Hi Evan, I was mistaken in which gdal program drops the XMP tags. gdal_translate actually transfers the XMP tags properly from the input jpg file to tif output. But a subsequent gdalwarp on that tif does not pass the XMP tags to its output.
So the sequence is, for example: step 1: Convert jpg to geotiff, using specified gcps gdal_translate -gcp 7952 0 -121.7912 36.8015 -gcp 7952 5304 -121.7910 36.8012 -gcp 0 5304 -121.7915 36.8010 -gcp 0 0 -121.7917 36.8013 -of GTiff -co COMPRESS=DEFLATE -a_srs EPSG:4326 DSC01221.JPG test.tif step 2: Warp the geotiff gdalwarp -t_srs EPSG:4326 -of GTiff -dstalpha test.tif testwarp.tif The geotiff produced by step 1 contains the XMP tags as expected. But the warped geotiff produced by step 2 does not contain any XMP tags. How best to provide a test jpg? The ones I have are all 20+ MBytes. Thanks Tom -------------------------------------------------- Thomas C. O'Reilly Monterey Bay Aquarium Research Institute 7700 Sandholdt Road Moss Landing, California 95039-9644 831-775-1766 (voice) 831-775-1620 (FAX) orei...@mbari.org (email) http://www.mbari.org (World-wide Web) "The machine does not isolate us from the great mysteries of nature, but plunges us more deeply into them." - ANTOINE DE SAINT-EXUPERY "Wind, Sand, and Stars" (1939) ----- Original Message ----- From: "Even Rouault" <even.roua...@spatialys.com> To: "Tom O'Reilly" <orei...@mbari.org>, "gdal-dev" <gdal-dev@lists.osgeo.org> Sent: Monday, August 8, 2022 12:13:03 PM Subject: Re: [gdal-dev] gdal_translate drops XMP exif tags Tom, It would be interesting if you could provide an image how to reproduce that With the sample file from the autotest suite, I can't reproduce that: $ gdal_translate ../autotest/gdrivers/data/jpeg/byte_with_xmp.jpg out.tif $ gdalinfo out.tif -mdd all Driver: GTiff/GeoTIFF Files: out.tif Size is 1, 1 Metadata (xml:XMP): <?xpacket begin='' id='W5M0MpCehiHzreSzNTczkc9d'?> <x:xmpmeta xmlns:x='adobe:ns:meta/' x:xmptk='Image::ExifTool 7.89'> <rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#'> <rdf:Description rdf:about='' xmlns:dc='http://purl.org/dc/elements/1.1/'> <dc:description> <rdf:Alt> <rdf:li xml:lang='x-default'>Description</rdf:li> </rdf:Alt> </dc:description> <dc:subject> <rdf:Bag> <rdf:li>XMP</rdf:li> <rdf:li>Test</rdf:li> </rdf:Bag> </dc:subject> <dc:title> <rdf:Alt> <rdf:li xml:lang='x-default'>Title</rdf:li> </rdf:Alt> </dc:title> </rdf:Description> <rdf:Description rdf:about='' xmlns:tiff='http://ns.adobe.com/tiff/1.0/'> <tiff:BitsPerSample> <rdf:Seq> <rdf:li>8</rdf:li> </rdf:Seq> </tiff:BitsPerSample> <tiff:Compression>1</tiff:Compression> <tiff:ImageLength>20</tiff:ImageLength> <tiff:ImageWidth>20</tiff:ImageWidth> <tiff:PhotometricInterpretation>1</tiff:PhotometricInterpretation> <tiff:PlanarConfiguration>1</tiff:PlanarConfiguration> <tiff:SamplesPerPixel>1</tiff:SamplesPerPixel> </rdf:Description> </rdf:RDF> </x:xmpmeta> <?xpacket end='w'?> Metadata (DERIVED_SUBDATASETS): DERIVED_SUBDATASET_1_NAME=DERIVED_SUBDATASET:LOGAMPLITUDE:out.tif DERIVED_SUBDATASET_1_DESC=log10 of amplitude of input bands from out.tif Image Structure Metadata: INTERLEAVE=BAND Corner Coordinates: Upper Left ( 0.0, 0.0) Lower Left ( 0.0, 1.0) Upper Right ( 1.0, 0.0) Lower Right ( 1.0, 1.0) Center ( 0.5, 0.5) Band 1 Block=1x1 Type=Byte, ColorInterp=Gray Le 08/08/2022 à 20:32, Tom O'Reilly a écrit : > gdal_translate output .tif file does not contain XMP tags that were > present in the input .jpg file. > The output file contains many of the input EXIF tags, aggregated as > the GDALMetadata tag, but not the XMP tags. > Why does gdal_translate remove XMP tags - is there an option to > preserve them? > > Thanks > Tom > -------------------------------------------------- > Thomas C. O'Reilly > Monterey Bay Aquarium Research Institute > 7700 Sandholdt Road > Moss Landing, California 95039-9644 > 831-775-1766 (voice) > 831-775-1620 (FAX) > orei...@mbari.org (email) > http://www.mbari.org (World-wide Web) > > "The machine does not isolate us from the great mysteries > of nature, but plunges us more deeply into them." > > - ANTOINE DE SAINT-EXUPERY > "Wind, Sand, and Stars" (1939) > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev -- http://www.spatialys.com My software is free, but my time generally not _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev