Optimizing is a way of repurposing an image without having to reencode it. Optimize is MrSID-specific and offers special options for existing MG3 and MG4 files. Any MG3 or MG4 image can be optimized unless it was encoded with the -nonoptimizable switch. In additional to flat files, MrSID composite images can also optimized.
Optimizing operations do not decrement the data cartridge.
Optimizing operations include cropping and resampling (or downsampling). For information on cropping, see Cropping an Image.
The switch -resample (sint) resamples an MG3 or MG4 file by a power of 2.
The resample feature allows zoom levels to be removed from an MG3 or MG4 image, resulting in a smaller file with less detail. The number of levels to remove is mapped to a "resampling factor," which is based on the number of zoom levels the source file contains. The resampling factor is a power of two that relates to the amount of detail that is removed. For example, a resampling factor of two would remove one level and contain half as much detail as the original image. A resampling factor of four would remove two levels and contain one fourth of the detail of the original image.