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
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