Re: [otb-users] Advice on Raster algebra with OTB

[Guillaume Pasero]

Hi Agustin, The BandMath tool only processes the images of equal sizes. So I would go with creating an image with repeated lines, and I think the VRT format can do that. After a quick search here, I think you can create : a VRT with the size of A, put inside a single 'SimpleSource' which is your one-line image B set the 'DstRect' parameter to the full dimension, it will stretch the one-line image to fit the full image you tell GDAL to use nearest neighbor interpolation : <SimpleSource resampling="nearest"> Regards, Guillaume On 11/05/2018 06:40 PM, Agustin Lobo wrote: In order to calculate reflectance from a multi-spectral radiance image acquired with a linear scanner, I also have a 1-row array of white reference values, that is: multi-spectral image A: x rows, y cols, z bands multi-spectral white reference image B: 1 row, y cols, z bands I would need to divide each row of A by B. In a simple notation: res <- a for(i in 1:nrow(a)){ res[i,,] <- a[i,,]*b } I'd like to this for relatively large images (x=969, y=640, z=224), avoiding any loop if possible. The most obvious strategy would be to create a b2 image by repeating the row of b x times and then use the otb raster arithmetic for a/b2. But is there an otb way to create such a b2? or perhaps another approach (I.e using the BandMath tool?) Thanks Agus -- 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 - guillaume.pas...@c-s.fr -- -- 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 otb-users@googlegroups.com To unsubscribe from this group, send email to otb-users+unsubscr...@googlegroups.com 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 otb-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.