Thank you for your reply Guillaume I work with gdal and otb_convert to produce thing like that, but i would like to calculate the value for histogram cuttoff (by default 2%) to produce pleiades data with good contrast and colorimetry. I would like to have the same color (the same stretch) between multitemp images to produce ready to use data for application like mosaicking... I will share with you if i find an interesting workflow. Cheers Léo
Le mardi 3 janvier 2017 00:14:10 UTC+11, Guillaume Pasero a écrit : > > Hi Léo, > > In OTB there is an application to perform basic conversion : > otbcli_Convert. > > This applications allows to convert the dynamic of an image to an output > pixels type (linear and log transform supported). It will compute min/max > for each band and stretch this dynamic to the output range of your > destination pixel type (i.e. 0-255 for uint8). By default, 2% of the > histogram are cut on each side (can be tuned). You can also supply a mask > to discard pixels during the histogram computation (can be useful for > clouds). > Regards, > Guillaume > > On 12/12/2016 04:10 AM, Léo HUERTA wrote: > > Hi everybody, > > I 'm currently working on Pleiades Datasets, and i would like to perform > automatic contrast enhancement and color correction, and i would like to > know if anybody know a workflow to do that... > I would like to reproduce a thing like "OVR" from Pleiades Data > distributed by Airbus Defense & Space. > > I experimented software like Image magick with this kind of code: > convert -monitor -modulate 100,130 -channel R -gamma 1 -channel G -gamma > 0.95 -channel B -gamma 0.875 -channel RGB -sigmoidal-contrast 11x40% > %OUT%BUNDLE_ORTHO_RGB.TIF -compress lzw %OUT%BUNDLE_ORTHO_RGB_CC.TIF > It's not bad but, i spend lot of time trying to find the correct > parameters... And i don't know how to calculate them automatically. > > A good software (but not open source) do a thing like that: Spectral > discovery (by Geosage, an Australian company), this software perform L8 > pre-processing (for data visualisation only): this soft read metada (MTL > files, like DIMAP for pleiades), to estimate parameters for stretching, and > scaling to produce a good looking L8 RGB tiff. I think it is possible to do > that with the dimap but i don't know how... > > I have read a good paper about color correction for sat imagery: > An Inquiry on Contrast Enhancement Methods for Satellite Images > > They speak about to very good algo: MSR (Multi Scale Retinex) and LCC > (Local Color Correction), but i don't know how to aplly them on my Pleiades > dataset. > > > If anyone want to share about contrast enhancement and color correction, i > am very happy to share my ressource. > > Thank you for your time > > Léo > > > > -- > -- > Check the OTB FAQ at > http://www.orfeo-toolbox.org/FAQ.html > > You received this message because you are subscribed to the Google > Groups "otb-users" group. > To post to this group, send email to [email protected] > <javascript:> > To unsubscribe from this group, send email to > [email protected] <javascript:> > For more options, visit this group at > http://groups.google.com/group/otb-users?hl=en > --- > You received this message because you are subscribed to the Google Groups > "otb-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > For more options, visit https://groups.google.com/d/optout. > > > -- > <http://www.c-s.fr> *Guillaume PASERO* > Responsable technique > *Business Unit ESPACE & GeoInformation - Département Payload Data & > Applications* > > *CS Systèmes d'Information* > Parc de la Grande Plaine - 5, Rue Brindejonc des Moulinais - BP 15872 > 31506 Toulouse Cedex 05 - FRANCE > +33 561 17 64 21 - [email protected] <javascript:> > -- -- Check the OTB FAQ at http://www.orfeo-toolbox.org/FAQ.html You received this message because you are subscribed to the Google Groups "otb-users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/otb-users?hl=en --- You received this message because you are subscribed to the Google Groups "otb-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
