VrOrtho
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ON-LINE REFERENCE DOCUMENTATION CARDINAL SYSTEMS, LLC 386-439-2525 |
VR ORTHO (vrortho.exe) |
Type: Stand-alone Application
Current Release: 1.0
Orthophoto Generation Application.
This application will create ortho rectified images from multiple raw input images. VrOrtho will accept TIFF, JPEG, MrSID, and JPEG200 image formats as input, and will output images in TIFF or JPEG format.
The ortho rectification process consist of taking standard perspective images without uniform scale, and transforming them into geographically referenced images with the perspective removed to provide uniform scaling. The ortho images contain geographic referencing in the form of TIFF world files with a .tfw extension, GeoTIFF tags inside a TIFF file, or as JPG world files with a jgw extension. The contents of the world files and the GeoTIFF tags contain the ground coordinate of the upper left corner of the image, and a pixel size in ground for the x and y direction. When used on a standard aerial mapping job, the ortho process results in a series of overlapping ortho images. The ortho images can then be brought into a mosaicing application such as VrMosaic to tie the orthos together into a seamless image mosaic.
In order to perform the ortho rectification process, VrOrtho must have a DTM ground surface for the area to be rectified, and must have images that have been fully oriented. The DTM ground surface may be computed from standard VrOne vector files, containing points and break lines, or may be loaded from a VrOne surface file. If the DTM ground surface is specified as a VrOne vector file with points and break lines, then the surface will be computed as needed directly from the VrOne file(s). If a surface file is used, then the surface is loaded directly from the file, potentially saving a significant amount of processing time.
The image orientation process may be performed completely inside VrOrtho, or can it can be imported from other sources. The two orientation steps required are interior orientation and exterior orientation. Interior orientation is the process of calibrating images to known fiducial locations. Interior orientation is available inside Image Utility, VrTwo orientation, and VrOrtho. When dealing with large numbers of images, Image Utility provides a method for automatic interior measurement. VrOrtho will automatically recognize interior orientations that have been performed with VrTwo orientation or Image Utility. Exterior orientation is the process of computing the camera station location and rotation for each image. Exterior orientations can be imported from VrTwo Orientation, Aerial Triangulation software, or may be computed inside VrOrtho using single image resection. Single image resection consists of identifying at least 3 known ground location in the image, and a ground control file is required for this step.
Once the images have been orientated and a ground surface defined, VrOrtho is ready to generate the output ortho images. This process is done in a batch mode where one or more input images are selected, and then a single output ortho image is created for each input image. By default, each output ortho image will cover the entire area of its corresponding input image. In many cases, the raw input images will have unneeded image data around the edges of the image. It is possible to change the default settings to eliminate the extra image data so the output orthos only contain the relevant portion of the input image. If the ortho images will be used in a mosaicing process, the ortho areas should be defined so that there is sufficeient overlap between adjoining images.
The image on the left below shows a typical aerial image with fiducials and data strip information on the outside of the image. The yellow line represents the area that will be used when creating the final ortho image after changing the VrOrtho default settings to eliminate extra image information. The image on the right is the output ortho image created from the input image.
In addition to using default settings to define the ortho areas for the images, VrOrtho also provides a ortho area editing application that allows a user defined ortho area for each input image. Using the ortho area editor, any portion of the input image may be selected, included polygon shaped areas.
Before creating the final ortho images there are several output options to consider. These include the output pixel size in ground, background colors, and handling of pixels that fall outside the DTM surface area. These options are discussed in more detail in the reference section.
This is an example workflow using Vr Mapping software to ortho images.
- Obtain raw photos in digital form.
- Create a new project using VrOrtho and define project settings and add raw photos to project.
- Perform interior orientation on images using VrOrtho if they have not already been oriented.
- Perform exterior orientation on images using VrOrtho single photo resection or by importing exterior orientation data.
- Define ortho areas using default settings or by using ortho area editor.
- Define output pixel size.
- Create ortho images.
- The ortho images are now ready to be used by the VrMosaic application to define seam lines and create final output mosaic images
VrOrtho will start by opening the Main Window, the Ortho preview window, and the ortho status window
Starting an Application (Command)
Pulling down a menu and selecting an item may start commands. Commands may also be started from a key-in using the command name. Each command name is the first three letters of the first two words on the pull down. For example: The command name for Open Project is OpeProj If this rule is not followed the correct key-in is listed in parenthesis in the pull down menu after the command.
