NOTE: All switches are case-sensitive.
The following table describes switches for advanced encoding options in MrSID. For JPEG 2000 switches, see JPEG 2000 Encoding.
| Switch | Value | Notes |
|---|---|---|
| -blocksize/-bs | sint |
Block size affects the use of system resources. For MG3 and MG4 encoding, increasing block size may improve the lossless compression ratio, but at a possible cost of decreased quality in the compressed images. Decreasing this value may result in longer encoding times. Acceptable values: 5 – 64. Default: 64. For MG2 encoding, gigabyte-sized jobs should use a value of 1024, while larger jobs should use a value of 2048. Minimum value is 32. Default: 512. |
| -multiresample | string |
Sets the resampling method for a multiresolution mosaic. Accepted values are:
Default is "nearest". |
| -numThreads | int | The number of threads that you want to use for the encoding operation. See Concurrency Note: In previous releases of this documentation this switch was incorrectly listed as numthreads; the switch is case-sensitive and must be entered as numThreads. |
| -tpc | string |
Specifies transparency (nodata) color. Takes a comma separated list (see below). Used with MG2, MG3 and JPEG 2000 (for transparency options in MG4, use the -alphasource/-as switch). |
| -weight | float |
MG2 and MG3 only. A higher setting increases the emphasis on the grayscale aspect of a color image, while a lower setting increases the consistency of color between the compressed image and the original data. Acceptable values: 0.0 – 10.0. Default: 2.0. |
In MG4, transparency is handled through the alpha channel (see Alpha Bands and MrSID). For all other output formats, use the -tpc switch. This switch takes a list in the form <bandlist>@<color> where <bandlist> is a comma separated list of the band numbers or a range of bands, and the color is a color value.
For example, to specify zero as the color value for bands one through five enter the following:
1:5@0
To specify zero as the color value for all bands, enter the following:
REMAINDER@0
To specify 127 as the color value for the first band and 1 for the color value for all remaining bands, enter the following:
1@127, REMAINDER@1
For 8- and 16-bit RGB and grayscale image,s a transparency color can also be specified in RRR_GGG_BBB format. For more information on acceptable values, see Setting Transparency Metadata.
If you run GeoExpress on a machine with a multi-core processor or on a machine with multiple processors, GeoExpress creates multiple threads to process jobs more quickly. By default, GeoExpress uses the maximum number of threads available for optimal performance. The maximum number of threads equals the number of cores in your processor up to a maximum of eight cores.
If you reduce the number of total threads, GeoExpress uses fewer cores. Reduce the number of total threads when you want to perform other processor-intensive tasks on the machine that runs GeoExpress.
The following table describes switches for advanced encoding options in MG2 only.
| Switch | Value | Notes |
|---|---|---|
| -gamma | float | Changing the gamma value will affect the visual emphasis given to edges and flat color areas of the image. A lower setting creates more defined edges, while a higher setting creates softer edges. Acceptable values: 0.0 – 10.0. Default: 2.0. |
| -imageenhancement | Applies a dithering algorithm which may improve the visual quality of photographic imagery. | |
| -statistics/-stats |
Collects basic numeric statistics about the image's samples. Data collected includes the minimum, maximum, mean, and standard deviation of the samples for each band. The metadata tags that are added to the output file are: IMAGE::STATISTICS:MAX IMAGE::STATISTICS:MEAN IMAGE::STATISTICS:MIN IMAGE::STATISTICS:STANDARD_DEVIATION |
The following table describes switches for advanced encoding options that are available in MG3 and MG4 only.
| Switch | Value | Notes |
|---|---|---|
| -frequencybalance | float | Affects the visual emphasis given to edges and flat color areas of the image. A lower setting creates more defined edges, while a higher setting creates softer edges. Acceptable values: 0.0 – 10.0. Default: 2.0. |
| -kweight | float | Affects emphasis of the K band. A higher setting increases emphasis, while a lower setting increases the consistency of color between the compressed image and the original data. Acceptable values: 0.0 – 10.0. Default: 0.25. |
| -nonoptimizable | Specifies that the target MrSID file cannot be optimized at a later date. | |
| -sharpness | float |
Increasing this value increases the accuracy of rendering for sharp boundaries between different areas of an image, and reduces ringing at such boundaries. Acceptable values: 0.0 – 1.0. Default: 0.0. |
| -stripheight/-sh | sint |
MG3 and JP2 only. Affects memory usage. Increasing this value may improve runtime performance, but at a cost of requiring more physical memory. This value should be decreased when encoding very large images. Changing the strip height does not affect the quality of the output image. Acceptable values: Even integers from 2 – image’s height. Default: 64. |
The following table describes switches for advanced encoding options in MG3 only.
| Switch | Value | Notes |
|---|---|---|
| -kweight | float |
MG3 only. Affects emphasis of the K band for CMYK images. A higher setting increases emphasis, while a lower setting increases the consistency of color between the compressed image and the original data. Acceptable values: 0.0 – 10.0. Default: 0.25. |
| -onepass | Specifies the use of the one-pass optimizer instead of the two-pass optimizer. |
The following table describes switches for advanced encoding options in MG4 only.
| Switch | Value | Notes |
|---|---|---|
| -colortransform | boolean | Specifies that RGB (YIQ) Color Transform should be applied to first three bands in a multispectral image. Set to True only if first three bands are R, G and B in that order. Default: False. |
| -alphasource/-as |
Alternately
|
|
| -dynamicrange/-dr | string | Calculate dynamic range information from the image statistics and write the dynamic range to the metadata. For acceptable values, see Generating Dynamic Range Metadata. |
|
-floatingPointQuantization Precision/ -fpqp |
string | For floating point images, you can specify a quantization precision value to ensure that image data is accurate to a specific value. Enter a comma-separated list of band numbers and precision values. For more information, see Floating Point Images. |
| -floatingPointQuantizationMin/ -fpqmin | string | For floating point images, you can specify the minimum value that you want GeoExpress to keep during quantization. Enter a comma-separated list of band numbers and minimum values. For more information, see Floating Point Images. |
| -floatingPointQuantizationMax/ -fpqmax | string | For floating point images, you can specify the maximum value that you want GeoExpress to keep during quantization. Enter a comma-separated list of band numbers and maximum values. For more information, see Floating Point Images. |