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Hi Pradeep,
<div>to calculate the destination coordinates of the two points, you can call gdaltransform with the same gcp parameters as gdal_translate und gdalwarp before. Gdal uses the same algorithm for transforming raster and vector data.</div>
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<div>Martin<br>
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<div dir="ltr">Von meinem iPhone gesendet</div>
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<blockquote type="cite">Am 26.02.2020 um 17:00 schrieb Pradeep kumar <parthivpradeep@gmail.com>:<br>
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<div dir="ltr">Hi All,
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I am georeferencing aerial images with gcps using gdal_translate and gdalwarp. Before georeferencing image(warping) I would like to check quality and final result on a control_point cp (eg disabeld gcps). Therefore I would like to calculate the coordinates
in destination image for a independent control_point based on the interpolation method (n-order, helmet and spline) which is NOT used by warping itself. Afterwards compare positions with estimated coordinates of that cp.
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<div>Example:<br>
Lets say, I have 10 gcps. I take 8 gcps, using `-order n` generate a `model`. Then predict destination values for rest of the two control points using this `model`. Finally compute shift between predicted and actual values for these control points.<br>
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<div>Could you please let me know if any gdal tool does this? Can any one give some insight how to implement this in python?<br>
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<div>I have checked following stack exchange issues.<br>
1. <a href="https://gis.stackexchange.com/questions/225931/python-gdal-how-to-obtain-dx-dy-residual-errors-for-gcps-after-gdalwarp-usage">
https://gis.stackexchange.com/questions/225931/python-gdal-how-to-obtain-dx-dy-residual-errors-for-gcps-after-gdalwarp-usage</a> (self written n-grad interpolation, is there any validaton form offical gdal?)<br>
2. <a href="http://osgeo-org.1560.x6.nabble.com/GCPs-to-geo-transform-td3771045.html">
http://osgeo-org.1560.x6.nabble.com/GCPs-to-geo-transform-td3771045.html</a><br>
3. <a href="https://gis.stackexchange.com/questions/102111/preserve-gcps-after-gdalwarp">
https://gis.stackexchange.com/questions/102111/preserve-gcps-after-gdalwarp</a><br clear="all">
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<div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr">Best Regards,
<div>Pradeep Gulla</div>
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