How to get your original images to us

We can accept scanned images in .tif or .jpg format or you can send us your original image by post and we will scan it for you. If you intend sending a scanned image please remember that the quality of the finished product is largely dependant on the quality of the scanned image.

For this type of work we prefer images in .tif format (see the 'techy' stuff at the bottom of the page for more details) and resolution of 200 dpi. Don’t worry, if we have a problem with your file we will email you with suggested alternative settings. If the image file is too large you will have problems in sending it by email as an attachment. If you have this problem contact us for instructions on how to upload directly to our server.

If you prefer us to carry out the scanning process then simply post the original photograph to us with your instructions. We would suggest you use next day guaranteed delivery as a minimum service to ensure that your photograph is delivered to us.

All you have to do is decide which photographs you want restored. Send them to us by either guaranteed next day delivery post or electronically as a .tif file attached to your email or use the Upload page. Wait for the results!

The 'techy' stuff

File formats

There are three popular file formats for digital images, .jpg (pronounced ‘jaypeg’), .gif (pronounced ‘giff’) and .tif (pronounced ‘tiff’). Each has its advantages and disadvantages, .gif and .tif files are referred to as ‘lossless’ indicating that no information is lost when we use them; .jpg is termed ‘lossy’ since some information is lost in the file compression process. This might lead us to believe that .jpg is a bad format but .jpg files are much smaller than .tif  and can handle more colours than .gif which makes them ideal for the internet.

.jpg This is the format of choice for photographic images which are to be distributed on the Internet. The files are compressed in such a way that the visual quality is maintained however much original information is discarded in the compression routines. Unfortunately this means that for restoration work the format is not ideal. We need as much original information as possible if we are to fill in the gaps produced by wear and tear on the original photograph.

.gif Gif is a lossless format but it is limited to 256 colours. Again this is adequate for screen use and for images with large areas of similar colour. On web pages things like buttons will often use the gif format. Gif also has the advantage of allowing you to specify a transparent colour which provides a means of producing images with transparent edges. For the majority of photographic manipulation however the limited colour range  means that the format is too restricted for practical use.

.tif Tif is also a lossless format and is able to work with 24k colours. This degree of colour definition comes at a price, the overall file size is huge in comparison to the other formats, however it is the format which retains the maximum amount of information from the original.

In short we must choose the most appropriate file format for the job in hand. For example at Digital History all photographs are scanned using the .tif file format before processing to give us the maximum information. The images on our web pages are all in .jpg format because we don’t want you to wait for hours for each page to load.

Scanning resolution

Having decided on the file format we must then chose the scanning resolution. The scanning resolution defines the number of individual dots captured by the scanner; this is normally measured in dpi (dots per inch). The higher the resolution the more dots captured and hence the more information available for image processing. There is no point in scanning more dots than you need, the file size becomes unmanageable, image processing software becomes slow and unstable, and the majority of the scanned information will be discarded by the computer before the image is printed.

There is no advantage in scanning more dots than exist on the original image, in fact there could be disadvantages because the scanning process produces unwanted patterns in the scanned image. The scanning resolution should be chosen to match the eventual output you require. If you are scanning for use on a web page then the output resolution will probably be 72 lpi (lines per inch). Since you are dealing with screen resolution the input scan can be the same as the output lpi, hence 72 dpi should be fine.

For printed material we use a general guide that the scanned image dpi should be between 1.5 and 2 times the output lpi. Magazines are usually printed at 133 lpi which would equate to a scanning resolution somewhere between 190 and 260 dpi.

There are always exceptions, if we need to blow up an area of the original to extract a single person from a group, then the original scanned image would need to be at a resolution high enough to provide sufficient information to print the extracted portion of the image at the size and lpi we need. For this type of work we may need to scan at up to 600 dpi but we would only scan the portion of the image we intended to use (not the whole photograph), otherwise the disadvantages of large files would come into play.

To sum up

Bigger is not always better but it often is! When dealing with scanned images you must think of the eventual output before making the decision about what scanning resolution to use. If the resolution is too small the output will look jagged, if the resolution is too high then the files created may be so large that your computer is simply unable to process the data presented to it. At Digital History we use a resolution of 200 dpi for normal images which are to be printed at the same size as the original. We use other resolutions when necessary for special editing such as enlargements.