Scanning, Displaying and Printing Images

When you intend to scan an image, it is important to be clear about the purpose for which you are acquiring the image.
Once you know why you are scanning the image, you can "work back" to the appropriate settings.

Images are acquired for two main reasons:

(1) The image is to be displayed on a computer monitor (e.g. as part of a webpage).  

Factors to consider are: the size of the image in relation to the required size on screen, the display quality required and the kind of monitor you are displaying your image on. For more information go to Guidelines for displaying images on screen.

Factors to consider are: the size of the scanned image in relation to the printed image, the print quality required and the kind and of printer  you are using and the resolution it is capable of. For more information go to Guidelines for scanning when printing an image.

There are many different file formats in which images can be saved. The two main types are raster-based versus vector-based files.

Raster-based files involved a description of the colour and intensity of each possible dot of a given image whereas vector based files contain no information about specific dots, but are an assimilation of mathematically described objects.

Raster files are used for scanned images and are good for paint and photo-realistic images with complex patterns and textures. Vector files are good for predictable patterns such a lines, circles and squares and its main use is for text files and graphs.

Most image acquisition and manipulation software deals with raster based files. For more information about the different raster-based file formats their relative advantages and main uses, go to a brief or full description of image file types.  

Producing Effective Web Pages

There are a few important rules when making web pages. Go to rules for good web pages or read on for a summary of the main points.

1. You only have 15 seconds to grab the viewer's interest

2. Don't use more then 20KB of graphics on any page

3. Specify width and height on all images.

4. Reuse a small set of images throughout your site.

5. Don't make viewers resize of scroll.

6. Remember the page title

7. Don't click here

8. Use a spell checker

9. Always give the viewer some way to contact you.

10. Give visitors some reasons to make a return visit.

11. Be aware of different screen sizes and resolutions, taking account of toolbars and status bars.

Using the Leica DM RBE Research Microscope

The Leica DM RBE research microscope is able to operate as a conventional brightfield microscope, a polarising microscope, a phase contrast microscope, as a Nomarski contrast microscope and as a fluorescent microscope. These functions require different settings, such as changes of filters, prisms, polarisers, and beam splitters. For more information about the different functions, their use, and how to correctly configure and operate the microscope, visit the Leica DM RBE operating manual page.

Image Analysis Techniques

Images can be manipulated and analysed in several ways. One important procedure, often used to make the image ready for analysis, is image filtering. Several filtering procedures exist to eliminate background noise, erode or enhance object edges, or even extract channels and merge them into a second image. Image analysis includes several measurement techniques, such as counting, area measurement, perimeter measurement, determination of major and minor axes and many more. Several methods exist to extract information from shapes, such as analysing chain codes. Characteristics of the digital image, relevant to image analysis are described in The Digital Image and Image Analysis Techniques page. Alternatively you can go directly to the Image Analysis Techniques page for information on some of the often-used techniques available in image analysis programs such as Image Pro and NIH-Image.

For more information, contact:

Email iaaf@iaaf.uwa.edu.au

Tel: 6488 8649        Fax: 6488 1051