AUTOMOS

Description

AUTOMOS composes a set of georeferenced images into an image mosaic, or into a series of mosaic tiles. This may include the automatic selection of cutlines and color balancing.

Parameters

Name	Type	Caption	Length	Value range
MFILE *	String	Input file name, directory, or text file	1 - 192
DBICLIST	String	List of input channels to be processed	0 - 192
MOSTYPE	String	Output mosaic type	0 - 7	NONE, PREVIEW, FULL
FILO	String	Output file name	0 - 191
FTYPE	String	Output file type	0 - 4	Default: PIX
FOPTIONS	String	Output file options	0 - 64
CLRMOS	String	Clear mosaic	0 - 3	YES, NO Default: YES
STARTIMG	String	File name of the starting image	0 - 191
RADIOCOR	String	Radiometric correction option	0 - 8	NONE, HOTSPOT, ADAPTIVE Default: NONE
BALMTHD	String	Color balancing method	0 - 10	NONE, OVERLAP, HISTOGRAM, REFERENCE, LUT Default: NONE
BALOPT	Integer	Color balancing options	0 - 4	0 -
FILI_REF	String	File name of color balancing reference image	0 - 192
LOCLMASK	String	Bitmap mask option for input images	0 - 4	NONE, BIT Default: NONE
GLOBFILE	String	Input global bitmap mask file name	0 - 192
GLOBMASK	Integer	Input mask layer in global bitmap mask file	0 - 1
CUTMTHD	String	Cutline generation method	0 - 10	MINDIFF, MINRELDIFF, EDGE, ENTIRE Default: MINDIFF
FILVIN	String	Input file name of the file containing cutlines	0 - 192
DBIV	Integer	Segment number from existing input vector cutlines file	0 - 1
FILVOUT	String	Output cutline vector file name	0 - 191
DBOV	Integer	Segment number from existing output vector cutlines file	0 - 1
DBLUTO	String	Output lookup table segment numbers	0 - 64	Default: NONE
BLEND	Integer	Blend width, in pixels	0 - 1	0 -
BACKVAL	Float	Input channel background value	0 - 1	Default: 0.0
TEMPDIR	String	Directory path name for temporary files	0 - 192

* Required parameter

Parameter descriptions

MFILE

Specifies a directory path name, image file path name, or the path name of a text file that contains input image path names. The recognized image files in the directory, image file, or text file specified for MFILE will be processed. Wildcards characters (*) and lists delimited by semi-colons can be used.

MFILE can be set in one of the following ways:

• Specify a file name or directory path and file name (for example, "irvine.pix" or "c:\data\irvine.pix"). The image file specified will be processed using the parameters set in the function.

  An image file path name value may contain an asterix (*), or "wildcard" character, that matches any substring, including an empty string.

• Specify particular file formats or all of the files in a folder (for example, "c:\data\*.pix" or "c:\data"). If this option is used, all recognized image files are processed using the parameters set in the function.
• Specify a text file referencing multiple files with different parameter settings (for example, "c:\list.txt"). This is useful if you have multiple files that require different outputs. If this option is applied, the files and parameters listed in the text file are used for processing and override the ones specified in the function.

When specifying an MFILE value:

• Specify string parameters within quotation marks.
• Do not specify numeric parameters within quotation marks.
• Note that a quotation mark preceded by a backslash is used as part of the string. For example: "ab\"c" is used as: ab"c.
• Specify only the folder in the directory path, if you want to process all of the files within the folder.

If MFILE is specified as a text file, the following general rules apply:

• Specify a .txt extension for the file containing multiple files and different parameter values.
• List each set of parameters in the given order per line.
• Use an exclamation mark (!) before writing a comment in the text file.
• Use semi-colons to delimit the parameters.
• Leave the position between the semi-colons empty (that is, ";;"), if you want the default values used. Alternatively, if there are no remaining parameters to be specified on the end of a line, you may leave it blank.

DBICLIST

Specifies the list of channels to combine into a mosaic. DBICLIST supports different input methods.

Enter one or more channel number sequences separated by commas, representing the channels in the input file that hold images to be mosaicked.

A channel number sequence is either a single positive integer or two positive integers on either side of a hyphen. The latter represents the sequence of integers from the first to the second. The number on the left side of the hyphen must be less than the number on the right side.

For example, the value "1-4,6,7" is equivalent to the channel number list 1,2,3,4,6,7.

This parameter is ignored if the value of MFILE (Input File) is a text file path name.

MOSTYPE

Specifies the type of output mosaic to create.

