Introduction

This article describes experiences in image manipulation by students of the Digital Image Management program as well as provide some tips for similar projects. The School of Library and Information Science at the University of North Texas received a grant in 1998 from the Institute of Library and Museums Services to create a new program for Certificate of Advanced Studies in Digital Image Management. The goal of the program is to prepare professionals for work in the digital imaging environment. The one-year program includes classes (24 credit hours) and lab work. Each student has to work two hours per week in the digital lab along with their studies. All necessary equipment is provided. This hands-on project uses the Sepia photographic collection from the African-American Museum in Dallas as an initial start. Students scan photographs, create and design database forms, enter descriptive data taken from the information on the photographs and folders in which those photographs were separated by museum curators, purchase hardware and software, and do research on various topics.

Currently, SLIS provides students also with opportunities to receive a Masters degree in Digital Libraries, a Certificate of Advanced Studies in Digital Image Management and financially supports the doctoral students whose research concentrate on imaging. Current ILMS fellows are deeply involved in research. Some of the graduates with the CAS in Digital Imaging Management remain at the university for further work in the doctoral program. Using their previous experience, students continue to face new problems and to work on their research topics (e.g. image metadata, collaboration problems, resolution studies)

Image acquisition

Before the actual work with the museum collections beginning students are required to be familiar with major software used in the lab: Microsoft Office package, Macromedia Dreamweaver 3, Fireworks 3, and Adobe Photoshop 5.5.

In addition to their studies and lab hours, IMLS Fellows attend of Adobe PhotoShop workshops that later help them to work with acquired images. They learn about different image file formats, basic image manipulation techniques, image optimization for the WWW, some valuable layers’ techniques, and vector graphics. Students are also introduced to Adobe ImageReady and Adobe Illustrator software.

There are approximately 50 thousand items in the Sepia collection of the African American Museum in Dallas. About ten thousand black and white photographs are currently in digital format. Five digit numbers are adequate for the Identification Number (ID) following the first three letters of the collection name. Writing the ID number on the back of the photo with a pencil (previously it was agreed with a curator of the museum), students can easily track what is the last scanned photograph. There is a bulletin board in the digital lab showing who is the last person working with the collection, how many images are scanned, what is the last scanned photograph ID, what has been done with the images: scanned and saved in TIFF, converted to JPEG, cleaned JPEG, written to the database.

Each image (black and white photo) is scanned in TIFF format with 400 dpi resolution in Grayscale mode for archival purposes.

• Why 400dpi? The main issues regarding storage space and time for image representation have been discussed during classes, lab hours and fellows’ meetings. Without official scanning standards the decision for use of 400dpi is dependant upon available equipment and human resources.
• Why grayscale? To maintain all shades of the image it's better to scan in grayscale. In Grayscale mode pixels are black and white, and have up to 255 shades of gray. While scanning black and white photos in “grayscale” mode and “true color” mode in the digital lab, students have a choice to select between those two modes.

A regular photograph 8x10inches scanned as a True Color mode TIFF is about 30-40Mb and in Grayscale mode about 8-12 Mb. There is a huge difference between the two files considering storage issues, but the quality of the scanned photos is almost the same.

Here is an example from the Sepia collection, folder “Ruth Brown.”

The scanning of each photograph 8”x10” in TIFF format takes about 1 minute, smaller photographs take less time. While scanning photographs 5x7 inches or smaller students place a couple of photos on the scanner glass to be pre-scanned. Every saved file is assigned a unique identification number according to a standard created by IMLS Fellows (e.g. Sep00346).

Due to vast variety of JPEG format types and incompatibility of software tools some software displays the message “Unrecognized JPEG format” while opening the file. Images also require additional work in Adobe Photoshop 5.5: rotating, cropping, reducing size for web to fit computer screen, and sometimes sharpening. A decision is made to scan in TIFF format only and then to convert TIFF files to JPEG using Adobe Photoshop 5.5.

Almost all photographs have a white canvas around the original photo. While scanning the students select the size of the actual photo and if possible save it without the surrounding white space. An average scanned canvas can take up to 2.2 MB in addition to the image file. Eliminating the canvas frame can save a lot of space while burning the CDs.

All image manipulations are based upon the procedures set up by the class including the converting procedure. Using Adobe Photoshop 5.5 students convert TIFF images to JPEGS. The problem is that it is impossible to automate “BATCH” images converting directly from the server where reside. It takes a considerable amount of time to copy all TIFF images from the server and also slows down an overall network bandwidth. Using Adobe Photoshop 5.5 for converting TIFF images to JPEG students need to change image mode. After scanning a photograph, all TIFF images are in Indexed Color mode. TIFF images cannot be converted to JPEG format until they have been changed to Grayscale mode in Adobe Photoshop 5.5 program.

• Approximately 70 MB per minute can be saved by automated “BATCH” conversion of TIFFs to JPEGs. An average file size ranges from 9 to 12MB. We think that if images are smaller than that it would take less time for Adobe Photoshop 5.5 to read TIFF format and the process of conversion would be faster.
• It takes about 2 minutes to rotate and to crop JPEG images of 100Mb with recorded “Actions” in Adobe Photoshop 5.5.

After image manipulation, non-rewrittable CDs are used to store the Sepia image archive. This type of the CDs is bought in an effort to cut down on costs. There was no reason to use re-writtable CDs for archival purposes. The amount of images that can be burned on a CD depends upon image file sizes. A problem may encountered while burning 620MB simply because the software is not able to finish the burning process. However 600MB can be burned without any problems. About 25Mb on each CD is left for further indexing projects.

• To move 600MB of images to the hard disk takes approximately 5 minutes on the Pentium II 400MHz PC. Time also greatly depends upon the network connection speed. We could not estimate the exact time of copying images from a server to a hard disk because the network traffic varies all the time.
• Burning a CD with 600MB using Easy CD software takes about 20 minutes.

Conclusion

All ten IMLS fellows from six countries are more than satisfied with the provided program curriculum. This new method of teaching and learning that combines theoretical classes with real work projects helps students better understand real world problems, get them ready to face problems, teaches them to compromise and to work as a team.

One of the things that has impressed fellows for Digital Imaging Management the most has been the experience with the technology and software used for digital image management. IMLS fellows definitely need to spend more time working with the programs mentioned above to become more experienced users. It is a privilege to have a digital lab where students can spend as much time as they want scanning photographs, entering data into the database, and experimenting with available software. The Digital Imaging Management Program gives all IMLS fellows an opportunity to visit professional conferences within the USA and overseas. These conferences provide colleagues with information about what should be done in digitization activities throughout the world and help to establish an international research agenda.

The funding received from the U.S. federal Institute of Museum and Library Services supports the fellowships and equipment. The contributions of the project partners make it possible to keep the IMLS fellows engaged and learning.

To read full report of IMLS fellows during the first year of studies you can ask for a free CD-ROM Revelations in Digital Image Management and Learning Strategies digilab@unt.edu or visit http://digitallab.lis.unt.edu/research