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An Introduction to Digital Images

Guidelines No. 3.1         Issue 1.2         June 2007


The remarkable improvements in computers and digital imaging software in recent years makes it an ideal time for local historians to tap the benefits of the "new technology" as far as images are concerned.

The aim of these guidelines is to assist absolute beginners to get started with digital imaging and to suggest some projects well suited to local historians. In addition it gives a very brief review of suitable software packages and web sites which provide tutorials and general advice.


1. Introduction
2. Absolute Basics (Beginners Only!)
3. Digital Imaging Software
4. Useful Web Sites for Tutorials and Advice
5. Suggested Digital Image Projects for Local Historians
6. Concluding Remarks

1.    Introduction          [top]

The importance of photographs old and new in local history is undisputed.  However, conventional photographic techniques are both time consuming and expensive.  If you own a computer then it is a very short step to enter the world of digital images with their advantages of infinite life and negligible costs to copy and distribute.  That is of course a grossly simplified picture and as with most activities it takes time and effort to get really proficient in the subject.  However, it can be extremely rewarding right from the start but the question is how do you start? Some very basic information on digital images is contained in Section 2 which is marked (Beginners Only!).  Section 3 looks at a few of the commercial and freeware packages available for digital images. Some of these programs are completely free of charge (apart from the cost of downloading them from the Internet) while commercial packages can cost several hundred pounds.  Section 4 gives links to a few of the excellent tutorial sites on the web which cater for all levels of expertise. Section 5 suggests some practical applications.

2.    Absolute Basics (Beginners Only!)           [top]

Digital images are analogous to a patchwork quilt made up of tiny squares of material of different colours.  Taken together the eye merges all the squares into a single composite image, in short a picture.  In one common method of storing digital images the amounts of red green and blue that make up the colour of each square are stored in a computer file as numbers.  These numbers can then be used to produce pictures by a printer or on the computer screen. It really is "painting by numbers"! The great advantage of this system is that special computer software can be used to adjust the size and colour of each of the little squares which are called "pixels" from the phrase "picture elements".  These adjustments can be used to correct faults in ordinary photographs and create special effects in any image.  Of course it is not quite as easy as that sounds but with practice starting with simple examples good results can be obtained from the outset and very soon you should be able to deal with real projects. It should be made clear that digital images does not necessarily imply the use of a digital camera.  Certainly they are a very convenient means of producing digital images but the cheaper cameras do not yet produce results that match digital images which originate from standard 35mm photography.  For many people it is probably best to start with their existing camera and get their negatives or slides scanned into digital format at a photographers before going to the outlay of a good digital camera. The great advantages of digital images are that theoretically they will never degrade and they can be copied and distributed at negligible cost compared to conventional photographs.  An introduction to matters such as scanners, digital cameras, printers, has been given in earlier guidelines in this series (No. 1 and No. 2).

Once you have acquired your digital imaging software (see below) you will be able to get to grips with editing images. First start the program and create a new (blank) image following the instructions for your software as given in the manual. You will most likely find you have a "toolbar" displayed which contains a number of small pictures call icons. (The "toolbar" might not be visible by default in which case consult the manual to see how to make it visible). Each icon represents a "tool" which becomes available to use when you click on it. Typically some of the tools allow you draw lines, circles, curves, polygons or simply draw freehand shapes. You will be able to change the line width and colour to suit your needs. Other tools allow you to erase portions of the image or fill with colour selected regions. You can zoom in and zoom out to suit the job in hand. Lettering is applied using the text tool. There will be facilities to copy or move elements of your image to another part of it. It will be possible to resize images, change the resolution and even rotate the whole image.

Having gained some experience with a "blank canvas" you can try loading up a copy of some image that you might find in a samples folder installed with your software. Alternatively just look for any file on your hard disk with the file extension .JPG or .TIF or .GIF and use the same tools to try modifying it. It is always best to work on a copy of an image as when you save a modified image you may find it has overwritten the original image which will then be lost. With full colour or black and white photographs (called greyscale images) you can alter the brightness and contrast to suit.

Once you have got started it really is a case of experimenting and getting more experience. The manual for your software should explain the tools you have and how they are used while your library and the Internet are of course excellent sources of further information.

