Transcript Introduction to Animation
Working with Image Files Aaron Fuegi [email protected]
IS&T Scientific Visualization Tutorial – Spring 2010
Working with Image Files - Topics
Image Files
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Compression, Resolution, Formats, etc...
Applications
Batch processing
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Working with image sets or sequences
Movies
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MPEG, DVD
Publications
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Resolution Color space
IS&T Scientific Visualization Tutorial – Spring 2010
Image Files
• PPM Image File – 24 bit color, 3 pixels by 3 pixels
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
IS&T Scientific Visualization Tutorial – Spring 2010
Image Files - Issues
Compression
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None, Lossless, or Lossy Huge difference – 100 to 1 file size
Image Size/Resolution
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Pixels vs. DPI (Dots per inch) Web or Printing Web support – JPEG, PNG, GIF
Color Depth
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24bit vs. 8bit – much less of an issue than it used to be
IS&T Scientific Visualization Tutorial – Spring 2010
Image Files - Formats
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
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Editable text, Layers, etc… RAW – Digital camera formats, multiple
MANY others
IS&T Scientific Visualization Tutorial – Spring 2010
Image Files - Applications
Viewing, Resizing, Manipulating Images
Adobe Photoshop
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Windows/Macintosh GUI, Very powerful, Expensive Most popular general image editing package
XV
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Mostly an image viewer but some editing capability GUI, Linux, Free, Easy to use, No longer being updated
ImageMagick
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Command-line tools Linux, Free
IS&T Scientific Visualization Tutorial – Spring 2010
Adobe Photoshop
IS&T Scientific Visualization Tutorial – Spring 2010
XV
IS&T Scientific Visualization Tutorial – Spring 2010
ImageMagick
Add a blue border around image (expand?, replace?, shrink?)
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convert -border 10x10 -bordercolor "#6699ff" fan.png fan2.png
Add a caption/attribution
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convert -font helvetica -fill red -pointsize 14 -draw 'text 446,404 "[email protected]"' fan2.png fan3.png
IS&T Scientific Visualization Tutorial – Spring 2010
ImageMagick - Tools
Convert
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Convert image formats.
Many image transformations available – scale, rotate, text, artistic filters
Display
Import
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Screen capture under Linux
Identify
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Find out characteristics of image
Composite
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Composite multiple images together
IS&T Scientific Visualization Tutorial – Spring 2010
Batch Processing
Working with a set or sequence of images
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All images generally must be the same size
Adobe Photoshop
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Recording and applying actions
Perl (or another computer language)
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Extremely flexible but requires programming background or help
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Augments command-line tools such as ImageMagick
IS&T Scientific Visualization Tutorial – Spring 2010
Movies
ImageMagick (Animated GIFs only)
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convert -delay 20 –loop 0 file*.gif anim.gif
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animate anim.gif
Adobe Premiere
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Movies Displaying on computer or DVD?
Formats – QuickTime or AVI
Adobe Encore
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DVDs Menus, Controls, Chapters, etc…
IS&T Scientific Visualization Tutorial – Spring 2010
Images in Publications
Resolution
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Web – generally around 100 DPI Print – generally 600 DPI – match journal specifications
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Re-render image at very large scale. Do not just scale up.
File Format
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Use a lossless 24-bit color format such as TIFF or PNG
Color Space
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Web – RGB (standard) Print – CMYK
Printing
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Color gamut – Additive vs. subtractive color
IS&T Scientific Visualization Tutorial – Spring 2010
Working with Image Files - Questions?
Aaron Fuegi [email protected]
http://scv.bu.edu/documentation/tutorials/ImageFiles/ IS&T Scientific Visualization Tutorial – Spring 2010