Finding a heavily illustrated book that’s in both Google Books (GBS) and Internet Archive (IA) gives a good comparison of the strengths and weaknesses in the way illustrated books are presented in these systems.

Shown below are the “intro” pages for the book in the 2 systems. The clear advantage of the GBS intro page is that the sample thumbnails in the lower right make it immediately obvious that the book has COLOR pictures of good quality.

In Internet Archive the main job of intro screen (below) is to direct the user to options to view the book, in the box in the upper left, and there’s no indication that the book contains pictures.

Even after pulling up the DjVu option to view the book — which is a tricky matter, see how to do it here — there’s no intro screen at all in DjVu, just an imposing blank page waiting for the user to change display options or begin paging through the book sequentially.

DjVuIt’s when the user chooses display options and begins viewing the book that the advantages of DjVu become evident. The most important option, especially if pictures are an important part of the book, as they are in the Mracek Atlas book shown here, is to turn on the thumbnail display bar (at left) by clicking the icon in the lower right corner of the DjVu display window. It then becomes easy to scroll through the thumbnails and get a good view of the nature of the pictures in the book, and how they relate to the text. In the Mracek Atlas, it happens that the first third of the book is all text, and the last two-thirds is mostly pictures, so the user can scroll to the pictures easily.

Use of thumbnails is a good way to provide access to pictures in a book. But as simple and obvious as it is, thumbnail access is lacking in most e-book systems, so both GBS and DjVu are to be applauded for providing it, in their different ways. Here’s a comparison of the two systems …

In GBS, the About this book page gives immediate thumbnail access to a maximum of 30 pictures. Additional pictures have no thumbnail access, and can only be found by scrolling through pages or text searching.

DjVu has the disadvantage of having no Intro page that gives an overview of pictures in the book. But when the user knows how to set the display options, it provides good thumbnail access to an unlimited number of pictures. In a book like he Mracek Atlas, with over 100 pictures, this is a definite advantage.

Postscript: It wasn’t easy to find a book that’s in both GBS and IA, so I was especially pleased to find the Mracek Atlas discussed here that has pictures in Hardin MD! The full citation for the book is: Atlas of diseases of the skin, by Franz Mracek, 1899 [GBS | IA]

Flickr takes the sun out of the sunset“Flickr takes the sun out of the sunset” — The picture to the left from Flickr shows the full picture and its square thumbnail, in the inset. Thumbnails like these are generated automatically by Flickr and other photo management systems. They work by taking a portion from the center to make the thumbnail. This works well if the center has the most important subject in the picture. But if the picture is relatively wide or tall, and its main subject is not in the center, as in the example at left, with the sun being to one side, the thumbnail misses it. Looking at this example (Long Beach Sunset) in Flickr, note that the first thumbnail on the Flickr page (top left) is the one for the larger picture (that’s shown on our page with the thumbnail in yellow-outlined inset).

In large mass-production systems like Flickr, automatic thumbnails are unavoidable, and my point is not that they should never be used. Instead, my point is that, on many levels, pictures require more human input than text to make them optimally usable. Pattern recognition — the simple observation that the thumbnail of a picture of a sunset SHOULD CONTAIN THE SUN — is something that the human brain does easily, but this does not come naturally for a computer.


Another sort of problem in automatic production of thumbnails is making a thumbnail by simply reducing the size of the large picture. If the main subject of the picture is relatively small, it is not visible in a small thumbnail.

The picture to the left is from the Hardin Library ContentDM collection. The inset in the upper right shows the thumbnail that’s generated automatically by the system, which does a poor job of showing details of the picture. The lower inset shows a thumbnail made manually, which gives a much more clear view of the central image in the picture.

Cropping of a picture to produce a thumbnail, as done here, takes more subtle human judgement than the case with the Flickr picture in the first example, where the weakness of automatic production is obvious. With cropping, there’s inevitably a trade-off between showing the whole picture in the thumbnail or showing the most important subject of the picture. In cases such as this one from ContentDM, where most all of the detail in the picture will be lost in a small thumbnail, it seems better to focus on a central image that will show up in the thumbnail.

Finally, a few examples from Hardin MD, below, show how we have done cropping to improve the detail in our thumbnails. The thumbnails on the left in each of the three pairs are made by simply reducing the size of the full picture. On the right in each pair are the thumbnails we use, that we have made by cropping the full picture before making the thumbnail.

The biomedical, scientific pictures that we work with in Hardin MD are fairly easy to make thumbnails for, because they generally have a well-defined focus, that’s usually captured well by automatically-generated thumbnails. More artistic, humanities-oriented pictures, such as the ones discussed here from Flickr and ContentDM, however, often have more subtle subjects, that benefit from the human intelligent touch in the production of thumbnails.

Over the last three years, we have added close to 800 pictures on about 100 diseases/conditions to Hardin MD.

As the volume of pictures has grown, providing access to them becomes more difficult. For some time, we have grouped pictures on specific disease conditions into small galleries, each with about 3-12 pictures (ant bites, athletes foot, atopic dermatitis below). Recently, however, we have expanded the gallery format, broadening it into larger gallery collections, which have links to the smaller galleries.

