Bits of real estate: digitizing the church map collection of heritage maps at Auckland City Libraries.

Having been involved in digitizing heritage materials for a number of years it is clear there is no one 'right' way to carry out a digitization project. This is an explanation of how Auckland City Libraries has gone about digitizing a selection of maps in its collection.

First, to get rid of a misconception, the Church collection of maps is not a collection of maps of ecclesiastical properties, although it may look like some of them are. Many early real estate maps showed properties to be near churches and other amenities. In the case of the sale plan of Queens redoubt, it also shows that in the early 1860s, on the Great South Road, it was seen as an advantage to be near a military camp. (Figure 1)

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The Church maps are named after George Church who was a secondhand book dealer in Eden Terrace, Auckland and was one of the book dealers who sold to Sir George Grey.

The Auckland Public Library purchased material from George Church in 1916 for 60 pounds. This material consisted of photographs, manuscripts, books and maps. The map collection was kept as a separate entity while the rest of the material was accessioned into the general collections.

The collection consists of 566 maps, almost all to do with the sale of land, and some 200 of these maps were pasted into albums. The period most comprehensively covered is the 1860s to 1880s with a few into the early twentieth century. In general the maps are of the inner city of Auckland and the first ring of suburbs with a few further afield in the old Auckland Province. The plan of allotments for sale in Mount St. Mary's, Freemans Bay is typical of the collection. (Figure 2)

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By 2001 the library had already been carrying out a project to digitize large parts of the photograph collection and it was felt that the maps would add some 'colour' to the digital collections. Because of this commitment to digitization, time had already been spent on getting a digitization policy written. It was decided to digitize this collection of maps because of its significance for early Auckland and it would fulfil the criteria for the library's digitization projects--all items are out of copyright and the project would help with conservation and increase access to the material.

However, due to their different sizes the maps had been split into three main groups. About 200 of the smaller maps had been pasted into 5 scrapbooks, the smallest about 30 x 40 cm and the largest about 50 x 60cm. The smallest had been glued whole onto pages and in some cases not much could be done other than slicing the pages out of the scrapbook. Slightly larger maps had been glued onto the pages then folded so they fitted within the dimensions of the scrapbook. Digitization is often seen as a double-edged sword when it comes to conservation in that with increased visibility of material there is an increased demand to see that material. Previously, however, when a patron wanted to see a single map, the whole volume had to be brought out and in a lot of cases, the entire volume was looked through. Years of leafing through the volumes and unfolding and folding the maps had caused them to become very fragile and they needed to be disbound. The volumes of maps were sent to Wellington for the disbinding to be carried out by a conservator. After they were returned and had been digitized they were stored flat in acid-free folders between sheets of acid-free tissue and are now stored in flat cabinets. Since digitization, any items that need to be looked at have been brought out as single items. However, in all but a very few cases, the digital copy is sufficient, so in the long term digitization has decreased wear and tear on most of the maps.

The second group were slightly larger again so these had been pasted onto tusk cabinet hangers, where they stay until the glue dries out so much they easily come off. Putting them all in flat drawers would be the best solution but can't be achieved at the moment through a lack of space.

The last group, of which there are 35, are so large they are rolled and put into our rolled map storage. It was decided, in consultation with the photographers, to leave these and maybe digitize all 162 rolled maps at a later time as they will all need to be photographed in a specially set up studio, which increases the costs.

Before getting this far the library had to know there was money to pay for the project. A proposal had been put to the ASB bank whose objectives are to help organisations carrying out charitable, cultural, philanthropic and recreational work which is of benefit to the people of Auckland and Northland. Through the Auckland City Libraries Heritage Trust an application had been made to microfilm the New Zealand Woman's Weekly, the Sporting and Dramatic Review, and to conserve and digitize the Church map collection. The application was approved with an amount of $65,000 to be put aside for the maps.

After discussions with the photographers about the best way to copy each map, the cost for each came to $116, including GST. Once the money from the Heritage Trust was used up, funds from the photograph imaging project were used to digitize some additional maps that were not part of the Church collection. Now as the benefits of digitizing the collection are more easily seen, the Library has made available money through its imaging budget to get even more of the map collection copied.

In consultation with the photographers, it was agreed to photograph each map onto a 5x4 colour transparency, make a scan of the transparency, write two files for each map to a CD, and make a 5x7 colour file print.

So it was not the maps as such that were digitized, but the colour transparency. Auckland City Libraries went about it this way because the most detail could be captured by taking an analogue photograph of each map and then scanning these highly detailed positives on a drum scanner (a Howtek 7500). Digital cameras and flat bed scanners did not and still don't give as good detail as this method; also, most scanners are not large enough for most of the material. Therefore, the largest size that could be photographed in this way was about 135cm, anything larger will have to be photographed in parts, giving two or more transparencies, which when scanned can be knitted together to make one file. Again, this is how we decided to go about the process. Others may find their material is suited to being scanned in other ways, such as using the large scanner at the National Library.

