CSC/FAR 020, Computer Graphics, November 9, 2009 Dr. Dale E. Parson http://faculty.kutztown.edu/parson Outline for week 10, class 1 Exporting Files

PDF PDF is useful for exporting to word processing tools that cannot read Photoshop files. Download export.zip, Open Concert1.psd. Save as PDF without layers or Photoshop editing as Concert1.pdf. Save as PDF with layers and Photoshop editing as Concert1.pdf. Load into PowerPoint or Word (Insert -> Picture) and compare quality.

Output for Web GIF is an 8-bit format, good for up to 256 colors, retains transparency. JPEG uses 24-bit format with adjustable quality / file size trade-off, no transparency. Use JPEG for continuous-tone images. Limit image size to 800 x 600 pixels at 72 ppi for compatibility with browser screen area and resolution. Smaller file sizes load into browsers faster.

File -> Save for Web and Devices Allows preview of GIF and JPEG options. 2-Up and 4-Up tabs support comparisons. Dithering - Diffusion mixes fewer colors (smaller files) to simulate bigger gamut. Restrictive color reduction is standard web safe. Perceptual is biased towards perception. Selective biases towards colors in the image, compromise between the above two. Adaptive adjusts to the document, bigger files.

JPEG Quality parameters trade file size versus image fidelity. Increasing Blur can reduce noisy artifacts caused by JPEG compression. Matte substitutes for transparent areas. Use of either GIF and JPEG usually requires viewing in the context of a browser. Create / use thumbnails where possible to leave original image at higher resolution.

Inserting images into web pages. SeaMonkey is a free, open-source browser with HTML editing ability. It comes with an editor. http://www.seamonkey-project.org/ Adobe editor is Dreamweaver. Putting up a simple page to preview is straightforward. Embed an image with some text.