easy fix?:||No|
|Pull Request or Patch supplied:||No||Resolution:||end of life|
|Crashes QGIS or corrupts data:||No||Copied to github as #:||21764|
inside qgis 2.12.0 and 2.10 min and max of a raster
are not correctly calculated
layer name: dtm.ascii (EPSG 32632)
inside qgis metadata:
Arc/Info ASCII Grid
X: 871 Y:.1270 Bande: 1
from command line with gdalinfo.exe data is correct:
C:\\Users\\stefano\\Desktop\\verifica Lidar>"C:\\Program Files\\QGIS Lyon\\bin\\gdalinfo.exe" -mm "dtm.ascii"
Driver: AAIGrid/Arc/Info ASCII Grid
with grass r.report the data is correct:
Valid cells: 1105738
No-data cells: 432
Mean value: -0.0588224895434
Standard deviation: 0.799352883696
#2 Updated by malcom jamal over 4 years ago
sorry file lost........
another file same problem.......
inside Qgis min max are: -0.652444 0.354595
with raster layer statistics:
Valid cells: 19831
No-data cells: 44086
Minimum value: -0.99023763639
Maximum value: 0.595650260614
Mean value: 0.0249915921011
Standard deviation: 0.20831555902
i have only tested with 2.12 and 2.10
#3 Updated by Giovanni Manghi over 4 years ago
- Resolution set to invalid
- Status changed from Feedback to Closed
qgis uses by default the "cumulative count cut" method to compute min/max, change it to "min/max" if you want to do symbology using a scale that uses absolute min/max values.
#4 Updated by Idan Miara almost 4 years ago
- Status changed from Closed to Reopened
running: qgis v2.14.1 Win64.
I have a problem that might be connected:
On some HFA rasters Estimated (faster) Cumulative count is wrong.
I attach HFA RLE compressed raster: srtm_14_06.img
run(from qgis\\bin): gdal_translate -of HFA srtm_14_06.img X.img
(should produce identical raster, just uncompressed)
Open both rasters with qgis. play with style options:
1. Min/Max + Actual(slower): [-20 - 2871]. (OK) - same for both files
2. Min/Max + Estimate(faster): [-20 - 2871]. (OK) - same for both files
3. Cumulative count cut 2%-98% + Actual(slower): 20 - 2056. (might be) - same for both files
4. Cumulative count cut 2%-98% + Estimate(faster): original: [20 - 2059]. converted: [3 - 1010]. (BUG!!!)
5. Cumulative count cut 0%-100% + Actual(slower): -20 - 2869. (a little odd, should be 2871) - same for both files
6. Cumulative count cut 0%-100% + Estimate(faster): original: [-9 - 2701]. converted: [-6 - 1227]. (BUG!!!)
#6 Updated by Giovanni Manghi about 1 year ago
- Resolution changed from invalid to end of life
- Status changed from Reopened to Closed
End of life notice: QGIS 2.18 LTR
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