Re: [gdal-dev] Question about using crop_to_cutline
Even Rouault even.rouault at mines-paris.org writes: This is the very same topic that is discussed in http://trac.osgeo.org/gdal/ticket/3947 . There's no solution to your problem, but some background discussion that explains the current behaviour. This is close to a problem I had once with creating mosaics from individually warped orthophotos. Accurately calculated extents make pixels to slide a bit and individually warped images do not share any common canvas for their pixels. I sketched a plan for forcing the warped image to use a common canvas and found a python guy to make a program. I have been satisfied with the result. I believe that the same solution will work for you. You must widen the -te parameters that is calculated by crop_to_cutline to each direction so that they match exactly with some pixel row and line of the original image. See figures 3, 4, and 5 in http://www.scangis.org/scangis2007/papers/r3_rahkonen.pdf. The python code is there too. Without understanding anything about programming I suppose that the job is done with this: minmax = get_minmax(tm32_coords) minmax_wider = [ (int(math.floor(minmax[0][0])), int(math.floor(minmax[0][1]))), (int(math.ceil (minmax[1][0])), int(math.ceil (minmax[1][1]))), ] log(Extents (min,max): + str(minmax), outfilename) log(Widened extents (min,max): + str(minmax_wider), outfilename) -Jukka Rahkonen- ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Question about using crop_to_cutline
At the time I created the ticket I had created a workaround that uses gdal_translate to clip a rectangular window and gdal_rasterize to burn an inverse image of the vector. Interested folks can email me for the script (does the list take attachments?). The script makes some assumptions about your data type (e.g. 0 is assigned as nodata) but you can change those assumptions to suit your needs. I plan to make the feature request I mentioned in #3947. -marius To: gdal-dev@lists.osgeo.org From: jukka.rahko...@mmmtike.fi Date: Fri, 26 Oct 2012 09:05:06 + Subject: Re: [gdal-dev] Question about using crop_to_cutline Even Rouault even.rouault at mines-paris.org writes: This is the very same topic that is discussed in http://trac.osgeo.org/gdal/ticket/3947 . There's no solution to your problem, but some background discussion that explains the current behaviour. This is close to a problem I had once with creating mosaics from individually warped orthophotos. Accurately calculated extents make pixels to slide a bit and individually warped images do not share any common canvas for their pixels. I sketched a plan for forcing the warped image to use a common canvas and found a python guy to make a program. I have been satisfied with the result. I believe that the same solution will work for you. You must widen the -te parameters that is calculated by crop_to_cutline to each direction so that they match exactly with some pixel row and line of the original image. See figures 3, 4, and 5 in http://www.scangis.org/scangis2007/papers/r3_rahkonen.pdf. The python code is there too. Without understanding anything about programming I suppose that the job is done with this: minmax = get_minmax(tm32_coords) minmax_wider = [ (int(math.floor(minmax[0][0])), int(math.floor(minmax[0][1]))), (int(math.ceil (minmax[1][0])), int(math.ceil (minmax[1][1]))), ] log(Extents (min,max): + str(minmax), outfilename) log(Widened extents (min,max): + str(minmax_wider), outfilename) -Jukka Rahkonen- ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Question about using crop_to_cutline
Hi I have exacly the same problem. It is resampling to the extent of the polygon instead of croping just the pixels inside the polygon and using the pixel frame of the original image. How can this be fixed? Regards Luis Lisboa - ORIGINAL MESSAGE-- Greetings I have a raster image and a shapefile polygon and I wanted to crop the raster for just to have valid pixels inside the polygon. I have used crop_to_cutline but here is a problem: It produces a raster map but pixels does not geographically match with the original raster map. So, i produce a raster map but I'm not able to compare with original image since there is a small displacement. How can I obtain a raster map without this mismatch? Thank you Regards, Antonio GDAL version 1.9.1 ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Question about using crop_to_cutline
I have a close functionality in Mirone but it was developed mainly for grids, though it works also with images. With a grid/image loaded, load the polygon too. Next right-click on the polygon line and select ROI Crop Tools - Crop Image (or any of the other related options) and it's done. One thing you may not like is that the resulting image is not of the same size (extent) as the original. This is so because I (don't remember anymore why) decided to save only the extent corresponding to the BoundingBox of the polygon. Joaquim Hi I have exacly the same problem. It is resampling to the extent of the polygon instead of croping just the pixels inside the polygon and using the pixel frame of the original image. How can this be fixed? Regards Luis Lisboa - ORIGINAL MESSAGE-- Greetings I have a raster image and a shapefile polygon and I wanted to crop the raster for just to have valid pixels inside the polygon. I have used crop_to_cutline but here is a problem: It produces a raster map but pixels does not geographically match with the original raster map. So, i produce a raster map but I'm not able to compare with original image since there is a small displacement. How can I obtain a raster map without this mismatch? Thank you Regards, Antonio GDAL version 1.9.1 ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Question about using crop_to_cutline
Hi Sorry Joaquim but I'm really trying to find a solution based on GDAL. Thanks Antonio I have a close functionality in Mirone but it was developed mainly for grids, though it works also with images. With a grid/image loaded, load the polygon too. Next right-click on the polygon line and select ROI Crop Tools - Crop Image (or any of the other related options) and it's done. One thing you may not like is that the resulting image is not of the same size (extent) as the original. This is so because I (don't remember anymore why) decided to save only the extent corresponding to the BoundingBox of the polygon. Joaquim ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
Re: [gdal-dev] Question about using crop_to_cutline
Le mercredi 24 octobre 2012 17:19:45, António Rocha a écrit : Greetings I have a raster image and a shapefile polygon and I wanted to crop the raster for just to have valid pixels inside the polygon. I have used crop_to_cutline but here is a problem: It produces a raster map but pixels does not geographically match with the original raster map. So, i produce a raster map but I'm not able to compare with original image since there is a small displacement. How can I obtain a raster map without this mismatch? This is the very same topic that is discussed in http://trac.osgeo.org/gdal/ticket/3947 . There's no solution to your problem, but some background discussion that explains the current behaviour. Thank you Regards, Antonio GDAL version 1.9.1 ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
[gdal-dev] Question about using crop_to_cutline
Greetings I have a raster image and a shapefile polygon and I wanted to crop the raster for just to have valid pixels inside the polygon. I have used crop_to_cutline but here is a problem: It produces a raster map but pixels does not geographically match with the original raster map. So, i produce a raster map but I'm not able to compare with original image since there is a small displacement. How can I obtain a raster map without this mismatch? Thank you Regards, Antonio GDAL version 1.9.1 ___ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
