NAME

       i.photo.camera  - Interactively select and modify the imagery group camera reference file.

KEYWORDS

       imagery, orthorectify

SYNOPSIS

       i.photo.camera
       i.photo.camera help
       i.photo.camera group=name  [camera=name]   [--verbose]  [--quiet]

   Parameters:
       group=name
           Name of imagery group for ortho-rectification

       camera=name
           Name of camera reference file to use

DESCRIPTION

       i.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.  There are two coordinate systems: The image
       coordinate system (in pixels) and the photo coordinate system (in milli-meters). The inner
       orientation  establishes a relation between the pixels and the image coordinates with help
       of fiducial marks.

       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).

       This example is the  camera  Zeiss  LMK9  265-002A  belonging  to  the  Hellenic  Military
       Geographical Survey (HMGS) and calibrated in December 1985

       The  photo  coordinate  system  origin  is  the  so-called calibrated principal point (PP,
       Principal Point of Symmetry) which is in the center of the image.  The origin of the  axes
       is  at  the intersection of the radii traced from the fiducial marks. In the ideal case of
       no deviations in the camera (see camera calibration certificate) the center is the  origin
       and  the  values  are  0  for both X and Y of Point of Symmetry. But usually the principal
       point does not fall on the intersection of the radii at the center of  the  picture.  This
       excentricity is usually of the order of a few micrometers.

       You  are  then  asked  to enter the X and Y photo coordinates of each fiducial as follows.
       These fiducials (or reseau) marks are index marks imaged on film which serve as  reference
       photo  coordinate  system.  The  maximum  number of fiducials will determine the number of
       fiducial or reseau coordinate pairs to be entered below. The origin is the center  of  the
       image  (or  the point of symmetry) and X and Y are left-right and up-down. The order is up
       to the user, but must be kept consistent throughout the rectification process.

       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, i.photo.2image, i.photo.2target, i.photo.init

AUTHOR

       Mike Baba, DBA Systems, Inc.

       Last changed: $Date: 2010-12-22 02:05:10 -0800 (Wed, 22 Dec 2010) $

       Full index

       © 2003-2013 GRASS Development Team