Digitome Corporation Volumetric Analysis Application Software
Program Digitome3: Analysis Page Theory of Operation
31-July-2009
Any unauthorized disclosure, duplication, or use is a violation of civil and criminal law.
This product is owned by Digitome Corporation with all rights reserved.
Portions of the software herein described are protected under US Patents
5051904, 5070454, 5319550, 6671349, 6898266, and 6917668.
Also under US Provisional Applications
60/418,743; 60/422,532; 60/425,808; and 60/432,217.
Also under Japanese Patent JP02042347.
© Copyright 1998-2009 - All Rights Reserved - Digitome Corporation
Digitome is a registered trademark of Digitome Corporation
Contents
Introduction ........................................................................................................................................... 1
Analysis Page ....................................................................................................................................... 2
Caption Bar ........................................................................................................................................... 2
The Tabs ............................................................................................................................................... 3
The Page .............................................................................................................................................. 3
Section a. Adjust Image .................................................................................................................... 3
Image Absorption Coefficient Slider ............................................................................................... 3
Image Gamma Slider ..................................................................................................................... 3
Image Resolution Slider ................................................................................................................. 4
Image Zoom Factor Slider ............................................................................................................. 4
Section b. Volumetric Display ............................................................................................................ 5
Volumetric Controls ....................................................................................................................... 5
Record and Playback Controls .................................................................................................... 10
Section c. Adjust View ..................................................................................................................... 10
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Program Digitome3: Analysis Page Theory of Operation
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Introduction
A Theory of Operation is a description of how a device or system should work. Its
purpose is to give the user a mental model so that he will be better able to apply the
device or system to specific problems. Such a mental model can assist the diagnosis of
apparent and/or actual faulty behavior. A Theory of Operation is not intended to give the
reader a full and detailed description of the internal structure and functionality of the
device or system sufficient for its replication.
The Digitome Corporation Volumetric Analysis Software consists of four programs.
Program
Digitome3
Digitome4
Digitome5
Digitome6
Description
Single Source Geometry Volumetric Analysis
Multiple Source Geometry Volumetric Analysis
Geometric Magnification Geometry Volumetric Analysis
Multiple Position Geometry Volumetric Analysis
The four programs have a tabbed user interface with each tab implementing a major
program task. The tabs are identified as follows:
Tab Label
Configuration
Intensity
Radiography
Reference
Calibration
Acquisition
Analysis
Task description
Input of the source, fixture, and calibration parameters
Image acquisition and testing of image detector pixel intensity calibration
Image acquisition, enhancement, and inspection of 2D x-ray exams
Image acquisition and calibration of image detector reference position
Image acquisition and calibration of source or turntable position and orientation
Image acquisition of image set for volumetric analysis
Computation, presentation, and inspection of volumetric x-ray exam
One opens a tab to expose the associated user interface functionality by placing the
mouse cursor over the tab and left clicking. The resulting display is to be referred to as a
page by the same name as the tab label (ie. Analysis page).
The various pages are substantially similar across the four programs except for the
variations necessitated by the differences in geometry. The differences are associated
primarily with image acquisition and geometry calibration issues. The remaining
functionality is the same across all four programs.
This document is focused on the Theory of Operation of the Radiography page of
program Digitome3. Most of the information presented is directly applicable to the same
page in the other three Volumetric Analysis programs: Digitome4, Digitome5, and
Digitome6.
Note: The software has been tested and runs on fully updated Windows 2000, Windows
XP, and Windows 7 RC1. The software has not been exhaustively tested on Windows
Vista so its correct operation is uncertain.
Note: Digitome Corporation application software and documentation is protected by US
Copyright law and portions are protected by various US and international Patents
elsewhere disclosed.
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Program Digitome3: Analysis Page Theory of Operation
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Analysis Page
The radiography page appears as follows (limited to XGA (1024x786) on Microsoft
Windows 7 RC1.
Note: The page will not look like this until an exam is loaded (see below).
Caption Bar
The caption bar has the normal windows behavior except for the text displayed. It shows
the standard name of the executing program but it is followed by a program description
and a Memory Load percent. The number displayed will be an estimate of the used
percentage of physical memory available to the program. This number will change
depending upon the details of the program operation.
The Memory Load percent has an alarmed limit of 90%. This alarmed limit can be
reached if too many other programs are loaded and running at the same time. In which
case simply terminate one or more of the other running programs.
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The Memory Load limit can also eventually be reached if the program itself has a
memory leak. A memory leak, if left to accumulate long enough, can cause the program
to malfunction or crash. Normally, the percent load will bounce around but will not grow
without limit. If it does, your workaround is to terminate and restart the program. Please
inform Digitome Corporation if this behavior is observed as it represents a previously
undetected malfunction of the software or operating system.
The Tabs
The tabs are as specified in the introduction. The Analysis tab is in front with the other
tabs to the back. This front and back relationship shows which page is being displayed at
the moment.