However, another reason we used this method was because the maps could be placed in specially-made folders and transported not far across town to be photographed. Practical constraints such as these can be used to determine how a project is carried out.

The digital files produced are of two types. Both are put on the CD but it is the large TIFF file at around 100 to 110 megabytes that is used as an archival copy because it uses loss-less compression. This means when the file is compressed no information is lost, so there is no effect on the image quality. Because of the large size of the TIFF files, images from these are able to be blown up to their original size without any loss of detail and can even be reproduced considerably larger. Very good quality copies can also be made from the colour transparency to almost any size, for those who like their photographs made the old fashioned way.

The JPG file is created from the TIFF, but because this file type uses lossy compression it cannot be used as an archival copy. But at around 300K to 500K, they are a lot smaller and can be manipulated a lot easier for viewing over the Internet.

This brings me to the other main reason for digitizing material: to make it more accessible to researchers. This is easily achieved by having a file print made from each TIFF. But the most useful way of making things more accessible these days is by putting them on a database and ultimately on the Internet, through the library's web page. That way, the images can be made available both within the library as well as to people anywhere in the world who previously would not have had easy access to these collections.

The library has been involved in digitizing photographs since 2000 and has used DB/Textworks as the software for creating the database of photographs, Heritage Images Online. This software is also used for putting this database, and others created by Auckland City Libraries, on the web page. Therefore it was decided to use the same software for the maps. The metadata was entered into the database as soon as possible, which often meant transferring data directly from catalogue cards, and as every map to be digitized was handled, it was a good chance to update some of the information. Also, the catalogue for the maps in Special Collections was the only card catalogue still being used in the library, and because there is no retrospective cataloguing onto the library's catalogue, this was a good way of getting a digital copy of not only the maps but also the catalogue. When the CD comes back from the photographer, each JPG is saved at three different sizes by manipulating them using

PhotoShop software, and then saved on the council's server: first at its full size of about 500K, then through PhotoShop this was reduced to a medium size of around 50K, and finally this was reduced again to a thumbnail size of between 1 and 2K. Therefore each record has three files linked to it, and users are given the choice of whether they want to download the still quite large full-sized files.

A copy of the database was then made which only includes those records that have digital images attached. This database was then loaded on to the server and has been made accessible through the library's web site. This does mean we have been limited in our web delivery to what DB/Textworks can do. For instance, it doesn't have the ability to zoom in to images, but we have been able to provide the large, full-size images that people can navigate around.

There are other ways to deliver zoomable images over the internet, such as Zoomify (www.zoomify.com), which is free and links records to the JPG. This doesn't make the image any larger than the JPG as that is the file format it uses. Probably the best zoomable software is MrSID (www.lizardtech.com). However it is expensive, and to get the best results has to be linked to the TIFF file. This means the very large TIFF files would have to be loaded on to the server, creating issues around using up large amounts of memory.

As more items are digitized they will be added to this database, and the long-term aim is that the whole of the map catalogue will be accessible this way, both records with and without digital images.

Finally, the CDs are kept with the glass negatives in the photo storage at a constant temperature (18[degrees]C) and humidity (about 45 %) to slow down their decomposition. This doesn't stop them degrading, and Auckland City Libraries has recognised that in the medium term these digital copies will need to be migrated to new formats, as both software and hardware change, and as the CDs may perhaps become unusable.

By having both a colour transparency and a digital copy of the maps, the library can make copies of the maps (at different costs depending on the size, and the process used), or can sell a copy of the file for use in books and magazines. This has meant revenue gains for the library.

Not only that, but we have been able to send copies of material to other experts where it has been able to be identified. For example, the map of Wellington has been in the Auckland collection for many years, but we were able to send a digital copy of it to the Alexander Turnbull Library where it was identified by a researcher working on early town plans. The logic is that if researching Wellington, the best place to do it would be in Wellington. However, it has resulted in a significant heritage item being located in the Auckland collection. Perhaps there are many others waiting to be 'discovered'. (Figure 3)

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Therefore we have been able to fulfil the four criteria for digitization projects set out in the appendix to the Auckland City Libraries digitization policy: access, preservation, material is out of copyright, and there are revenue and efficiency gains.

With digitization, the technology will always be changing, so there will always be something better on the market. A decision has to be made at some point to commit to carrying out a project. Once this was done we found it best to use people who were experts in their field; that is librarians for providing the metadata, while outsourcing to photographers to carry out the photographic work and the library IT staff to make the database accessible through the web. That way, we have been able to make a nationally significant collection accessible to the whole country.

Maps Online can be found through the Auckland City Libraries web site at: http://www.aucklandcitylibraries.com/general. aspx?ct=322

Ian Snowdon

Auckland City Libraries

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