Valid options are:

• NONE: No output mosaic will be created
• PREVIEW: Generates a downsampled mosaic
• FULL: Generates a full-resolution mosaic

This parameter may be empty only if output cutlines or LUTs are specified, but no output mosaic is required.

FILO

Specifies the path and file name of the single file that will contain all channels of the output mosaic image.

If the mosaic image is to be output as a single file, this parameter specifies the path and file name of the file that will contain all channels of the mosaic image.

If the mosaic image is to be separated into tiles, this parameter will be used as part of the path and file name for each file that will contain all channels of one tile of the output mosaic image. For more information about tiling, see the Function Details section.

This parameter may be empty only if MOSTYPE (Mosaic Type) is empty or set to "NONE".

FTYPE

Specifies the output file format type, represented by a three-letter code. The format type must be a GDB-recognized file type.

Supported file format codes include:

• PIX: PCIDSK format
• TIF: Tagged Image File format
• XWD: X Window Dump (XWD) format

The default value is PIX.

A full list of GDB-recognized file types and their codes is provided in the 'GDB file formats' section of the CATALYST Professional online Help.

Note: Compressed output formats such as JP2 aare not supported.

FOPTIONS

Specifies the file creation options that are to be applied when creating the output file. These are specific to the file format; in each case, the default of no options is allowed. FOPTIONS can be used to specify the compression schemes, file format subtypes, and other information.

Different options are available for different file types (see the FTYPE parameter). The options are described in the 'GDB file formats' section of the CATALYST Professional online Help.

CLRMOS

Specifies whether to delete existing data from the output mosaic file before processing the mosaic.

If YES, all channels of the output file(s) that will hold the mosaic image will be initialized to zero before the image data are written to them.

If NO, new data is added to the existing file(s). The default value is YES.

STARTIMG

Specifies the file name of the image file that AUTOMOS will add to the mosaic first. By default, AUTOMOS finds the most central image, and increases the mosaic size by adding the next closest image.

Because the starting image is also the starting point for color balancing operations and cutline selection, it is generally advisable to use a central image with good radiometry.

RADIOCOR

Specifies the normalization filter to apply to the orthorectified images before they are compiled into a mosaic.

The following values are supported:

• HOTSPOT: removes hotspots from the images
• ADAPTIVE: balances the brightness and contrast in the images
• NONE: does not apply normalization filter

BALMTHD

Specifies the method to use for color balancing across images to be mosaicked.

The following values are supported:

• NONE: no color balancing is performed

• OVERLAP: color balancing is applied based on matching overlapped areas of the input images.

  This option requires sufficient overlap (larger than 10 percent) between each pair of adjacent input images with good quality georeferencing. It is not effective if the same features in overlapping images appear different due to variations in illumination and view direction between images.

  If you use this color balancing method and are specifying a local (LOCLMASK) or global mask (GLOBMASK), your mask must have some pixels within the overlap area in order to affect the output.

• HISTOGRAM: color balancing is applied sequentially, by matching the input image histogram with the target mosaic image.

  The HISTOGRAM option can include histogram trimming, which requires that a trim percentage value be given through the BALOPT (Color Balancing Options) parameter, along with the perferred match area size. This option works in a sequential manner, matching each input image with the destination mosaic image.

  HISTOGRAM also supports the use of exclusive masks.

  Because this option does not require very precise georeferencing and overlap, it may be beneficial when working with larger data sets.

• REFERENCE: color balancing is applied by matching the input image histogram with the specified reference image.

  The reference image file is specified by FILI_REF; this option matches the histogram of each input image with that of a reference image.

  REFERENCE also supports the use of exclusive masks.

  Because this option does not require very precise georeferencing and overlap, it may work better with image sets having consistent radiometric distribution.

• LUT: color balancing is applied based on the input LUT segment numbers.

  Specify the input LUT segment numbers using BALOPT (Color Balancing Options).

BALOPT

Specifies options for color balancing. This parameter applies when the BALMTHD parameter is set to HISTOGRAM, REFERENCE, or LUT.

If BALMTHD (Color Balancing Method) is set to HISTOGRAM, the histogram area and trim settings can be adjusted by using BALOPT (Color Balancing Options) to indicate the area multiple and the trim percentage. In this case, two input values are required:

• Area multiple: Must be a value greater than 1 representing the percentage of the area in the mosaic file that will be used to calculate the color balancing histogram. The row and column dimensions of the input image are multiplied by this value to define the dimensions of a subregion of the target image for which the target image histogram that is used in the histogram matching operation is computed. The subregion is positioned within the target image such that its center is at the georeferenced center of the input image. The default value is 3.
• Trim percentage: A number representing the percentage removed from the upper and lower parts of the histograms range. Trimming means to ignore the specified trim percentage of the total histogram area from the ends of both tails in a gray-value histogram when matching with another target histogram. Trimming will be applied on both the input image and the target image. The default value is 2 percent.