The Main Window
The Main Window in VrOrtho contains the command pull down menus, a key-in area, two information areas, a progress bar and the coordinate display.
Commands names may be typed into the key-in area at almost any time.
On the border of the Main Window is shown the
active project.
The Image Status Window
The Image Status windows display a current status for each input image. This window can also be used to start the Interior, Orientation, Single Image Resection, and Define Ortho Area commands by highlighting a single image and pressing the appropriate button.
The Ortho Preview Window
The Ortho Preview Window displays a preview of the output ortho image areas and of the ortho images if they have been generated. This window can be used as a tool to quickly verify that ortho area definitions are defined correctly. The original input image bounds and the DTM surface boundary are also displayed. The “Process DTM” can be used to force the currentlt defined DTM surface to be processed, allowing the DTM boundary to be displayed. This window may used to zoom and pan around the the image outlines. Use the Page Up and Page Down keys to zoom out and in, and use the arrow keys to pan. The icons in the lower right corner of this window may also be used for zooming.
The “Settings” button will display the following dialog:
Show Output Ortho Images
Select this option to display the ortho images in the preview window.
Show Input Image Names
Select this option to display the names inside the upper left corner of each input image boundary.
Pen number for Image Edges
Controls the color used to display the input image boundaries. The color is taken from the currently configured pen table for VrOne.
Pen number for Image Names
Controls the color used to display the input image names. The color is taken from the currently configured pen table for VrOne.
Pen number for Ortho Areas
Controls the color used to display the output ortho areas. The color is taken from the currently configured pen table for VrOne.
Pen number for DTM Boundary
Controls the color used to display the DTM boundary lines. The color is taken from the currently configured pen table for VrOne.
Project setup consist of creating a new project file, and defining
the project parameters. Before creating a project there may be a few steps that
need to be taken. These steps depend on how the image orientation will be
defined. If a camera definition file has not been defined yet then it should be
created first using the Camera->New Camera. If importing interior
orientations form VrTwo or Image Utility, then a camera file should already
exist.
If you will be
importing exterior orientations, then no other step is required before starting
the project. If single image resection will be used to compute exterior
orientations, then a coordinate file must be defined. If you do not already
have a VrOne compatible coordinate file (.cor
extension), one can be created using the Ground Control->New Coordinate File
command.
The new ortho project
is created by selecting Project->New Project command. See the command reference
section for detailed explanations of project settings.
After the project setup
has been completed, use the Create->Create Orthos
command to generate the output ortho images.
File Menu
è Open Status
Window
Open the Image Status window
if it has been closed.
è Open Overview
Window
Open the Ortho Overview window
if it has been closed.
è Create Image
Pyramids
Allows image pyramids to be
create in a batch mode. Image pyramids are stored for each image that is displayed
by Vr Mapping software. The image pyramid provide
overviews at different image resolutions allow fast image display at all zoom
levels. Normally image pyramid are created as needed by VrOrtho, and this
option should not need to be used.
Select whether or not you want
to force exsting pyramid files to be overwritten with
new files. This can be useful if the image pyramids are out dated or corrupted.
The following dialog is then displayed.
Press OK to start creating
image pyramid files for all input images in the project.
è Exit
Exits VrOrtho
Camera Menu
è New Camera
Display a dialog box that
allows a new camera definition file to be created. A dialog box will be shown
so the camera settings can be edited.
Use your camera calibration to
enter all information about the camera being defined. Each input image in the
VrOrtho project will be assigned to a camera file (usually all images in a
single project will share a single camera file).
è Edit Camera
Display a dialog box that allows
a camera definition file to be selected. A dialog box will be shown so the
camera settings can be edited. (See New Camera for details)
Camera Menu
è New Coordinate
file
Display a dialog box that
allows a new coordinate file to be created.
Select the desired layout format and units for the ground control file. You can usually leave the default settings. After defining these settings, the coordinate definition dialog will be displayed.
Use
this dialog to define any ground control points that fall on the images being orthoed.
è Edit
Coordinate file
Display a dialog box that
allows a coordinate file to be selected. A dialog box will be shown so the
coordinates can be edited. (See New Coordinate File for details)
Project Menu
è New Project
Display a dialog box that
allows a new project file to be created. A dialog box will be shown so the
project settings can be edited.
