.. _image_mosaic:

image_mosaic
------------

The program ``image_mosaic`` aligns multiple input images into a single
output image. Currently it only supports a horizontal sequence of images
such as scanned Corona images. An example of using this tool is in
:numref:`kh4`.

Usage::

     image_mosaic [options] <images> -o output_file_path

Command-line options for image_mosaic:

--t_orientation <horizontal>
    Specify the image layout.  Currently only supports horizontal.

--reverse
    Mosaic the images in reverse order.

--rotate
    After mosaicking, rotate the image by 180 degrees around its
    center.

--rotate-90
    After mosaicking, rotate the image by 90 degrees clockwise
    around its center.

--rotate-90-ccw
    After mosaicking, rotate the image by 90 degrees counter-clockwise
    around its center.

--use-affine-transform
    Solve for full affine transforms between segments instead of a
    simpler rotate+translate transform.

-o, --output-image <string>
    Specify the output file path. Required.

--overlap-width <number-of-pixels (default: 2000)>
    The width of the expected overlap region in the images, in
    pixels.

--blend-radius <number-of-pixels>
    The width in pixels over which blending is performed. Default
    is calculated based on the overlap width.

--band <integer (default: 0)>
    Specify a band to use for multi-channel images.

--ot <type (default: Float32)>
    Output data type. Supported types: Byte, UInt16, Int16, UInt32,
    Int32, Float32. If the output type is a kind of integer, values
    are rounded and then clamped to the limits of that type.

--input-nodata-value <double>
    Override the input nodata value.

--output-nodata-value double
    Specify the output nodata value.

--ip-per-tile integer
    How many interest points to detect in each :math:`1024^2` image
    tile (default: automatic determination).

--output-prefix <string>
    If specified, save here the interest point matches used in
    mosaicking.

--threads <integer (default: 0)>
    Select the number of threads to use for each process. If 0, use
    the value in ~/.vwrc.
 
--cache-size-mb <integer (default = 1024)>
    Set the system cache size, in MB.

--tile-size <integer (default: 256 256)>
    Image tile size used for multi-threaded processing.

--no-bigtiff
    Tell GDAL to not create bigtiffs.

--tif-compress <None|LZW|Deflate|Packbits (default: LZW)>
    TIFF compression method.

-v, --version
    Display the version of software.

-h, --help
    Display this help message.