This is not a command in itself, but an option to the command i.ortho.photo

## NAME

photo.camera - An imagery function that creates or modifies entries in a camera reference file.
(GRASS Image Processing Program)

## SYNOPSIS

photo.camera option must be selected from the GRASS Image Processing Program i.ortho.photo .

## DESCRIPTION

photo.camera creates or modifies entries in a camera reference file. For ortho-photo rectification, a camera reference file is required for computation of scanned image to photo-coordinate transformation parameters.

The first prompt in the program will ask you for the name of the camera reference file to be created or modified. You may create a new camera reference file by entering a new name, or modify an existing camera reference file by entering the name of an existing camera file.

After entering the camera file name, following menu is displayed:

Please provide the following information

    	CAMERA NAME:               camera name______
    	CAMERA IDENTIFICATION:     identification___
    	CALIBRATED FOCAL LENGTH mm.:_________________
    	POINT OF SYMMETRY (X)   mm.:_________________
    	POINT OF SYMMETRY (Y)   mm.:_________________
    	MAXIMUM NUMBER OF FIDUCIALS:_________________

       AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
                   (OR <Ctrl-C> TO CANCEL)

The camera name and identification describe the camera reference file. The calibrated focal length and the point of symmetry are used in computing the photo-to-target transformation parameters. These values should be entered from the camera calibration report (usually available from the photograph supplier). The maximum number of fiducials will determine the number of fiducial or reseau coordinate pairs to be entered below.

You are then ask to enter the X and Y photo coordinates of each fiducial as follows. On this screen you should enter the fiducial or reseau photo-coordinates as given in the camera calibration report. The X, and Y coordinates are in milli-meters from the principle point.

Please provide the following information

    	Fid#	FID ID		  X          Y

    	1__	_____		0.0___	0.0___
    	2__	_____		0.0___	0.0___
    	3__	_____		0.0___	0.0___
    	4__	_____		0.0___	0.0___
    	5__	_____		0.0___	0.0___
    	6__	_____		0.0___	0.0___
    	7__	_____		0.0___	0.0___
    	8__	_____		0.0___	0.0___
    	9__	_____		0.0___	0.0___
    	10_	_____		0.0___	0.0___

    		     next:  end__

         AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
                        (OR <Ctrl-C> TO CANCEL)

The input display is repeated until the number of MAXIMUM FIDUCIALS is reached.

## SEE ALSO

i.ortho.photo
photo.2image
photo.2target
photo.init

## AUTHOR

Mike Baba, DBA Systems, Inc.

Last changed: $Date: 2002/01/25 05:45:34 $