The
right side of the dialog displays the input images for the current project.
These images may be defined in VrOrtho using the Define Images… button, or the
list of images may be imported from an Image Utility project.
The
following dialog is displayed if “Define Images…” is pressed.
Dialog Features
The dialog allows all images
to be added to the project and to be defined. Pressing the “Add Photos” button
will display a dialog that allows one or more images to be selected and added
to the project. Pressing the “Delete Photos” button will delete all currently
highlighted photos. Pressing the “Hide Folders” button will hide the folder
locations of the image names and camera names. The “Hide Folders” button will
change to “Show Folders” when pressed, and then can be used to display the
folder locations again.
In order to define a setting
for all images, set the appropriate value and then press the “Apply To All” button next to the setting. In order to define a
setting for individual images, highlight the images first, then
press the “Apply” next to the setting. The currently defined settings are
applied to new photos as they are added to the project.
Project cameras –
Multiple cameras may be defined for a project. Use the “Add” button to add
cameras to the project (the camera definition file must already exists). Use the “Delete” button to remove the currently
highlighted camera from the project.
Film strip location – The
image film strip location can be set to Left, Right, Top, or Bottom.
Photo pixel size (mm) –
This setting is the pixel size in millimeters for the image.
Photo Name Separator
Character, Strip Chars, Photo Chars –
These three settings define how the image name is interpreted to produce a
Strip and Photo number.
If the “Import ImageUtil…” button is pressed you will prompted to select
an existing Image Utility (.iup) file. All input images
defined in the Image Utility project will be imported into the VrOrtho project.
You can use the “Define Images…” button to verify that the images have been
imported with the correct settings.
The
project dialog is divided into four tabs. General, Input,
Output, Ortho Area.
General Tab
The
general tab provides general project settings. The following controls are
displayed:
Project Name
Displays the file name for the current project.
Coordinates
Displays the coordinate file for the current project. This can be left blank if importing exterorior orientations.
Auto minimize windows
If checked, all VrOrtho windows will be minimized when ortho processing begins. A percentage complete will be displayed on the minimized taskbar button. If using Windows XP, you may have to turn off taskbar button grouping to see status.
Create ortho information file
If checked, an ortho information file will be created for each ortho image. This file will have the same name as the ortho image, but will have a .voi extension. The information file is an ASCII file that contains information about the processing parameters that were used to created the ortho image (Resampling mode, DTM source, etc.")
Append to log file
If checked, the vrortho.log file will be appended to for each run. Otherwise, the log file will be cleared each run.
Copy inner observations
If this option is set to yes, an image with no observations will inherit the observations from the first image in the image list.
Input Tab
The
input tab provides settings to define input data:
Use DTM Surface file
If checked, then a surface file will be used for the DTM surface during ortho generation.
DTM Surface file
If a Use Dtm surface file is checked and a valid surface file is specified here, it will be used instead of reading the VrOne DTM data. This can result in much faster DTM processing times.
DTM Source
Select the DTM source files. Use the “…” button to display the files selected. Use the Add and Remove buttons to add or remove VrOne vector files to the list.
Create surface file if it does not exist?
Creates the DTM surface file from the VrOne vector data the first time the DTM surface is processed. This is only relevant if Use DTM surface file is on. If checked, then DTM source data must be available.
DTM Extents
Defines how much of the DTM area to compute when creating orthos. This is only when not loading a surface file. If set to full the entire input DTM area is computed. This will only be computed once before ortho output begins. If set to Ortho area only, only the area needed for the image being processed will be computed. A new surface will be computed for each output ortho image.
DTM Points layer(s)
Defines the VrOne layers that contain points to be used for the computation of the DTM surface.
DTM Breaklins layer(s)
Defines the VrOne layers that contain break lines to be used for the computation of the DTM surface.
Input minimum Z
Any points with a Z lower than this will not be added to DTM. This does not apply when reading an existing surface file.
Input maximum Z
Any points with a Z higher than this will not be added to DTM. This does not apply when reading an existing surface file.
Excluded points file
If this is set, excluded points will be written to this file, one per line in comma separated format.
Output Tab
The
output tab provides settings to define how the output ortho images are
generated:
Resample Mode
The resample mode is used when creating the output orthophoto. Bicubic is the slowest mode but normally results in the best output image.