To the extreme right, there is a button labeled “Help”. Left click on this button to display
the User Reference Manual.
The Page
There are three sections to the page: “a. Adjust Image”, “b. Volumetric Display”, and “c.
Adjust View”.
Section a. Adjust Image
Section “a” adjusts the parameters controlling the Section b view image qualities.
Image Absorption Coefficient Slider
The Absorption Coefficient controls the combination function of the image set images.
The combination function simulates the effect of light passing through a stack of films.
The Absorption Coefficient controls the equivalent average exposure of each film. Higher
Absorption values simulate more exposed images while lower value simulates less
exposed images. A value of one, simulates a “normal” Digitome® exposure level.
Left clicking on the Reset button will reset Absorption, Gamma, Resolution, and Zoom
sliders to their default values.
Image Gamma Slider
There is the original image corrected image set that has been loaded. There is a
selected area computed Digitome® Volumetric View image. All of these images have
sixteen bit pixels for a potential dynamic range of 0 to 65535. The actual portion of the
potential dynamic range used is the dynamic range of the original image set which may
be less than the full sixteen bit range.
There is the image being displayed in the display window. The display hardware is a
thirty two bit pixel true color display. That pixel consists of four eight bit bytes (0 to 255)
representing the level of Red, Green, Blue, and Alpha. Alpha is the level of transparency
with 0 being opaque and 255 being transparent.
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The x-ray images are gray scale images. A true color grey scale image will have Red,
Green, and Blue levels all the same with an Alpha of zero. This means that a grey scale
image for display will have eight bit pixels with a dynamic range of 0 to 255. This is
further complicated by Windows specific internals in that its limited to a dynamic range of
0 to 235. The remaining levels being reserved for system colors. This is an artifact of
history due to the limitation of hardware fifteen to twenty years ago. There is little visible
effect cause by this but the internals are made somewhat more complicated.
There is a major complication provided by the disparity of pixel size and dynamic range
between the image from the x-ray detector and the display. This is accommodated by a
standard photometric function called Gamma. It is essentially an exponential transfer
function that translates from a higher dynamic range to a lower one. A gamma of one is
a linear translation. Greater than one has the effect of increasing contrast by
exponentially compressing the brighter portions more than the darker portions. Less than
one has the effect of decreasing contrast by doing the reverse.
Left clicking on the Reset button will reset the Absorption, Gamma, Resolution, and Zoom
sliders to their default values.
Image Resolution Slider
The image resolution slider controls the apparent resolution of the volumetric view being
displayed. The setting determines the distance between pixels being computed. If the
distance is greater than the resolution of the x-ray image detector, the computed pixel is
replicated to fill the apparent pixel. When the resolution slider is set to higher values, the
image takes on a distinct pixilation appearance. Since fewer pixels are computed, the
speed of computation is much increased.
The Auto Res check box controls the automatic switching between some arbitrary higher
setting of the resolution slider and its default setting at the bottom. When selected and
when one of the Adjust View sliders is moved, the resolution slider is moved to its higher
value and the views will be computed at the lower resolution. Then, after a short time of
not moving an Adjust View slider, the Resolution slider will reset to the bottom and a full
resolution volumetric view will be computed and displayed.
This capability facilitates searching the object volume for “interesting” features at a much
faster rate than would be possible at full resolution. Then, when the feature is thought to
be found, it will be presented at full resolution without further operator action.
Left clicking on the Reset button will reset the Absorption, Gamma, Resolution, and Zoom
sliders to their default values.
Image Zoom Factor Slider
Typically, the images acquired are much larger than the display window. Hence when
the full image is displayed, it is de magnified to a significant extent. The Zoom Slider
controls the magnification of the image. At magnifications larger than the default
magnification, only the portion of the image centered on the center of the default image
will be displayed. The portion of the image to be centered can be changed simply by
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moving the curser (which changes to a +) to the desired image centering point. Then,
when you increase the Zoom factor, that new center will be used.
Left clicking on the Reset button will reset Absorption, Gamma, Resolution, and Zoom
sliders to their default values.
Section b. Volumetric Display
Section “b” supports the volumetric viewing of a Digitome® x-ray image set.
The label following the “Image:”, at the approximate top center of the image display
window, is the name of the loaded image set.
There are two rows of controls at the bottom of the display window. The top row supports
volumetric analysis. The bottom row supports the recording and playback of computed
views.
Volumetric Controls
Load Exam Button activates the Select Exam Dialog for Single Source Image Sets
Select the desired exam. Left click on OK to load the selected image set. A left click on
Cancel will cancel the dialog. A left click on Edit, will activate the Edit Image Set Settings
Dialog for the selected image set (see below). A left click on Rename will activate the
Image Set Name dialog for the selected image set. A left click on Delete will delete the
selected image set. Caution: the deleted image set is not recoverable.
