Section 3 - Program Interface, Interaction and Warnings

Configuration File ('bigmo.cfg')

Q) What configuration file parameters are available and what does each one do?
A) A documented version of the 'bigmo.cfg' configuration file is available from the download page.
Q) Is it possible to have more than one 'bigmo.cfg' configuration file? Where does OrthoVista look to find this file?
A) It is possible (although confusing) to utilize multiple configuration files. Orthovista searches sequentially for the configuration files which includes searching: environment variable path, current directory, directory from where program was run, and default installation directory. It uses the first file encountered during this search sequence.

"User Region" Data

Q) Under the menu item, "User Definition", there is an option called "Load Region Definition", what is this used for?
A) OrthoVista can now load an ArcView Shape file to specify 'exclusion' areas for balancing. This way things like water areas can be ignored during balancing computations. The "Load Region Definition" does NOT do that - it only loads a Shape file for display on the screen. (This is useful for viewing the shape file superposed on the imagery). In order to actually use it in processing, you have to specify the exclusion file in the balancing options in the processing dialog.
Q) How are "User Data" utilized?
A) There are two uses for the "user data"
1) The most significant use is to exclude pixel data from radiometric computations. Part of Processing-HotSpot-Options dialog.
2) It can also be used to select images and/or tiles for processing - like the way a tile definition file can be used to select images for processing - i.e. Process-Select-Tiles-(by...) selection box.
More details for each are explained in the latest (MSWord) version of the manual.

Processing Control

Q) Is "batch" style processing supported?
A) No, not as of current Version (2.2.2).

Warning and Error Messages

Q) "Warning, image balancing fit failed, using original image."
A) If OrthoVista can't find enough image pixel data (non-background pixels) required to fit the balancing model, then it prints this warning message, and does NOT balance this image.
One way to address this situation is to increase the number of samples used in the balancing computation by changing the Grid Size Option in the processing dialog, single image method options. If the Grid Size is already set to a reasonable value (e.g. perhaps 30 to 50), then this warning may indicate that the input image is lacking meaningful image data (e.g. all background pixels - no or very little image data). Note that setting the background checking tolerance too strict (e.g. too large a minimum value and/or too low a maximum value) can exacerbate this problem.
Q) During computation we get the following error message. However computation still seems to proceed correctly. Should I be concerned about this?
Warning:Assert: "c+num<=width()" in imgcached.cc
A) Normally an "ASSERT" message indicates a very serious software problem. Typically, we would expect an ASSERT message to be fatal. However, this particular case seems to occur occasionally. We have not isolated the conditions which cause it - it may be related to use of metadata from a previous computation. If you encounter this, try deleting all metadata files, run the block again "from scratch".