Pixel Size (ground)
This is the pixel size of the output orthophoto. It does not have to be the same size as the input photo pixel size. This value is entered as ground units.
Background Pixel Mode
This mode determines the action to take when a pixel to be resampled falls outside the DTM area. Either the “Approximate Z” will be assigned and the pixel will be resampled or the target pixel will be assigned the value specified in the “Background Pixel Color”.
Approximate Z
If the Background Pixel Mode is set to 'Use approximate Z value' this elevation will be used for pixels that fall outside of the DTM area when resampling.
Background Pixel Color
If the “Background Pixel Mode” is set to “Fill with Background Pixel Color” this pixel (color) value will be used if a new pixel to be resampled falls outside the DTM coverage coverage.
Exclude Background Color?
If checked, valid image pixels that are the same color as the Background pixel color will be written with a slightly different color
to ensure that no image pixels are the same color as the Background pixel color. This can be helpful when doing blending with VrMosaic.
Outside Limits Pixel Color
This pixel (color) value will be used if a new pixel to be resampled falls outside the ortho limits. This may happen when the ortho area is defined by a polygon.
Exclude Outside Limits Color?
If checked, valid image pixels that are the same color as the Outside Limits pixel color will be written with a slightly different color to ensure that no image pixels are the same color as the Outside Limits pixel color. This can be helpful when doing blending with VrMosaic.
Exclude Pure Black and Pure White pixels?
If checked, valid image pixels that are the pure black or pure white will be written with a slightly different color to ensure that no image pixels are viewed as background pixels during mosaic processing.
Default Output Prefix
This prefix will be added to the beginning of each default orthophoto output file name.
Default Output Postfix
This postfix will be added to the end of each default orthophoto output file name.
Default Output Directory
All ortho output files will be placed in this directory. If left blank, ortho output files will be placed in the project directory.
Use output pixel size for rounding values
If selected, the upper left corner of each ortho image will be aligned to an even interval of the output pixel size. This will ensure proper alignment when doing mosaicing.
Rounding value for ortho areas X (ground)
The lower left and upper right X value of each ortho area will be rounded to this value. Set this value to zero for no X rounding.
Rounding value for ortho areas Y (ground)
The lower left and upper right Y value of each ortho area will be rounded to this value. Set this value to zero for no Y rounding.
Delta X for World File coordinate (ground)
This value will be applied to the upper left corner X of the World File. The World File is generated when an orthophoto is created. Set this value to zero to leave the coordinate unchanged.
Delta Y for World File coordinate (ground)
This value will be applied to the upper left corner Y of the World File. The World File is generated when an orthophoto is created. Set this value to zero to leave the coordinate unchanged.
Ortho Area
The
output tab provides settings to define how the ortho areas are defined.
Z Source for Ortho Area Editor
If set to “DTM” a DTM surface will be computed for the image being used. This will result in a more accurate cursor location in the ortho area edit, but slower processing times when entering the editor.
If set to “Approx Z”, the current Approximate Z will be used when computing the cursor location. The editor will start quicker but the cursor location will be less accurate.
DTM Area for Ortho Area Editor
If set to “Full”, the DTM surface will be formed from the entire DTM extents. This does not affect the DTM surface used when creating the final output orthos. The DTM surface will not be recalculated for each image that is displayed in the ortho area editor.
If this to “Image Extents”, the DTM surface will be formed from the entities within the current image extents. The DTM surface will be recalculated for each image that is displayed in the ortho area editor.
Extents mode for default ortho area
· Image - Ortho areas will cover the entire image extents.
· Fiducials - Ortho area will be defined by the four corner fiducial positions.
· Centered - Ortho area will be centered around perspective center of photo and aligned to ground coordinate system.
Final ortho area extents will also be
affected by the values set below
If Image or Fiducials
mode is selected, the following options will be available:
Default ortho area left margin (pixels)
Determines how far right to move the left side of the default ortho area extents. This only affects ortho areas that are defined by default (not selected by the user).
Default ortho area right margin (pixels)
Determines how far right to move the right side of the default ortho area extents. This only affects ortho areas that are defined by default (not selected by the user).
Default ortho area top margin (pixels)
Determines how far right to move the top side of the default ortho area extents. This only affects ortho areas that are defined by default (not selected by the user).
