USGS MIPS Masterctl Documentation

USGS MIPS Masterctl Documentation

This program creates a control point file that can be used to help register one image (referred to as the slave image) to another image(referred to as the master image). The control point file created by this program will contain uniformly spaced control points, which are solely based on information in the master image only, automatically selected on how busy different image sub-areas are with respect to the image itself. Automatically selecting control points this way not only allows any number of points to be selected within an image but they are selected in a way that the chances of finding another pixel in the slave image to correspond with the same one in the master image are better. The user can specify an upper limit on the number of control points to be written to the control point file. Once this master control point file is created, it can be used as input into the program TUNECTL.

Files

This program requires as input one to two unsigned 8-bit image files and generates a control point file. The first input file is the master image to be processed while the second is an optional work file.

Parameters

NROW and NCOL: These parameters are used to select the number of control points in the row and column directions. Selecting Ncol to be greater than Nrow would result in having more control points selected in the column direction than in the row direction. MASTERCTL will attempt to select a total number of control points depending on the values of these two parameters where (NROW X NCOL) is an upper limit on this number(e.g., setting Nrow to 4 and Ncol to 5 will result in no more than 20 control points being written to output file). Values entered for Nrow and Ncol must be greater than or equal to 2. The defaults for both of these parameters is 10.
SIZE: This parameter is used to select the size of the NxN standard deviation filter used in the algorithm of selecting control points from the image. Setting Size to 7 sets the size of the deviation filter to 7x7 which is a box of 7 lines by 7 samples. The "best" Size that can be selected for optimization can only be attained through a repetitive process where the final geomed slave image has been created and can be interpreted by the user. Note that the value entered for this parameter must be an odd number and must also be greater than or equal to 3. The default Size is 31.
TOLERANCE: This parameter is used to select the tolerance to be used in accepting control points. Selecting a high tolerance may result in fewer selected control points and vice-versa. The default tolerance is 7.5.
HIGH or CENTER: These options used to select which pixel to use in the selection of a control point. The High option uses the pixel with the highest variance while the Center option uses the pixel nearest the center of the search area. The default option is High.
MIN and MAX: These parameters are used to select a minimum valid low dn and a maximum valid high dn to be used in calculations. For the selected Min, all dns below this number will not be used in the calculations for the filter. For the selected Max, all dns above this number will not be used in the calculations for the filter. Values entered for both Min and Max have minimum allowed values of 0 and maximum allowed values of 255. Min defaults to 1 while Max defaults to 254. Note that Min must be less than Max.