1 / 14

Working with Image Files

Working with Image Files. Aaron Fuegi aarondf@bu.edu. Working with Image Files - Topics. Image Files Compression, Resolution, Formats, etc... Applications Batch processing Working with image sets or sequences Movies MPEG, DVD Publications Resolution Color space. Image Files.

nadine
Download Presentation

Working with Image Files

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Working with Image Files Aaron Fuegi aarondf@bu.edu IS&T Scientific Visualization Tutorial – Spring 2010

  2. Working with Image Files - Topics IS&T Scientific Visualization Tutorial – Spring 2010 • Image Files • Compression, Resolution, Formats, etc... • Applications • Batch processing • Working with image sets or sequences • Movies • MPEG, DVD • Publications • Resolution • Color space

  3. Image Files • PPM Image File – 24 bit color, 3 pixels by 3 pixels IS&T Scientific Visualization Tutorial – Spring 2010 P3 3 3 255 0 0 0 128 0 0 255 0 0 128 128 128 0 128 0 0 255 0 255 255 255 0 0 128 0 0 255

  4. Image Files - Issues IS&T Scientific Visualization Tutorial – Spring 2010 • Compression • None, Lossless, or Lossy • Huge difference – 100 to 1 file size • Image Size/Resolution • Pixels vs. DPI (Dots per inch) • Web or Printing • Web support – JPEG, PNG, GIF • Color Depth • 24bit vs. 8bit – much less of an issue than it used to be

  5. Image Files - Formats IS&T Scientific Visualization Tutorial – Spring 2010 • JPEG – Web, 24bit, Lossy, Small file size • PNG – Web, 24bit • GIF – Web, 8bit, Color lookup table • TIFF, RGB, PPM – 24bit, Large file size, High quality • PSD – Photoshop’s format • Editable text, Layers, etc… • RAW – Digital camera formats, multiple • MANY others

  6. Image Files - Applications IS&T Scientific Visualization Tutorial – Spring 2010 • Viewing, Resizing, Manipulating Images • Adobe Photoshop • Windows/Macintosh • GUI, Very powerful, Expensive • Most popular general image editing package • XV • Mostly an image viewer but some editing capability • GUI, Linux, Free, Easy to use, No longer being updated • ImageMagick • Command-line tools • Linux, Free

  7. Adobe Photoshop IS&T Scientific Visualization Tutorial – Spring 2010

  8. XV IS&T Scientific Visualization Tutorial – Spring 2010

  9. ImageMagick IS&T Scientific Visualization Tutorial – Spring 2010 • Add a blue border around image (expand?, replace?, shrink?) • convert -border 10x10 -bordercolor "#6699ff" fan.png fan2.png • Add a caption/attribution • convert -font helvetica -fill red -pointsize 14 -draw 'text 446,404 "sondak@bu.edu"' fan2.png fan3.png

  10. ImageMagick - Tools IS&T Scientific Visualization Tutorial – Spring 2010 • Convert • Convert image formats. • Many image transformations available – scale, rotate, text, artistic filters • Display • Import • Screen capture under Linux • Identify • Find out characteristics of image • Composite • Composite multiple images together

  11. Batch Processing IS&T Scientific Visualization Tutorial – Spring 2010 • Working with a set or sequence of images • All images generally must be the same size • Adobe Photoshop • Recording and applying actions • Perl (or another computer language) • Extremely flexible but requires programming background or help • Augments command-line tools such as ImageMagick

  12. Movies IS&T Scientific Visualization Tutorial – Spring 2010 • ImageMagick (Animated GIFs only) • convert -delay 20 –loop 0 file*.gif anim.gif • animate anim.gif • Adobe Premiere • Movies • Displaying on computer or DVD? • Formats – QuickTime or AVI • Adobe Encore • DVDs • Menus, Controls, Chapters, etc…

  13. Images in Publications IS&T Scientific Visualization Tutorial – Spring 2010 • Resolution • Web – generally around 100 DPI • Print – generally 600 DPI – match journal specifications • Re-render image at very large scale. Do not just scale up. • File Format • Use a lossless 24-bit color format such as TIFF or PNG • Color Space • Web – RGB (standard) • Print – CMYK • Printing • Color gamut – Additive vs. subtractive color

  14. Working with Image Files - Questions? Aaron Fuegi aarondf@bu.edu http://scv.bu.edu/documentation/tutorials/ImageFiles/ IS&T Scientific Visualization Tutorial – Spring 2010

More Related