Image File Choices: MNHS

After understanding all kinds of the digital images, how do you think that librarians could benefit from them?  I am asked to use the Tiff type of images in the document delivery in Mills Music library. Obviously, librarians want to provide the best digital copies in the document delivery service. Can you think about the other services in the libraries that could use other types of images with smaller size? How do librarians choose between lossy and lossless types?

As Sarah pointed out in her lecture, it is usually about trading quality for file size.  Big files take up space and load slowly.  Keely Merchant gave a good description of how this works in her digital library/archive in her interview.  An original jpeg is submitted and saved, a large tiff is made and saved by the administrators for preservation purposes and a (probably smaller) jpeg is put up on the website for viewing.

Another reason to use a low-quality image is for a thumbnail.  When I have worked on my own websites in the past, I have used tiny, low-quality gifs for thumbnails that then link to larger jpegs when you click on them. The California Digital Libraries’ guidelines suggest gifs for thumbnails.  Very lossy small jpegs are also used.

Still another reason for keeping quality down might be to prevent people from using your library’s images in ways you don’t want them to.  The Minnesota Historical Society Library has a wonderful online collection including many beautiful historic photographs (http://greatriversnetwork.org/index.php?brand=cms).  Search results display listings along with very small (less than 10KB) jpeg thumbnails.  If you click a thumbnail you get to see a larger (about 50KB) jpeg that is big enough to enjoy the image but still very small in terms of reproducing a print copy for publication, or even enlarging to fill the span of a webpage. MNHS file sizes and types conform closely to the California Digital Libraries’ guidelines with the exception that these access image jpegs are actually considerably smaller (500 pixels measured on the long side instead of 800 pixels recommended by CDL)

Of course MNHS does not want you to publish these photos without paying for the rights. Perhaps their extra small access images are an effort to thwart unauthorized use?  I purchased the right to publish some photos from the MNHS collection for a CD booklet project and they sent me wonderfully huge tiff versions that I could zoom into a lot (some seemed to be endlessly deep when I got the big files, revealing details impossible to see in the jpeg).

(For example, look at this image (http://collections.mnhs.org/cms/largerimage.php?irn=10279199&catirn=10667064) and see if you can tell there is a second saloon further down the boardwalk called “Minnie Ha Ha Saloon,” or that there are two people relaxing in one of the boats and at least three people walking on the boardwalk!  All that is easy to see in the amazing tiff file.)

Advertisements

7 responses to “Image File Choices: MNHS

  1. Excellent post, Brian. One thing that is interesting to Keely’s situation, where she is soliciting materials taken by the public, is that she has no control over the materials she gets in terms of how they were created. In many cases, people may be snapping pictures and sending them to her in a lossy, compressed format such as a .jpeg, which she then turns around and artifically increases for archival purposes. There’s a lot of manipulation going on! Meanwhile, you’re absolutely right that people may maintain the high-resolution, uncompressed files and offer the lower-quality ones for free or for preview. You see this a lot with stock art companies.

    Thanks for the link to the Minnesota HS!

  2. Great point about using smaller sized images for copyright protection. As librarians we’re often worried about breaking copyright but we do have to protect it as well. Your example is a great way to have meaningful access but work within copyright limits. Guess it is another example of why file standards suggest having multiple copies of the same file in different formats.

    • Love the deer photo! Thanks for that. I don’t yet have a strong personal opinion about watermarks but I did notice that the California Digital Libraries guidelines we were looking at do advise against their use and instead proposes electronic watermarks or rights management administrative metadata:

      “The use of electronic watermarks (or “invisible” watermarks) is suggested as an alternative to visible watermarks. In general, other methods for attaching rights information to derivative access images (such as through rights management administrative metadata) is encouraged.”

      That does sound nicer than messing with the appearance of the image itself.

  3. I really like the idea of using a low-res image as a type of “teaser” for potentially increasing revenue for historical, library, government, etc societies. However, I wonder if there needs to be a certain amount of education of patrons/viewers on the potential benefits of using a high-resolution tiff file vs. a low-resolution jpg (for example). I did a report a few years ago on the historic streetcar system in the Twin Cities, MN, and had no real comprehension of the benefit I might get through purchasing the rights to download pictures/advertisements from the MN Historic Society. Such a shame, since the majority of my report was based on visual images of the ephemera of the time!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s