Output pixel value = (raw pixel value * scale) + offset On Fri, Mar 23, 2012 at 5:44 PM, Saâd HESSANE <saad.hess...@gmail.com>wrote:
> Ok, thank you again Chaitanya, > > But what is the function of this two element? > > > 2012/3/23 Chaitanya kumar CH <chaitanya...@gmail.com> > >> Saâd, >> >> A VRT raster band can be derived from more than one source. >> >> Offset and Scale elements apply to the whole VRT raster band. >> The ScaleOffset and ScaleRatio perform the same task but it is done only >> on that particular ComplexSource. >> >> On Fri, Mar 23, 2012 at 3:43 PM, Saâd HESSANE <saad.hess...@gmail.com>wrote: >> >>> Hy all, >>> >>> The vrt format allow defining the scale and offset element. But the >>> documentation is not clear about that : >>> >>> - *Offset*: This optional element contains the offset that should be >>> applied when computing "real" pixel values from scaled pixel values on a >>> raster band. The default is 0.0. >>> - *Scale*: This optional element contains the scale that should be >>> applied when computing "real" pixel values from scaled pixel values on a >>> raster band. The default is 1.0. >>> >>> What that it's mean ? If the value of offset is 1 what that it's change? >>> >>> And this two elements are use in the *VRTRasterBand* element. What >>> about *ScaleOffset* and *ScaleRatio* in the *ComplexSource* element? >>> >>> Thank you. >>> >>> _______________________________________________ >>> gdal-dev mailing list >>> gdal-dev@lists.osgeo.org >>> http://lists.osgeo.org/mailman/listinfo/gdal-dev >>> >> >> >> >> -- >> Best regards, >> Chaitanya kumar CH. >> >> +91-9494447584 >> 17.2416N 80.1426E >> > > -- Best regards, Chaitanya kumar CH. +91-9494447584 17.2416N 80.1426E
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