ROT

Description

Rotates rectangular image data in image channels between two image files or within one file. Optionally, a ground control point (GCP) segment may be rotated along with the image.

Parameters

Name	Type	Length	Value range
Input: Input raster channels	Raster port	0 - 1024
Output: Output raster channels	Raster port	0 - 1024
InputGCP: Input GCP segment	GCP port	0 - 1
OutputGCP: Output GCP segment	GCP port	0 - 1
Angle	Float	0 - 1	0 - 360 Default: 90
Center (pixel, line): X, Y	Float	0 - 2
Resampling Method	String	0 - 1	See Details Default: NEAR
Working Memory Size	Integer	0 - 1	1 - 2000 Default: 64
Report	String	0 - 192	See parameter description

Parameter descriptions

Input: Input raster channels

Optionally specifies the input channels to be rotated.

If this parameter is not specified, no input channels are rotated. Duplicate channels are NOT allowed.

If the output file does not exist, this parameter must be specified in ascending order.

Output: Output raster channels

Optionally specifies output channels to receive the rotated images.

Duplicate channels are NOT allowed.

If the output file is the same as the input file and the rotation angle (ANGLE) is 180 degrees, the output channels (DBOC) can be the same as the input channels (DBIC).

If the output file is the same as the input file and the rotation angle (ANGLE) is NOT 180 degrees, the output channels (DBOC) cannot be the same as the input channels (DBIC).

If the specified output file does not exist, this parameter will be ignored and ROT will create the channels automatically.

InputGCP: Input GCP segment

Optionally specifies the GCP segment to be rotated along with the input image.

Only the image coordinates inside the GCP segment will be rotated.

OutputGCP: Output GCP segment

Optionally specifies the output GCP segment to receive the rotated GCP data.

Angle

Specifies the clockwise angle of rotation, in degrees.

Center (pixel, line): X, Y

Optionally specifies the center of rotation, in pixel and line coordinates. If this parameter is not specified, it defaults to the center of the input image.

Resampling Method

Specifies the resampling method to use to determine the ouput pixel values.

Working Memory Size

Specifies the amount, in megabytes, of internal memory allocated to ROT.

The default is 64 MB; a typical amount of memory to allocate is approximately half of the system memory available per processing thread.

Report

Specifies where to direct the generated report.

Available options are:

• LOG: generates a report on the terminal (default)
• <modulename.RPT>: appends a report to the module's RPT file
• DISK: generates a report on file "IMPRPT.LST"

Details

ROT rotates the specified rectangular image channels (DBIC) and optionally a GCP segment (DBGC) in the input file by a user-defined angle (ANGLE), or simply rotates a GCP segment from the input file to the output file. For image rotation, the result is saved in the specified output image channels (DBOC) in the output file. If the output file is not specified, it defaults to the input file. If the output file is specified but does not exist, ROT automatically creates an output file that fits the rotated image.

This function requires a minimum of 64MB of internal memory.

You can specify the center of rotation (RCENTRE) in pixel and line coordinates. By default, the center of rotation is the center of the input image.

The RESAMPLE (Resampling Method) parameter specifies the resampling method used during rotation.

If the rotation angle is 180 degrees and the center of rotation (RCENTRE) is not specified, it will be treated as a special case and ROT will run much faster.