Detailed Contents
1. Introduction
2. Starting DigImage
3. Basic Operation
4. Sample Session
5. Command Files
6. Movies
7. Coordinate Systems
8. Warnings, Errors and Crashes
9. Utilities
10. Macros
11. Other Considerations
12. Updates
Appendix A: Menus
Index
Unlike other image processing systems, DigImage has been developed specifically for analysing fluid flows in the laboratory. It has been under continual development since 1989 and has been extensively used in a wide range of projects. DigImage offers a menu driven, user friendly interface combined with an extensive context sensitive help system. This combination allows ready access to the system and facilitates exploratory analysis. In addition a powerful command file structure and authoring facility allows ready automation of frequently used analyses.
DigImage includes many standard image processing techniques such as filtering, contouring and image enhancement, in addition to a range of more specific capabilities such as particle tracking. A fundamental feature of fluid dynamics experimental analysis is that the time dimension is of crucial importance, yet the complexity of the analysis renders it impossible to perform the necessary computations in real time. DigImage exercises the precise control of a video tape recorder required to accurately reconstruct the time series. In addition to the built-in facilities, the DigImage development system allows the user to develop specific algorithms in Fortran and integrate them fully into DigImage. This is possible through the exhaustive range of library routines supplied to provide the user interface, control the frame grabber and video tape recorder, and the low and medium levels of processing images.
The purpose of this document is to provide a general introduction and overview of DigImage from the user's perspective. More precise details of DigImage operation are available through the context sensitive help system (see below).
Within this document we shall
observe the following notation conventions:
| Notation | Description |
| <key> | Angular brackets indicate a single key press. If the key must be modified by <shift>, <ctrl> or <alt>, then the key stroke is written as <shift><key> etc. |
| [F Feature] | Menu options are indicated by square brackets, including the key required to access the option. If the option is itself a further menu, then a colon (:) is included after the access key (e.g. [S: Submenu]). These access keys are relative to the current location. |
| [RO Option] | The access key sequence, relative to the current menu. This may include passage through any intermediate menus. Only the entry key of the intermediate menus is given. |
| [;MA Absolute] | If a leading semicolon (;) is included, then the access sequence an absolute reference from the main (root) menu. The use of the colon is similar to the backslash (\) in MS-DOS. Note that <;> may be used from menus or command files to rapidly return to the main menu. |
| [qR Relative] | If a leading lower case q (for quit) is included, then the access sequence is from the current menu's parent (i.e. it will quit from your current menu first). The q may be repeated. |
| Place at Top, Bottom or Nowhere ?
{TBN}-> | Characters enclosed in braces indicate that one of the enclosed characters should be pressed to select a chosen option. Each character corresponds to the option in the preceding text which includes that capitalised character. For example, pressing <T> will select the "Top" option. This mechanism is a short-hand way of setting up a menu of the form:
T Top B Bottom N NowherePressing <return> will use the default option, which is always the first in the list. If a mouse is installed, clicking the left button will select the default option. If a binary choice is required (e.g. {YN} or {WS}) then <space> or clicking the right button will select the second option. Note that <space> (or the right button) has no effect when more than two options are presented. |
| C:\..> | This is used to indicate commands entered to the MS-DOS prompt. |
| %DIGIMAGE% | This is the path on which DigImage is installed. The % symbols on either side indicate that it is a MS-DOS environment variable. |
| Which buffer ? | Shading, without a border, is used to indicate text produced by DigImage. |
| -> | Single character command required by DigImage- <return> is NOT needed. |
| => | User input required by DigImage followed by <return>. If a mouse is installed, clicking the left button is equivalent to pressing <return>. |
| [option] | The item enclosed by the [ ] pair is optional. Typically this is used to describe an option to a command entered at the MS-DOS prompt or in a command file command. |
Screen output | Grey background (or indicated colour for HTML) is used to indicate computer output while running DigImage. |
# Start menu C: Contours | Shadowed outline (or indicated colour for HTML) is used to indicate the contents of a command file. |
| Key | Description |
| <f1> | Help on current activity |
| <shift><f1> | General help |
| <ctrl><f1> | Function key template (from menus only) |
| <alt><f1> | Index on all DigImage options (like the index found in a text book) |
<shift><f1> gives general help on basic keyboard and command file operation. Like <f1>, <shift><f1> may be pressed at any time when user input is required, except when the -> or => is in reverse video. Press either <Q> or <escape> to exit <shift><f1> Help. After using help, the screen is returned to it's original state - nothing is affected.