3.    Digital Imaging Software           [top]

In 2007 the professional's choice remains Adobe PhotoShop (currently Version CS at about £480) which has held the top spot for many years now. It has a vast array of facilities for creating all the special effects we see every day in advertisements and magazines. In recent years Adobe have released a heavily cut-down so-called "light edition" at about £50 but often bundled free with quality scanning equipment. This is extremely powerful software fully capable of handling all the standard editing functions. The latest in this series is PhotoShop Elements (now Version 5) at a similar price but with extra features. The other main contender in the £50 to £100 market is Paint Shop Pro (now version XI at about £90). Other useful products are CorelDraw    MGI Photosuite   and  Ulead PhotoImpact.

As ever there is a host of software available to download for free from the Internet. One that is particularly good for viewing images is IrfanView. This creates slideshows (images shown for a preset time and then a different image displayed). It provides rudimentary image editing facilities and changes can be applied to a large batch of images. All in all this program is well worth downloading. Searching the Internet can be done with any of the Search Engines but Google at is undoubtedly one of the best due to the way it displays the most relevant results high in the listings.

A good place to look for freeware (and shareware - where you pay a licence fee to the author only if you continue to use the software after a free trial) is at

Complete earlier versions of some of the main packages can sometimes be found on the 'free' cover disks on computing magazines. These versions may be a year or so out of date but they could provide all that you want and so the £3 to £5 cover price represents excellent value.

As with most things it is probably a good idea to ask around and find out what other people use. [I mainly use Adobe PhotoShop PhotoShop Elements Version 2 (2002) which was 'bundled' with a scanner I bought].

Specialist software for displaying large images at a very high resolution over the Internet is now becoming generally available. The MrSID format is well suited for applications such as maps and photographs. Details are available in Guidelines No 5 or from the LizardTech web site.

4.    Useful Web Sites for Tutorials and Advice           [top]

As in the previous section Google is a recommended search engine to seek out tutorials on the web. What is available is constantly changing and so it is a good idea to try keywords in the Google search box such as

         Tutorial digital imaging


         FAQ digital imaging

The following currently offer a wide range of useful advice ( January 2002). Most sites have fairly good navigation facilities and so it is easy to 'dip into' a particular topic at each site. This can be useful for some of the trickier topics where it can be very helpful read up the topic on different sites. Everybody has their own way of putting over the same information and some approaches are likely to suit you more than others.

General Advice

Web Resource list Digital Imaging and Media Technology Initiative of the Library of the University of Illinois at Urbana-Champaign (large collection of useful links).

Paint Shop Pro Learning Centre. There are a large number of tutorials from basic through to advanced. There is some bias towards Paint Shop Pro but still contains useful information.

Digital Imaging Tutorial Cornell University Library, Department of Preservation and Conservation. Good introduction

Graphics Software Support site. The site has quite a lot of topical information.


Wayne Fulton's Scantips Useful clear tutorials.


Visual Arts Data Service (VADS) Creating Digital Resources for the Visual Arts Standards and Good Practice. The AHDS is a national service which helps the academic community create, deposit, preserve or discover and use digital collections in the arts and humanities.

Technical Advisory Service for Images (TASI) .UK Advisory Service for Higher Education . Aim is to "Advise and support the academic community on the digital creation, storage and delivery of image-related information".

California Digital Library Digital Image Format Standards July 9, 2001 Reviewed and updated annually. Format Standards for professional applications.

5.    Suggested Digital Image Projects for Local Historians          [top]

A series of "Then" and "Now" pictures of your area. The camera position for the "Now" picture is made to match as closely as possible the existing "Then" shot.

A compilation of "old" pictures with extended captions published on CD This could be either to create an archive or possibly for sale to the community.

The creation of a photographic archive of your Community at the present time. An example of this type of project is the Gloucestershire 2000 Photographic Archive . The aim is to record the people, the activities and the buildings at the beginning of the 21st Century.

The production of digital versions of old Maps and other documents relating to the Community. Improved technologies such as the Adobe Acrobat PDF software are now making such projects much more feasible in recent years.

The preservation of existing collections of slides and prints by converting them to digital images. The Gloucestershire Society for Industrial Archaeology has several collections, some dating back to the 1960s and 1970s, which are awaiting conversion.

Processing of photographic prints, slides, negatives and documents to provide illustrations in publications and displays.

Guidelines No 7 in this series contains detailed advice about file formats, scanning resolution and file sizes for some of these applications.

6.    Concluding Remarks           [top]

These guidelines cover a range of topics from an introduction for absolute beginners to suitable software, advice from the Internet and finally suggestions for Local History projects. It should be noted that these notes are very much a first attempt and it is freely acknowledged that they are capable of improvement. Thus feedback will be very much welcomed. Please send your comments to the Author at or the Chairman.           [top]