Output image configuration¶
The pan-sharpened image format can be configured. Configuration options are shared with the oty orthorectification sub-commands, and default to sensible values when not supplied.
Data type and compression¶
The image data type defaults to the multispectral image data type, and can be changed with --dtype. Compression can be configured with --compress as either deflate or lzw (with any image data type), or jpeg (with the uint8 or uint16 image data types). If --compress is not specified, compression defaults to jpeg when the image data type is uint8, and to deflate otherwise. When jpeg compression is used with the uint16 data type, the image is 12 bit jpeg compressed.
Note
Support for 12 bit JPEG compression is Rasterio build / package dependent.
The next example creates a pan-sharpened image with the int16 data type, and deflate compression:
oty sharpen --pan pan_sharp/pan.tif --multispectral pan_sharp/ms.tif --out-file pan_sharp.tif --dtype int16 --compress deflate
Masking and overviews¶
Valid image pixels are masked with either an internal mask band or a nodata value. By default, an internal mask is used when the image is jpeg compressed. This avoids jpeg artefacts in invalid areas. When the image is deflate or lzw compressed, the default is use to a nodata value based on the data type. Masking behaviour can be changed with --write-mask to write an internal mask, or --no-write-mask to use a nodata value.
Internal overviews are added by default. This can be changed with --no-build-ovw. In this example, we create an pan-sharpened image with deflate compression, internal masking rather than nodata, and no internal overviews:
oty sharpen --pan pan_sharp/pan.tif --multispectral pan_sharp/ms.tif --out-file pan_sharp.tif --compress deflate --write-mask --no-build-ovw
Custom creation options and driver¶
For pan-sharpened image configurations not possible with the above options, custom creation options can be specified with --creation-option. The --compress option is ignored, and no other creation options are set by Orthority when this is supplied.
The image can be formatted as a gtiff (GeoTIFF - the default) or cog (Cloud Optimised GeoTIFF) with --driver.
This example formats the pan-sharpened image as a COG with internal masks, and specifies custom creation options for JPEG compression with a quality of 90:
oty sharpen --pan pan_sharp/pan.tif --multispectral pan_sharp/ms.tif --out-file pan_sharp.tif --write-mask --driver cog --creation-option compress=jpeg --creation-option quality=90