Image Data

Introduction to Images

The general perception will be that images are photos, however, while all photos are images, not all images are photos. Images are a convenient way to display things on a screen and in this wiki, that convenience is used in a number of different ways. It is anticipated that there will ultimately be many photos on this wiki to support the stories written, but images are also used to make up things like the Trails that display at the top right of each station page, allowing you to move quickly to 'next' and 'previous' sections and stations. Station pages are now also getting access to engineers drawings of the station yards which will help researchers understand how some of these yards expanded and shrunk over the years, these are all held as image files. There will also be a number of other uses of images to aid the researcher.

Any image you want to display in the wiki needs to be uploaded to the wiki first. This is a straightforward process using the 'Upload file' utility which you can find in the menu to the left of the screen. Note that this is called upload file, not upload image, as you can also upload some other file types.

There is a 32MB limit to the size of a file that can be uploaded, but there is a 12.5 Mega Pixels limit on image files. Above that and thumbnails of the image are unable to be created for display. 12.5Mp relates to the absolute size of the file, not a compressed file size, so 4Mp wide x 3Mp high would be acceptable as would 12Mp x 1Mp, but not 6Mp x 3Mp.

It is worth mentioning here too that this wiki is not intended to be a repository for high-quality images, so while reducing an image down to a size that meets the above requirements, it also meets the wiki objective of presenting an adequate image, as well as providing additional information as to where a higher resolution image may be able to be sourced from.

Heritage Images

There are two aspects to heritage images from the Wiki perspective, the first is images held in this wiki, and the second and more significant is references to images that have been published. Each of these are important but quite different and it is only recently that a structured way of storing and accessing heritage images on the wiki has been developed. This is in direct response to various interest groups sharing heritage photos on the likes of Facebook, where there is no structure at all. To try and find an image that you know has been viewed there before can be nigh impossible. The original focus of this wiki was to create a means of indexing references to published images, with a preliminary process developed, but there is still a lot of work to do in that area.

Stored Heritage Images

I have developed a process for managing images to be saved (uploaded) to the wiki. The uploading of an image file is very easy, the challenge is to know what the image has been named. For this reason I have opted for a random name (i.e. a number) and rely on a database entry to record details about the image in a structured way. While this is still early days, the database table and data entry forms have been created and are able to be used. The system used to auto generate the image number needs to be rethought due to the lag between creating the record, and the database being updated. This usually means the user is ready to process a second image when the database does not know that the previous image is loaded yet, so an incorrect number is generated. There will be a tidy solution for this I have not discovered yet.

All images stored or used by the wiki are all stored in the File 'namespace'. In order to be able to separate Heritage images from all other sorts of images e.g. book covers and icons used in the wiki etc., Heritage Images are also grouped in their own 'category'. This allows them to be searched easily . Every wiki page has a Photo Gallery tab at the top. The aim is to be able to write a query that will enable the display of heritage photos relevant to that particular page. The photo gallery tab on this page would then provide access to all the heritage photos.

Published Images

A further aim of this wiki is to create an index to images that have appeared in publications (books, magazines, newspapers etc). This will be a significant body of work and will need to grow over quite a number of years. It should allow rapid searching for images at various railway locations and of various railway things and people.

To be really useful the index will need to record things that are visible in an image but not necessarily the main subject. This also has the proviso that a copy of the image would not likely be held in the wiki, you just need a reference to which publication(s) it has appeared in. The initial structures within the wiki to achieve all that have been worked out and test data is being prepared. One complication is matching up images when one is a cropped portion of another. No doubt things will be worked out to cove these eventualities, particularly when it might be years after individual entries were made that two two images are in fact identified as being from the same original.