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Use of the gallery format has been very effective in increasing access to our pictures — We are finding that users are much more likely to click thumbnail disease links deeper on the page than when a list of text links is provided.

In addition to the gallery collection pages for AIDS, cancer, and child diseases, which are shown on the gallery gateway page above, there are also gallery collections for foot problems, herpes, insect bites, mouth sores, nail problems, oral diseases, skin rashes, STD’s, and tropical diseases, all of which are linked on the inclusive gallery page.

[When Hardin MD was launched in 1996, its main purpose was to provide links to health science resources on the Web. In recent years, the emphasis has been on providing access to medical pictures.]

We first started tracking how well Google was finding Hardin MD pages in about 2001, when search engine optimization was in its infancy, and most people, like us, had not heard the term “SEO.” But in today’s lingo, that’s pretty much what we were doing — Learning to use language that would help people searching in Google to find our pages — So here’s a little example of using search engine optimization techniques before they became famous as SEO. …

Users of Hardin MD will notice that the word “pictures” is used frequently on our pages and the word “images” is rarely used. Why is this? Basically, the answer is simple — We use “pictures” because that’s the word people use in searching.

The screen-shots below, for the Hardin MD : Impetigo Pictures page, show this clearly. The Extreme Tracker shot for this page shows the large proportion of search engine traffic from the word “pictures” (36%) compared to the small amount of traffic from the word “images” (0.6%).

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Hardin MD : Impetigo Pictures page
Keywords (Extreme Tracker)

The Google screen-shots show that the Impetigo Pictures page gets an equally high ranking for the two words, so it’s apparent that “pictures” is being searched much more frequently.

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Google search: impetigo pictures
Google search: impetigo images

(Note that these screen-shots have been photo-edited to fit the space — Ads and other text not relevant to the article have been removed. All screen-shots captured in July 2008.)

Here’s the background …

In about 2001, we started noticing how people were finding Hardin MD pages in search engines, and designing our pages to make them more likely to be found. An important part of this was using words that people were more likely to search (e.g. “heart diseases” instead of “cardiology”). Tools such as WordTracker that show how many people are searching for particular words are especially useful for this.

About this same time, we were starting to make links to other sites that have pictures on medical/disease subjects. Using WordTracker, and ExtremeTracker (to see words people were searching to find our pages) it was striking that the word “pictures” was very effective. At the time, we assumed that the appropriate word to use was “images,” since that word is what’s used on most medical/disease pages at other sites. We could see clearly, however, that using the word “pictures” on our pages brought much more traffic than the word “images.” So we’ve gone on from there, and now have high rankings in Google for many medical/disease subjects combined with “pictures,” as with Impetigo.

Extreme Tracker | WordTracker

As computers have become more powerful, many of the aspects of handling text that were formerly done by humans have been taken over by computers. Pictures, however, are much more difficult to automate — Recognizing patterns remains a task that humans do much better than computers. A human infant can easily tell the difference between a cat and a dog, but it’s difficult to train a computer to do this.

In pre-Google days, the task of finding good lists of web links needed the input of smart humans (and Hardin MD was on the cutting edge in doing this). Now, though, Google Web Search gives us all the lists we need.

Pictures are another story — on many levels, pictures require much more human input than text.

The basic, intractable problem with finding pictures is that they have no innate “handle” allowing them to be found. Text serves as its own handle, so it’s easy for Google Web Search to find it. But Google Image Search has a much more difficult task. It still has to rely on some sort of text handle that’s associated with a picture to find it, and is at loss to find pictures not associated with text.

The explosive growth of Hardin MD since 2001 (page views in 2008 are over 50 times larger) has been strongly correlated with the addition of pictures. This time period has also gone along with the growing presence of Google, with its page-rank technology, and this has come to make old-style list-keeping, as had been featured in Hardin MD, less important.

Though Google has accomplished much in the retrieval of text-based pages, it’s made little progress in making pictures more accessible. Google Image Search is the second most-used Google service, but its basic approach has changed little over the years.

The basic problem for image search is that pictures don’t have a natural handle to search for. Because of this it takes much more computer power for the Google spider to find new pictures, and consequently it takes much longer for them to be spidered, compared to text pages (measured in months instead of days).

Beyond the problem of identifying pictures there are other difficult-to-automate problems for image search:
• How to display search results most efficiently to help the user find the what they want — Do you rank results according to picture size, number of related pictures at a site, or some other, more subjective measure of quality?
• What’s the best way to display thumbnail images in search results?
• How much weight should be given to pictures that have associated text that helps interpret the picture?

So — Good news for picture people! — I would suggest that pictures are a growth sector of the information industry, and a human-intensive one. I would predict that text-based librarians will continue to be replaced, as computers become more prominent. But there will continue to be a need for human intelligence working in all areas relating to pictures, from indexing/tagging to designing systems to make them more accessible.