Interactive short cuts to a number of DigImage's facilities are provided by certain function key sequences. The purpose of <ctrl><f1> is to simply a simple template of the function keys giving a brief reminder of which key performs which operation. As with most of the function keys it describes, this template may be accessed only from a menu.
The index system, accessed either by <alt><f1> or [;I Index of facilities], enables a particular feature to be located within DigImage, without actually knowing which menu it appears under. Within the index the user may scroll up or down, or jump to the first letter of the index word. If desired, the user may select an item from the index and either jump to the help associated with that item, jump to the menu containing that item, or execute the item concerned.
| Form/File | Document Name | Topic |
| HlpFiles\*.HLP | Context-sensitive help files | All aspects of DigImage. File names correspond to menu position. A trailing underscore indicates a menu level help file. Utility help files indicated by @file_name. For example, help for [;GG Grab single buffer] is found in HlpFiles\GG.HLP, and help for [;C: Contours] is in HlpFiles\C_.HLP. |
| Hard copy (A4),
Document\OverView.PS, Document\OverView\index.htm Document\OverView.pdf | Installation Guide | Covers the installation and updating of the DigImage executable system. |
| Hardcopy (A4),
Document\Track2D.PS, Document\Track2D\index.htm, Document\Track2D.pdf | Two Dimensional Particle Tracking | Overview of the particle tracking system within DigImage. |
| Hardcopy (A4),
Document\DigiPlot.PS, Document\DigiPlot\index.htm, Document\DigiPlot.pdf | DigiPlot Users Guide | Introduction to the DigiPlot plotting utility |
| Hard copy (A4),
Document\DigiFile.PS Document\DigiFile\index.htm, Document\DigiFile.pdf | DigiFile Users Guide | Introduction to the DigiFile file conversion and printing utility. |
| Hard copy (A4),
Document\QuickRef.PS & Document\QuickRef.htm, Document\QuickRef.pdf | Quick Reference | Quick reference cards for DigImage and DigiPlot. |
| Hard copy (A4),
Document\Update.TXT | Changes in Updated | Outlines any changes or enhancements made to DigImage since the last version was released. |
| Document\WhatIs.TXT | Components of DigImage Executable System | Lists the main files present in the DigImage Executable System. |
| Hard copy (A4) & Document\Develop.TXT | DigImage Development | Outlines how to develop additional modules and link them into DigImage. |
| Hard copy (A4) & Document\Trk2Code.TXT | Trk2DVel Development | Outlines the additional considerations for programs in the Trk2DVel system. |
| Document\Changes.TXT | Changes to Development System | Gives details of any changes since the last release affecting programs written under the Development System. |
| Document\Autoexec.TXT | AutoExec.BAT | Sample AutoExec.BAT file for MS-DOS and Windows 3.1. |
| Document\Autoex95.TXT | AutoExec.BAT | Sample AutoExec.BAT file for Windows 95. |
| Document\Config95.TXT | Config.SYS | Sample CONFIG.SYS file for Windows 95. |
| Hard copy (A4) & Document\Names.LST | List of Routine Names | Contains a list of the subroutine and function names available in the DigImage Development System. |
| Hard copy (A4) & Document\Entry.LST | List of Routine Entry Points | Contains details of the subroutine and function entry points. |
| Hard copy (A4) & Document\Internal.LST | List of Internal Routines | Contains a list of the internal DigImage routines and functions. These names should not be used for user written routines. |
| Document\Cameras.TXT | Review of video cameras | Brief notes and evaluations of various video cameras. |
| Document\Videos.TXT | Review of Video Recorders | Brief notes and evaluations of various video recorders. |
| Document\AG7330.TXT | Communications protocol for Panasonic AG7330 | List of commands and questions understood by the AG7330 VTR. |
| Document\AG7350.TXT | Communications protocol for Panasonic AG7350 | List of commands and questions understood by the AG7350 VTR. |
As indicated above, some of the documentation is available in
hypertext markup language (html). These documents are extensively
linked and indexed using hypertext and may be viewed using any
normal web browser. The most up to date versions of this documentation
is available over the world wide web under http://www.damtp.cam.ac.uk/user/fdl/people/sd103/digimage/document/index.htm .
DigImage documentation page
DigImage home page
Stuart Dalziel's home page