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APPENDIX 3C—IMAGE PREPARATION

American

  • Software Used: Graphic Converter
  • Images Created: All images were reduced to 72 dpi with maximum size constraints of 640 x 400 pixels and saved in compressed JPEG format using medium image quality settings. In addition a 50x50 pixel version was created for each image to serve as a thumbnail.

Columbia

  • Software Used: Kodak PhotoCD Access Plus to do the batch extraction of PhotoCd images and Paint Shop and some UNIX tools to do the batch image conversions
  • Images Created: 1) 100 x 70 thumbnail (GIF89), 2) 350 x 250 pixel JPEG, 3) 700 x 500 pixel JPEG, and 4) 1200 x 900 pixel JPEG; all JPEGS were compressed at 50% quality.

Cornell

  • Software Used: Adobe Photoshop
  • Images Created: Three versions of each image: 1) JPEG thumbnails (longer side 120 pixels), 2) medium-resolution JPEG (longer side 390), and3) high-resolution TIFF or JPEG images.

Illinois

  • Software Used: Lview Pro, Hijaak95, and Adobe Photoshop
  • Images Created: 1) full-size JPEG, 2) medium-size JPEG, 400 pixels tall, and 3) thumbnail JPEG, 125 tall. Full and medium images were converted to JPEG using the highest quality compression possible, whereas thumbnail images were compressed at slightly lower-quality settings.

Maryland

  • Software Used: Alchemy and Lview
  • Images Created: Two versions: 1) thumbnail size (longer side 150 pixels) 2) "standard" size (longer side 700 pixels). All the images were converted to Windows bitmap (BMP) files to work with their custom software programs, Caprina™ and Searchslide™. During Year 1 a subset of the images was converted to GIF and stored on the Web server so that they could be accessed by a course that was using the Macintosh platform, which resulted in duplicates. In order to solve this issue, they purchased a library that allowed them to display GIF images from Visual Basic. In Year 2, all the images were converted from BMP to GIF and they were able to provide access to the Novell server and the images through the Web server.

Michigan

  • Software Used: Equilibrium Debabelizer, Adobe Photoshop, and Image Magick
  • Images Created: 4 image sizes: 1) GIF89A (interlaced) thumbnail: (longer side 90 pixels), 2) JFIF (JPEG) or GIF (longer side 320 pixels) 3) JFIF (JPEG) or GIF (longer side 640 pixels), 4) JFIF (JPEG) or GIF (longer side 960 pixels), 5) full-size JFIF (JPEG), or GIF as provided by the museums (except Eastman where BASE *4 resolution was used). Compression levels: for GIF images, loseless LZW compression was used and for JFIF images lossy JPEG with a quality of 80 was used. When the maximum resolution provided was less than standard or medium or large sizes, those sizes were generated. In some cases the maximum size was comparable to the small size, then only the thumbnail derivatives were generated.

Virginia

  • Software Used: Image Magick and Debabelizer
  • Images Created: 1) standard thumbnail JPEG, 2) screen-size image JPEG. JPEGs made with Image Magick were compressed at a quality setting of 85 and the JPEGs made with Debabelizer were compressed at a quality setting of 75.

Back to Chapter 3

 


The Cost of Digital Image Distribution:
The Social and Economic Implications of
the Production, Distribution, and Usage of Image Data

By Howard Besser & Robert Yamashita
http://sunsite.berkeley.edu/Imaging/Databases/1998mellon