If BALMTHD is set to REFERENCE, use BALOPT to specify reference image channels.

If BALMTHD is set to LUT, use BALOPT to specify input LUT segment numbers.

FILI_REF

Specifies the file name of the reference image file to use when BALMTHD (Color Balancing Method) is set to REFERENCE.

It is not necessary for the reference image to have the same resolution or projection as the input images. When the reference image has different projection from that of the input images, the reference image can be used as long as neither is in the PIXEL, METER, or FOOT projection.

By default, the reference image channels appear in the same order as the channels specified in DBICLIST; that is, the i'th channel in the reference image will be matched with the i'th channel in the DBICLIST in input images. You may, however, use BALOPT (Color Balancing Options) to re-map these channels.

When re-mapping channels , a list of re-mapped channels are specified through the BALOPT parameter. The i'th number in this list is the channel that will be matched to the channel whose number is the i'th number in DBICLIST.

LOCLMASK

Specifies whether a bitmap in an input file will be used as an exclusion mask for mosaicking.

If LOCLMASK is set to BIT, the individual bitmap in each input image file will be used as an exclusion mask. If the file contains multiple bitmaps, the last one will be used.

An exclusive individual bitmap layer is contained in each input image file with a valid georeference. The values in a bitmap are either 1 or 0, represented by each bit, and are referenced to each pixel in this image. When processing an image with the individual bitmap consideration, an image pixel with a relevant bit value of 1 will be excluded; if the bit value is 0, that pixel will be used.

The bitmap exclusion is used in cases where some surfaces (for example, the surface of water bodies) can appear radically different in the orthorectified and reference images due to ephemeral phenomena such as specular reflection of sunlight. Another example that may be relevant in a very large scale application is a parking lot that is full of cars in one image and empty in another.

GLOBFILE

Specifies the path and file name of the global exclusion mask bitmap file.

If this parameter is set to a file name, the bitmap in that file will be used as an exclusion mask for mosaicking. If the file contains multiple bitmap layers, use the GLOBMASK (Global Mask) parameter to specify the layer number of the bitmap to be used.

GLOBMASK

Specifies the layer number of a bitmap file to use for mosaicking. This parameter is used only if GLOBFILE (Input Global Bitmap Mask) is specified and the global bitmap mask file contains multiple bitmap layers. Within a bitmap layer, all the image pixels with a relevant bit value of 1 will be excluded, while pixels with a bit value of 0 will be used in the processing.

CUTMTHD

Specifies the method used to collect cutlines for mosaicking.

The folllowing values are supported:

• MINDIFF: specifies the "minimum difference" option

  This method applies to most mosaicking projects. The algorithm determines a cutline in each overlapped area between two adjacent images that contain the minimum differences of gray values at the same locations of the region.

• MINRELDIFF: specifies the "minimum relative difference" option

  The algorithm determines a cutline in each overlapped area between two adjacent images with minimum differences of gray-value gradients at the same locations of the region. This approach is most effective in cases where the display of the same sections of a scene appear very different in different images.

• EDGE: specifies the "edge feature" option

  This algorithm uses a combination of Minimum Difference and Minimum Relative Difference to determine the optimum location for the cutlines. This approach is most effective in urban area mosaicking, or in a scene with many linear features. The objective of the EDGE method is to avoid placing cutlines across linear features.

• ENTIRE: specifies that the entire images will be added to the mosaic. This option is used to mosaic images that do not overlap. The algorithm uses the four corner coordinates of the images as the cutlines, according to the stacking order.

FILVIN

Specifies the input file or layer containing vector cutlines.

Vector data describing cutlines are read from the specified file and used in the mosaic composition. If input image files do not contain cutlines, new cutlines are generated according to the value of the CUTMTHD (Cutline Generation Method) parameter.

The number of the vector segment in the specified file from which the cutlines are to be read is specified with in DBIV (Input Vector Segment).

DBIV

Specifies the number of the vector segment containing cutlines to use for mosaicking, from the input vector file defined by FILVIN (Input Vector File).

FILVOUT

Specifies the path and file name of the file in which new cutlines will be saved.

If the cutlines are to be stored in an existing vector segment, the number of that segment must be specified with the DBOV (Output Vector Segment) parameter.