Default ortho area bottom margin (pixels)
Determines how far right to move the bottom side of the default ortho area extents. This only affects ortho areas that are defined by default (not selected by the user).
If Centered mode is selected, the following
options will be available:
Default ortho area size along negative X axis (ground)
Determines how far to extend the ortho area along the negative X axis starting at the perspective photo center. This only affects ortho areas that are defined by default (not selected by the user).
A Default ortho area size along positive X axis (ground)
Determines how far to extend the ortho area along the positive X axis starting at the perspective photo center. This only affects ortho areas that are defined by default (not selected by the user).
Default ortho area size along negative Y axis (ground)
Determines how far to extend the ortho area along the negative Y axis starting at the perspective photo center. This only affects ortho areas that are defined by default (not selected by the user).
Default ortho area size along positive Y axis (ground)
Determines how far to extend the ortho area along the positive X axis starting at the perspective photo center. This only affects ortho areas that are defined by default (not selected by the user).
Contour Interval
Contour interval to be used when displaying contours in Ortho Area Editor.
Contour Index Interval
Contour index interval to be used when displaying contours in Ortho Area Editor. Index contours will be displayed in a different color than other contours.
Select VrOne display Files
Any VrOne files selected will be displayed on top of the images that are displayed in the Ortho Area editor. This can be useful if you have seam line defined and would like to see where they fall on the images.
VrOne display layer(s)
Defines the VrOne layers that contain entities to be plotted when editing ortho areas.
è Open Project
Display a dialog box that allows
an existing project file to be opened. If a project is already open it will be
closed before the new one is opened.
è Edit Project
A dialog box will be shown so
the project settings can be edited. See New Project command for details.
è Change Project
Location
This option is used to change
the project file locations when the project files are moved from one directory
or drive to another. A file open dialog will be displayed where an existing
VrOrtho project file can be selected. Once the file is selected the following
dialog is displayed.
Enter the new directory
locations for the items displayed and press the OK button. If the directory
locations were entered correctly, the project should now open without any
problems.
Orientation Menu
è Inner Orientation
Displays
the following dialog box that allows a single image to be selected for manual
inner orientation to be performed on images in the current project. All
of the project images will be available in the drop down box. A status for each
image will also be displayed.
After an image is selected,
the single image inner orientation application is displayed. Either the display
icons or standard VrOne zoom keys (PgUp, PgDn, Direction Arrows) can be used to find and measure
each fiducial. Single image inner orientation
displays three windows – The Status Window, the Overview Window, and the
Measurement Window
The Status Window
The Status Window displays the name of the image being measured, and a table of all fiducial measurements.
The row for the fiducial currently being measured will be highlighted. Clicking on any row in the table will make that fiducial current, and will cause the measurement window to zoom to that fiducial.
Edit Camera… - This will display a dialog box that allows the current camera definition to be edited.
Advance after measurement – If this is checked, then measuring a fiducial will cause the next highest fiducial number to become current. The measurement window will zoom to the next fiducial.
Clear Fiducial – This will set the x and y location for the currently highlighted fiducial to 0.0. This will remove the fiducial from the inner orientation process.
Clear Measurement – This will clear the measurement for the currently highlighted fiducial.
Total RMS Error – This displays the Total RMS Error based on the currently measured fiducials. This is updated real-time.
The Measurement Window
The Measurement window is where the fiducial measurements are taken. A fiducial is measured by placing the cross hairs over the center of the fiducial and clicking the left mouse button. If a fiducial has already been measured, a cross and a number will be displayed indicating the measurement location and the fiducial number that was measured.
The Overview Window
The Overview window shows the entire image along with fiducial number labels. You can move the square zoom cursor around in the overview window, and then press the left mouse button to make the measurement window zoom to the region beneath the cursor. The Page Up and Page Down keys can be used to change the size of the zoom window.
è Import VrTwo
Orientation
Displays the following dialog
box where vrtwo orientation can be imported. VrTwo
orientation files are saved as .orp files and are
saved using the model names defined in VrTwo orientation. Multiple .orp files may be imported at one time.
è Import
Exterior Orientations->ASOP - JFK
Displays the following dialog
box where exterior orientation can be imported from ASOP – JFK files.
è Import
Exterior Orientations->ORN - Aerosys
Displays the following dialog
box where exterior orientation can be imported from ORN - Aerosys
files.
