Thanks for the response and the wise advice, Even. I'll do it in that way. On Thu, Dec 13, 2012 at 8:06 PM, Even Rouault <even.roua...@mines-paris.org> wrote: > Le jeudi 13 décembre 2012 19:58:50, Jorge Arevalo a écrit : >> Hello, >> >> I want to modify every single pixel of a 1 band GeoTiff file, >> following a formula (multiply each pixel for a value and then add >> another value). >> >> output_pixel[i][j] = input_pixel[i][j] * K[i][j] + C[i][j] >> >> I can't apply a linear scale (it would be as easier as -scale option >> in gdal_translate). Sounds more like applying a mask to the band's >> data. >> >> My first approach is to get every data block of the raster (IReadBlock >> call), apply the transformation to every single pixel ( = apply a mask >> to the data block), and put the block in the output raster. >> >> Is there any other faster/smarter approach? > > I would follow exactly the same approach. If you don't do in-place update, be > carefull that the source and target rasters have exactly the same block size > and data type if you want to use directly ReadBlock() / WriteBlock(). If not, > you must use ReadBlock() / RasterIO(GF_Write, ....)
-- Jorge Arevalo http://www.krop.com/jorgearevalo _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev