WHOI Silhouette DIGITIZER

This software and documentation were developed by Woods Hole Oceanographic Inst. and were funded as part of

The National Science Foundation
GLOBEC program

WHOI Silhouette DIGITIZER is a MATLAB-based computer program for measuring the lengths of marine organisms in the macrozooplankton size range. DIGITIZER begins by displaying a scanned photographic image of a seawater slurry containing large numbers of marine organisms, upon which is superimposed a reference grid. DIGITIZER then allows you to measure the organisms' lengths using the cursor on the computer screen. DIGITIZER automatically calculates each organism’s biomass and generates spreadsheet-compatible output listings of basic statistics derived from the data. DIGITIZER also produces text files of lengths, weights, and size-frequency histograms.

The User's Guide is available on your browser or can be downloaded and viewed in MS Word.

Here's how to install DIGITIZER.

A different set of files is required depending on your operating system and the version of MATLAB you are using.

STEP 1: Copy ONE of the zipped program folders to your hard disk. The choice depends on which version of Windows and which version of MATLAB you are using.

version 1.1:

For Windows XP and MATLAB 7.5, copy zipped folder dig110_XP_mat75 to hard disk.

Note: This version is not totally debugged but does run successfully. One minor issue that has not been resolved is that the window in which the image file is selected opens UNDER the previous window so it appears that the program has stalled. Just move the top window to find the active window.

version 1.0:

For Windows 2000 or XP and MATLAB 6.5, copy zipped folder dig100w2000m65 to hard disk.

For Windows 2000 or XP and MATLAB 6.1, copy zipped folder dig100w2000m61 to hard disk.

For Windows 98 and MATLAB 6.5, copy zipped folder dig100w98m65 to hard disk.

For Windows 98 and MATLAB 6.1, copy zipped folder dig100w98m61 to hard disk.

STEP 2: Change the name of the resulting hard disk folder to dig100 or dig1.1.

STEP 3: Copy the tutorial zipped folder tut100 to hard disk.

STEP 4: IMPORTANT: Change the disk access properties of both folders and all the files in them to READ/WRITE access, by un-checking their "Read-only" Attributes. Here's how to do this:

In My Computer or Windows Explorer, select the file(s) or folder(s) whose disk access property(s) you want to change.
(You can select multiple files or folders by using the shift key in the customary Windows manner: click on the first file in the contiguous list of files or folders to be selected; then hold down the shift key and click on the last file in the contiguous list of files or folders to be selected.)
On the File menu, click Properties.
(You can also right-click a folder or file on your desktop, and then click Properties.)
Un-check the "Read-only" checkbox in the Properties dialog box and click OK.

The tutorials assume that you have copied the folders to hard drive D.

You can change the folder names if you wish, but don't change any file names.

IMPORTANT: Please note that the default.men and default.wgt files must be located in the 'working directory' along with the image file in order for DIGITIZER to run.

Note: In version dig1.1, a subdirectory with special menu (defaultso2.men) and weight (defaultso.wgt) files for Southern Ocean krill is included. The length-to-weight regression formula differs for Antarctic krill (mainly Euphausia superba) from most other species. Use these two files instead of the default files if you are analyzing zooplankton from the Southern Ocean.