[gdal-dev] Fwd: oblique cuts on a raster using python GDAL

[Naima Dambrine]

---------- Forwarded message ---------
De : Naima Dambrine <naima.etienne at gmail.com>
Date: mar. 7 nov. 2023 à 09:16
Subject: Re: [gdal-dev] oblique cuts on a raster using python GDAL
To: Javier Jimenez Shaw <j1 at jimenezshaw.com>


Hi,

Thank you very much for your help, it let me try and try again, and you are
right when you say that it is possible.
I finally obtain a perfect cut in python, here is the code :

gdal.Warp(

output-raster,

raster-ds,

format=  ‘GTiff’,

cutlineDSName= ‘geometry-extraction.shp’,

cropToCutline = True,

xRes = None, yRes=None,

resampleAlg=’nearest’,

multithread= True,

srcNoData=None, dstNodata=255,

options=[‘COMPRESS=DEFLATE’, ‘PREDICTOR=2’, ‘ZLEVEL=9']

)


Have a nice day,

Naïma


Le lun. 6 nov. 2023 à 17:23, Javier Jimenez Shaw <j1 at jimenezshaw.com> a
écrit :

>
>
> On Mon, 6 Nov 2023 at 14:43, Naima Dambrine <naima.etienne at gmail.com>
> wrote:
>
>> Thank you, can you please paste a zoom image of your result ?
>>
>> because if i translate your gdalwarp in python :
>>
>> gdalwarp 3635_rasters_agreges.jp2 salida.tif -cutline
>> geometry_extraction.shp -crop_to_cutline -dstnodata 0 -cl
>> geometry_extraction -overwrite -of GTiff
>>
>> gdal.Warp('salida.tif', '3635_rasters_agreges.jp2', format='GTiff',
>> cutlineDSName='geometry_extraction.shp', cropToCutline=True, dstNoData=0)
>>
>> it's the same code ...  and I do not obtain a clean image at all
>>
>>
>>
>> Le lun. 6 nov. 2023 à 14:05, Javier Jimenez Shaw <j1 at jimenezshaw.com> a
>> écrit :
>>
>>> This is working for me (and also in gdal 3.8.0):
>>>
>>> gdalwarp 3635_rasters_agreges.jp2 salida.tif -cutline
>>> geometry_extraction.shp -crop_to_cutline -dstnodata 0 -cl
>>> geometry_extraction -overwrite -of GTiff
>>>
>>> About the "white" pixels inside the image, it could be that a single
>>> band has a value of 0 (not that strange). Then it is transparent, and you
>>> see the background color. (to avoid those "color misunderstandings" I have
>>> a pink background color, that is not white).
>>>
>>> On Mon, 6 Nov 2023 at 12:35, Naima Dambrine <naima.etienne at gmail.com>
>>> wrote:
>>>
>>>> Hi Javier,
>>>>
>>>> Thank you, good news ...
>>>>
>>>> I'm on Ubuntu 20.04 with gdal 3.6.2. Yes, the original raster format is
>>>> JP2, but my output format is GTiff. Here is exactly what I do :
>>>>
>>>> cut_ds = gdal.Warp(outfile, jp2_ds, format='GTiff',
>>>> cutlineDCName=shape_file_path,
>>>> cropToCutline=True,
>>>> copyMetadat=True,
>>>> dstNodata=0)
>>>>
>>>> What I see is that there are still black pixels around the image, as
>>>> well as white pixels inside the image.
>>>> Another point to consider is that, despite the use of compression, the
>>>> output file is 75.3 MB, compared with around 14 MB with a JP2 format. Why
>>>> is this?
>>>>
>>>> my output :
>>>>
>>>>
>>>>
>>>>
>>>> Le lun. 6 nov. 2023 à 11:33, Javier Jimenez Shaw <j1 at jimenezshaw.com>
>>>> a écrit :
>>>>
>>>>> Hi Naima
>>>>>
>>>>> I have been testing with your dataset. To me, using the GDAL in Ubuntu
>>>>> 22.04 (3.4.1) seems to be a problem with the JP2 output format. If you
>>>>> output as geotiff it works fine.
>>>>>
>>>>> On Sun, 5 Nov 2023 at 19:43, Rahkonen Jukka via gdal-dev <
>>>>> gdal-dev at lists.osgeo.org> wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>>
>>>>>>
>>>>>> Please add gdalinfo of the source image. Even better if you can share
>>>>>> the image.
>>>>>>
>>>>>>
>>>>>>
>>>>>> -Jukka Rahkonen-
>>>>>>
>>>>>>
>>>>>>
>>>>>> *Lähettäjä:* gdal-dev <gdal-dev-bounces at lists.osgeo.org> *Puolesta *Naima
>>>>>> Dambrine via gdal-dev
>>>>>> *Lähetetty:* sunnuntai 5. marraskuuta 2023 17.35
>>>>>> *Vastaanottaja:* gdal-dev at lists.osgeo.org
>>>>>> *Aihe:* [gdal-dev] oblique cuts on a raster using python GDAL
>>>>>>
>>>>>>
>>>>>>
>>>>>> Hi ,
>>>>>>
>>>>>>
>>>>>>
>>>>>> I have problems with oblique cuts on a raster using python GDAL
>>>>>> (3.6.2)
>>>>>>
>>>>>>
>>>>>>
>>>>>> - with this line i obtain black borders around :
>>>>>>
>>>>>> gdal.warp('raster-dst' , raster-src',
>>>>>> cutLineDSName='geometry-extraction.shp', cropToCutline=True)
>>>>>>
>>>>>>
>>>>>>
>>>>>> - with this one, the crop is not clean on closer inspection:
>>>>>> residual black pixels around image and white pixels appear in the image.
>>>>>>
>>>>>> gdal. warp( 'raster-dst' , raster-src',
>>>>>> cutLineDSName='geometry-extraction.shp', cropToCutline=True,
>>>>>> copyMetaData=True, dstNodata=0)
>>>>>>
>>>>>>
>>>>>> I tried, without success, to refine with outputBounds=[minX, maxX,
>>>>>> minY, maxY], under QGIS directly ….
>>>>>> I've run out of ideas :/
>>>>>> A (naive) question comes to mind: Is it possible to make oblique cuts
>>>>>> with gdal.warp() & co?
>>>>>>
>>>>>> Naïma
>>>>>> _______________________________________________
>>>>>> gdal-dev mailing list
>>>>>> gdal-dev at lists.osgeo.org
>>>>>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>>>>
>>>>>
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