è Import
Exterior Orientations->OPM -
Displays the following dialog box
where exterior orientation can be imported from OPM –
è Import
Exterior Orientations->PATB
Displays the following dialog
box where exterior orientation can be imported from PATB files.
è Set Ortho Area
Displays the following dialog
box that allows a single image to be selected for and displayed in the ortho
area editor. The ortho area editor is a tool for visually defining the area to
be extracted from an input image. When the ortho area editor is entered for the
first time for an image, the default area will be displayed based on the
project settings. If the ortho area is changed while in the editor, it will be
saved and used when the ortho is created. This provides a way to rectify small
or irregular shaped areas from images.
After an image is selected,
the following windows are displayed.
The top left dialog box
contains the main options for defining the current ortho area. The upper right
window is an overview of the entire image. The lower left window is the
measurement window. The overview and measurement windows have display icons
that cann be used to change the brightness and
contrast, and to zoom and pan the image. The standard VrOne zoom keys (PgUp, PgDn, Direction
Arrows) can also be used to zoom and pan the images.
Settings Window
Selection mode
Changes the selection mode. It is possible to define the area as a window or a polygon.
Start Output Selection
Selecting this button will allow the ortho to be defined. If Window selection mode is on, then the following menu keys dialog will be displayed.
Use the left mouse button to digitize the lower left corner of the desired ortho area. The prompt will change to display Dig upper right. Use the left mouse button to select the upper right of the ortho area. If you want the ortho area to align on an even grid, then select “0 To Grid Snap” or use F11 key to toggle grid snap mode on. The grid spacing can be controlled by selecting “4 Set Grid Res” or by pressing F4.
If Polygon selection mode is on, then the following menu keys dialog will be displayed.
Use the left mouse button to digitize points defining a polygon ortho area. You do not need to digitize a closing point. Press the right mouse button to finish the polygon collection. Use F3 to backup if a point is digitized by mistake. If you want the ortho area to align on an even grid, then select “0 To Grid Snap” or use F11 key to toggle grid snap mode on. The grid spacing can be controlled by selecting “4 Set Grid Res” or by pressing F4.
Zoom Output Area
This will zoom the measurement window to fit around the ortho area.
Set Area to DTM Bounds
Sets the output area to a polygon that follows along the boundary of the currently computed DTM surface.
Align Window to Ground
If window mode is selected, this will force the window to align to the ground coordinate system instead of the image edges. This will prevent images from containing corner pixels.
Lower Left X, Lower Left Y, Upper Right X, Upper Right Y
If “Align Window to Ground” is selected, you can enter the ground coordinates directly in these boxes instead of digitizing them in the measurement window.
Shade Output Area
If this is on, the interior of the ortho area will be “hatched” to make it stand out visually.
Show contours
If this is on, contours will be displayed based on the currently computed DTM surface. The contour intervals are controlled in the project settings.
Show control
If this is on and coordinate file is defined in the project, then the ground control points defined in the coordinate file will be displayed on the image.
Show other image borders
If this is on, then image borders will be displayed for all images in the project.
Show other image areas
If this is on, then ortho areas will be displayed for all images in the project. Only the active image area will be edited.
Show VrOne files
If this is on, then VrOne vector data will displayed on the image. The VrOne files and layers to display are defined in the project settings.
Output filename
If an output filename is entered here it will override the default output filename generated by the project settings. Leave this field empty to keep the default name.
Current Image
Displays the current image and allows a different image from the project to be selected. If a new image is selected the ortho area will load the new image.
Next Image
Press this button to switch to the next image in the project.
è Clear Inner
Orientations
Displays the following dialog
box where inner orientation on one or more images in the current project can be
cleared.
è Clear exterior
orientations
Displays the following dialog
box where exterior orientations on one or more images in the current project
can be cleared.
è Clear ortho
areas
Displays the following dialog
box where ortho areas on one or more images in the current project can be
cleared.
Create Menu
è Create Orthos
Displays
the following dialog box that allows multiple images to be selected for ortho
generation.
The current output name for each
image will displayed. Any images that do not already have an ortho image
created or have an ortho image created with a different pixel size than the
current setting will be selected automatically.
Select the input images that
you want to generate orthos for and then press OK to
begin the ortho generation process. The
following dialog box will display the output status.
