Introduction to Digital Gravelometer
Digital Gravelometer is a tool for rapidly measuring the surface grain-size distribution of gravel. It has been designed for use on fluvial sediment, but should find application in other environments.
The software uses advanced image-processing techniques to identify and measure the size of grains in digital photographs. The procedure requires no user intervention except the identification of four control points in each image. The inputs to the software are photographs of sediment patches and the outputs are various statistics, parameters and graphs of the grain-size distributions. The software is able to analyse photographs individually, providing information about the grain-size distribution in each, or aggregate the information obtained from a group of images.
The software has three key benefits:
- Data collection and analysis are extremely quick, resulting in significant time and cost savings compared with conventional techniques;
- Measurements are made of small patches of sediment, avoiding the risk of integrating measurements across facies boundaries;
- Because the method is based on photographing the sediment, it does not result in damage to the surface being studied.
These benefits mean that the software is ideally suited to:
- Monitoring studies, where repeated sampling using conventional techniques would result in significant damage to the surface being studied;
- Analysis of grain-size variations at small spatial scales, such as on a single bar;
- Large-scale studies where the time and cost associated with conventional sampling techniques would result in fewer samples being collected than is desirable.
Before using the software for the first time, it is recommend that new users read the Get started section in this documentation.
Digital gravelometer has the following minimum system requirements:
|Processor||Pentium III or above|
|Operating system||Windows 2000 (with Service Pack 3 or 4) or Windows XP (with Service Pack 1 or 2)|
|Hard disk space||430 MB on the installation drive + 110 MB temporary storage for installation file|
|System memory (RAM)||256 MB (512 MB recommended)|
|Monitor/Display||256-colours, 800 x 600 resolution|
|Web browser||Any (a recent browser supporting cascading style sheets is recommended)|
This documentation is provided to help new users become familiar with Digital Gravelometer and as a reference source for experienced users.
Before using the software for the first time, it is recommend that new users read the Get started section. This provides an introduction to the operation of the software and a brief tutorial.
Instructions on how to obtain, install and activate the software (required after the free 21-day evaluation period) are contained in the Installation and activation section.
Useful guidance on the collection of images suitable for processing with Digital Gravelometer is provided in the Data collection section.
The Program operation section provides a thorough description of the operation of the software, taking the user step-by-step though the process of generating grain-size reports from digital photographs.
The Reference section provides a comprehensive reference source on the menus and dialogue boxes used to operate the program.
Digital Gravelometer uses a variety of image, data and dedicated file types. These are described in the File types section.
The Licence agreement section contains the terms of the various licences under which the software is distributed.
Technical information is provided to help advanced users get the best from Digital Gravelometer. This includes detailed descriptions of the various user-customizable parameters used by the software.
Finally, a list of Important references is provided as a resource for the user.
Various typographical conventions are used throughout the documentation to improve its clarity:
- Important definitions and concepts are indicated by emboldened and italicised text: project file.
- Software menu options are indicated by a gray background: .
- Buttons on dialogue boxes are emboldened: .
- Information to be typed by the user is shown in a mono-spaced font: sample_image_1.jpg.
Every effort has been made to ensure that Digital Gravelometer produces reliable grain-size information. However, the software is provided without warranty as detailed in the Licence Agreement.
Reliable results are most likely to be achieved if careful attention is paid to the recommended data collection procedures, in particular the lighting conditions and sampling area. The software provides the opportunity to visually assess the quality of the image segmentation achieved for each image during the grain measurement procedure. Intermediate steps towards grain measurement may be viewed on the screen and saved as image files. It is strongly recommended that users utilise these functions to satisfy themselves that the software is producing results of an appropriate quality for their application.