There are relatively few public-domain, full-view books with pictures in GBS, but thumbnail view is valuable for them, to get a quick overview of the proportion and nature of the pictures, as shown in the example below.

On one level, more pictures in Google Books is gratifying — a theme of this blog! But the navigation/search capabilities for finding these pictures is limited. The best way seems to be to use Advanced Search and limit the search to Magazines. But the results listing for this is text-only. It would be much easier to search for pictures with the sort of thumbnail search results interface that’s used in Google Image Search.

In light of the launching of picture-laden magazines as part of Google Books, it’s interesting to note that only last month, Google launched Life magazine pictures, as part of Google Image Search. Google is facing the same choice that librarians have been considering for the last while — Should books (or magazines) that have many pictures be considered mainly as books that happen to have pictures, or as pictures that happen to be in books?

The pictures & links below are from magazines that are in Google Books. I’ve chosen them because I know from work on Hardin MD that they are on highly-searched subjects, which would likely appear in Google Image Search if they were crawlable.

Spider picture	Echinacea picture	Sickle cell anemia picture

.           .

Sickle cell anemia picture	Knee injuries picture

It’s widely acknowledged that the DjVu format excels in the online presentation of images/pictures, when compared with PDF, but this is not emphasized as much as it should be. In most discussions of eBooks, the emphasis is on text, and pictures are an afterthought.

This under-emphasis of commentators about the capability of DjVu in presenting books with pictures/images is perhaps related to the fact that the DjVu system itself has surprising design lapses that make it hard for the user to intuit the system’s graphic capabilities.

These powerful graphic features are especially related to use of thumbnails, which are much of what makes DjVu so useful for viewing books with pictures.

The thumbnail bar, shown to the left, is the key to navigating the pages of a book. The first hurdle in using this is that, oddly, the default display when a book is first displayed does not show the thumbnail bar. To turn it on, the user has to click the Show/hide thumbnail icon, which hides inconspicuously on the far right side of the toolbar. Turning on the thumbnail bar display can also be done by right clicking anywhere and choosing Layout – Thumbnails (In another odd, unaccountable oversight, the Show/hide thumbnail icon does not appear at all on the toolbar in the Macintosh -Safari version of DjVu, and the user has to use the right-click [or CTRL key] option to turn it on.)

The default display of the  thumbnail bar is quite small, so the next step in using it to get a better view of page contents is to enlarge the size of thumbnail images, by dragging the mouse, as shown at left.

The thumbnail bar works smoothly — Thumbnails are loaded rapidly as the user scrolls down to see more. Surprisingly the speed of loading seems to be little affected when the size of thumbnails is enlarged. It’s odd that the default size of images in the thumbnail bar is so small, when the larger size works so well — Another indication, I think, that the DjVu developers are not thinking much about use of the system for viewing books with pictures, since it’s so much easier to see details in pictures with larger thumbnails.

Finally, one more hurdle to using DjVu seems to exist in Internet Archive, which is the largest source of DjVu records — When the DjVu format is chosen in the “View the book” box, the link to open the DjVu file is broken. The way around this is to click All Files: HTTP, which is at the bottom of the “View the book” box. This goes to an index screen listing several formats, and clicking the one that ends in .djvu (usually the first in the list) successfully opens the file in DjVu format. I sent a question about this on Sept 8 to the DjVu.org forum, and have not gotten an answer on Sept 10 — Go here to see the question and to see if it has been answered.

Yogi Berra quote of the day: “You better cut the pizza in four pieces because I’m not hungry enough to eat six.”

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.

It’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]

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.

ICDL has many excellent features as a children’s book site e.g. its novel ways to find books, by color, theme, etc and its inclusion of books in a wealth of languages. The aspect of ICDL that I’ll highlight briefly here though, that can serve as a model for any site with illustrated books, is its polished delivery of text and pictures, featured especially in the Book Overview screen, shown below.

Book Overview: Calling the doves = El canto de las palomas

The Mouse-over Preview, that shows an enlarged version of a the thumbnail as the user holds the mouse pointer over it, makes this screen especially effective. To see the nice touches at work here, try changing the window size — As the window is made smaller, the thumbnails also become smaller, so that all of them remain visible. And, even better, the mouse-over preview window does NOT shrink, keeping the same size no matter how small the thumbnails become.

Though ICDL lacks some features of a full-fledged enterprise book-viewing system (text is not available as text), its innovative presentation of book pages serves to show how far existing systems have to go in presenting books with pictures — There’s just no substitute for displaying small versions of the book’s pages that show the pictures and how they relate to the text, and ICDL is a model of how to do this.

ICDL has its roots at the University of Maryland; it’s now run by the ICDL Foundation. It’s written in Java. For more technical details, see paper by ICDL authors.

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.

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.