TRANSFRM

Compute Registration Transformation

Environments	EASI
Sections	Description Parameters Parameter Details Details Example Related

Description

Combines transformation matrices calculated from the REG program. These coefficients were calculated from GCP segments determined by both hand (coarse registration) and auto_reg (fine registration). Both the forward and backward matrices are stored in a segment as a text field.

The files TRNS_1 and TRNS_2 must be created by GCPREP by setting the report string.

Parameters

TRANSFRM is controlled by the following global parameters:

Name	Prompt	Type	Length
FILO	Database Output File Name	Char	1 - 192
TRNS_1	First transformation filename	Char	1 - 192
TRNS_2	Second transformation filename	Char	1 - 192
REPORT	Report Mode: TERM/OFF/filename	Char	0 - 192
MONITOR	MONITOR mode: ON/OFF	Char	0 - 3

Parameter details

FILO

Specifies the name of the PCIDSK file which will hold the forward and backward transformation coefficients in a segment.

EASI> FILO = "Output filename"

TRNS_1

Specifies the filename of the text file which holds the first set of transformation coefficients from the first registration. This file must be created using GCPREP and be first order.

EASI>TRNS_1 = "trns1.rpt"

TRNS_2

Specifies the filename of the text file which holds the second set of transformation coefficients from the second registration. This file must be created using GCPREP and be second order.

EASI>TRNS_2 = "trns2.rpt"

REPORT - Optional

Specifies where to output the report to.

MONITOR - Optional

Program progress can be monitored by printing the percentage of completed processing in odometer fashion. A system parameter, MONITOR, controls this activity:

EASI>
MONITOR="ON"           | turn monitor ON  (default)
EASI>MONITOR="OFF"          | turn monitor OFF (recommended if
                            | running in batch/background mode)

Details

The TRANSFRM program is used to combine transformations calculated by the REG or REGPRO programs. After the image goes through a registration, use GCPREP to save a report out to a file. This file should be TRNS_1 for the first registration and TRNS_2 for the second registration. The TRNS_1 file should contain a first order transformation, and the TRNS_2 file should contain a second order transformation. Using these two reports, the backward transformation is read in and the forward transformation is calculated. These two transformations are then placed into the following format:

Forward Transformation: A00;A01;A10;A11; Backward Transformation: B00;B01;B02;B03;B04;B05;B10;B11;B12;B13;B14;B15;

This string is then saved to a new text segment on FILO for later retrieval by NEWGCP.

ALGORITHM

TRANSFRM will simply extract the two transformations from the text files TRNS_1 and TRNS_2 and will combine these transformations to get the backward transformation. The backward transformation matrix is then inverted to get the forward transformation matrix.

Example

Two files are required in the current user directory: TRNS_1 and TRNS_2. TRANSFRM will then read in the transformations and calculate the total forward and backward transformations to store in a string. TRANSFRM will then save the text string to FILO in a new text segment.

EASI> FILO = "out.pix"
EASI> TRNS_1 = "trans_1"
EASI> TRNS_2 = "trans_2"
EASI> r transfrm

Related topics

The following is a list of related topics.