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Edit Exam Button activates the Edit Image Settings Dialog for the loaded exam.
Only the first page of the dialog has editable items. The remaining pages are for
inspection only.
Editable Items
Description
Object Height
Object Magnification
Radius of Result
Gamma Correction
Absorption
View Level
Rotation Adjustment
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Description
Brief description of the exam
The distance between the high point of the object and the turntable
Magnification factor to be applied to the exam view
The radius from the turntable center that includes features of interest
Default Gamma Correction value
Default image combination absorption coefficient
View level height above the turntable
Default exam view rotation in degrees
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Measure View activates the Measure View Tool
Notice section “d” to the right of the image display. Line indicates the length of the
measure line (red line on screen). Size indicates the size of the feature as measured on
the intensity profile at the bottom of the page.
The drawing of the line is initiated by left clicking on the Locate button. Then move the
cursor to the display window. The cursor will change from and arrow to a plus. Move
the cursor to one side of a feature to be measured. Left click and drag so that the line
extends through the feature of interest. Then release the left mouse button.
Next left click on the Profile button. An intensity profile of the line will appear at the
bottom of the page. The intensity is plotted in dark cyan and the differential of the profile
is plotted in light cyan. Move the cursor to one peak of the differential and left click.
Move the cursor to another peak and observe the size. That will be the distance between
the two selected positions on the profile.
Left click on the Clear button to clear the Measurement tool.
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Viewer activates the select saved and recorded image folder dialog.
The Save Directory folder contains the views saved by left clicking on the Save button in
the Adjust View section (see below).
The Album.[name] folders contain the views generated and save by the Auto Scan
function (see below).
The Recording.[name] folders contain the views generated and saved by the Record and
Playback function (see blow).
Left click on Display will display a thumbnail view of the views in the folder, an enlarged
view of a selected thumbnail and the settings under which the view was generated, and
the deletion of a selected view. The enlarged view will have a limited set of image
processing and measurement tools available for use.
Left clicking on the Cancel button will cancel the operation.
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To view the contents of the selected folder, left click on the OK button. The Album and
Recoding Viewer will be displayed.
Button Description
Settings
Displays the settings under which the presented view was generated
Save As
Saves the presented view to a user selected location and name
Delete
Deletes the presented view
Print
Prints the presented view along with its settings
Next
Advances to the next image in the saved or recorded sequence
Previous
Regresses to the previous image in the saved or recorded sequence
Scan
Scans the saved or recorded sequence
Stop
Stops a scan in process
The vertical red bars indicate the settings of the sliders under which the view was
generated.
A typical settings display:
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Record and Playback Controls
The Record/Playback radio button control selects the record/playback mode for the Start
button.
Left click on the Start button starts the Record/Playback session.
If the Record mode is selected, a view and its settings will be saved in memory for each
change in the settings of the Adjust Image and Adjust View sliders. This capability is also
driven by the Auto Scan capability and the optional 3D Mouse (see below).
If the Playback mode is selected, a previously recorded set will be played back on the
page with the sliders indicating the settings under which the view as generated. The
interval between views will be determined by the interval between views as recorded.
Left click on the Stop button will stop the Record/Playback session.
Left click on the Compile button will generate and save the previously recorded sequence
of views and associated settings in a user selected Album Recording Folder.
Left click on the Export button will export the selected compiled recording to a user
selected folder.
Section c. Adjust View
Slider
Rotation
Tilt
Level
Travel
Description
Rotation of the view plane about an axis perpendicular to the the turntable
Tilt of the view plane about the horizontal center axis of the view plane
Distance of the center of the view plane above the turntable
Perpendicular displacement of the view plane
Button
Save
Reset
3D Mouse
Album
Description
Saves the current image in the Save folder
Resets the sliders to their default positions
Enables dialog to set sensitivity of the optional 3D Mouse (see below)
Enables an album for auto scan
Auto scan is the automatic scanning of Travel from a negative position to an equal
positive position with the view being computed and save at one pixel intervals along with
the settings specification. They are saved in the selected Album folder.
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3D Mouse
An optional 3D Mouse is interfaced to these four sliders. See: SpaceNavigator by
3DConnexion.
A SpaceNavigator is a six degree of freedom mouse: x, y, z, roll, pitch, and yaw.
Position so the cable exits from the rear. The x axis is left to right, the y axis is up and
down, the z axes is front to back. Roll is a twist about the y axis, pitch is a twist about the
x axis, and yaw is a twist about the y axis. The Rotation slider is connected to yaw. The
Tilt slider is connected to pitch. The Level slider is connected to the y axis. The Travel
slider is connected to the z axis. The other two axes are unused.
The device also has two buttons. The left button resets the sliders. The right button nulls
the device to eliminate drift.
The device plugs into a USB port and is automatically detected by the software and
operating system. There is no need to load a driver.
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