DBOV

Specifies number of the vector segment in which new cutlines will be saved, from the output vector file defined by FILVOUT (Output Vector File).

If FILVOUT is specified and this parameter is not, a new vector segment will be created to hold the new cutlines.

DBLUTO

Specifies the segment numbers in an output lookup table (LUT) in which to store image color balancing information.

If color balancing is requested (see BALMTHD), this parameter allows the user to store the LUT for every image channel.

To create new LUT segment numbers to store the LUTs, set DBLUTO="CREATE" or "0".

To overwrite existing LUT segment numbers, set DBLUTO equal to the segment numbers.

If one or more segments numbers are specified, the format of the output files must PCIDSK.

BLEND

Specifies the perpendicular distance, in pixels, from the cutlines over which image blending will be performed.

Image blending means to average each pixel gray value in the blending strip along a cutline from both overlapped input images with a weight. The weight is the perpendicular distance between the pixel and the strip edge divided by 2 times of the blend width; the new blended pixel value is the weighted average of the two overlapped images.

If BLEND is empty, an optimum value (up to a maximum of 5 pixels) is estimated and used.

BACKVAL

Specifies the background value of the input image channel.

OrthoEngine uses a background value of zero for orthorectified or geometrically corrected images, so the Mosaic Area also has a background value of zero by default. However, images orthorectified or geometrically corrected outside of OrthoEngine may have a background value other than zero.

Pixels having the specified background value within an input orthorectified image are interpreted as non-image values; this ensures that the output mosaic contains only valid data from the input images.

TEMPDIR

Specifies the path name for temporary files used in the mosaicking process.

If TEMPDIR is empty, the temporary files are created in the working directory.

Details

AUTOMOS composes a set of georeferenced images into an image mosaic. This may include color balancing and the selection of cutlines. Note that any changes in color balancing methods used will affect cutline generation and the final mosaic result.

Specifying input text file parameters

If the value of MFILE (Input File) is a text file, the files and parameters values listed in the text file will be used as input. The parameters in the text file must be delimited by semi-colons and appear in the following order:

[FILE] ; [DBICLIST] where DBICLIST is optional

For example:

"C:\pci\irvine.pix"; "1,2,3"

In the example above, the input channel list (1,2,3) is specified in the text file. If the input channel list is not given, it will be taken from the DBICLIST parameter.

Specifying output text file parameters

If the parameter FILO (Output File) is set to an existing text file, it can be used to create more than one mosaic at a time. You can specify already existing mosaic files, or you may create new tiles by specifying the upper-left (ULX, ULY) and lower-right (LRX, LRY) boundaries for each output mosaic tile.

To create output mosaic tiles:

1. Set the FILO parameter to a text file.

   FILO=tilespecs.txt

2. Create a text file that contains one line for each tile output file that you want AUTOMOS to create or update.

   Each line of the text file uses the same convention of specifying a file name and, optionally, specifying bounds. The parameters in the output text file must be delimited by semi-colons and appear in the following order:

   [FILE];[ULX];[ULY];[LRX];[LRY]

Example

The following example text file content specifies two output mosaics that are at the same x-position and are adjacent to one another in the y-dimension.

"C:\pci\Mosaic1.pix"; 350000; 4800000; 370000; 4750000
"C:\pci\Mosaic2.pix"; 350000; 4750000; 370000; 4700000

Example

Compose a mosaic from the image data in directory rectified.

EASI>MFILE = "rectified"
EASI>DBICLIST = "1,2,3,4"        ! Specifies the input channels list
EASI>MOSTYPE = "FULL"            ! Create full resolution mosaic
EASI>FILO    = "mosaic_out.pix"  ! Specifies the generated file
EASI>FTYPE   =                   ! Uses the PIX default
EASI>FOPTIONS= "PIXEL"           ! Store the mosaic in pixel-interleaved format
EASI>CLRMOS  = "YES"             ! Clears the mosaic file before starting
EASI>STARTIMG = 
EASI>RADIOCOR = "NONE"
EASI>BALMTHD = "NONE"
EASI>BALOPT  = 
EASI>FILI_REF = 
EASI>LOCLMASK = 
EASI>GLOBFILE = 
EASI>GLOBMASK = 
EASI>CUTMTHD = "MINDIFF"
EASI>FILVIN  = 
EASI>DBIV    = 
EASI>FILVOUT= 
EASI>DBOV    = 
EASI>DBLUTO  = "2"               ! Generates to LUT segment 2
EASI>BLEND   = 
EASI>BACKVAL = 
EASI>TEMPDIR = 

EASI>RUN AUTOMOS