Images / Cines

Outline

Vector Graphics
- Consists of Lines, Curves, Geometric Shapes
- Used in CAD/CAM - 2D Surfaces in 3D Space
- e.g. PICT - Vector Graphics and Raster
Matrix, Raster
- Raw, Bitmapped
  - Bits/pixel - 8, 16, 24, 32, 36
  - Rows, Columns, Frames
- Nuclear Medicine
  - Interfile, DICOM (uch!)
  - Header (patient name, format, etc.) + Image
- General Purpose
  - GIF, TIFF, JPEG, Kodak PhotoCD
  - Header + Image (often compressed raw)
- Presentation (Slide, Notes)
  - Microsoft PowerPoint, Adobe Persuation
  - General Purpose Image and Vector Graphics Imbedded in Slide
- Desktop Publishing
  - Adobe PageMaker
  - General Purpose Image and Graphics Imbedded in Page Layout for Printing
- Movie
  - Multiframe TIFF
  - MPEG-1, MPEG-2 (HDTV), QuickTime
    - Image Tracts, Sound Tracts, and Timing

Draw - lines & curves - Vector Graphics - e.g. Adobe Illustrator
Paint - Blobs - Matrix Format
Image Processing - e.g. Adobe PhotoShop
- Crop, Resampling, Pixel Density, Brightness, Contrast, Smooth, etc.
Annimation
Movie - e.g. Adobe Premier

Raster Size
- Rows, Columns, Frames
- Resolution Less than or Equal to Raster Size
Intensity (Depth)
- Bits per Pixel
Pixel Density
- Grayscale often 72 Pixels per Inch = 1Pixel per Point
- Halftone often 300, 600, or 1200 Dots per Inch
Image Size
- Inches, Centimeters, or Points
- Density = Raster Size / Image Size

Select Interesting Images (Cines)
Capture in General Format
- Best - Translate from Nuclear Medicine Format to TIFF or GIF
- Worst - Digitize
  - BIH - 512x512 Frame Grabber
  - DFCI - Flat Bed Scanner
  - PhotoCD - Excellant for Existing Slides
Process Image
- e.g. PhotoShop - Static Images
  - Invert
  - Crop
  - Adjust Contrast
  - Reduce Raster Size
  - Clean Up
  - Add Arrows
  - Save as GIF or TIFF
- e.g. Premier - Cines - Save as MPEG
Encapsilate Image
- In Slide Format
- For Display
- In Teaching File
Make Slides - DFCI esp. Mac, BIH esp. IBM, BWH library
Presentation
- Slides are Good for Static Images
- NIH Image (multiframe TIFF) is Good for Cine or Online Windowing

Powers of 2
- 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, ...
- Often Related to Matrix Dimensions in Nuclear Medicine
- Rarely Related to Matrix Dimensions for Picture Processing
Raster Display
- Computer (4:3) - 640x480 (14"), 832x624 (15"), 1024x768 (17"), 1152x870 (20"), 1280x1024 (21"), 1600x1280 (25")
- HDTV (16:9) - 1280x720, 1920x1080
Byte = 8 bits
- 8 bit = 256 values, 16 bit = 64k values, 24 bit = 16M values, 32 bit = 4G values
Number of Colors
- 8 bit (256) - grayscale display, indexed color
- 16 bit (Thousands) - QuickTime, indexed color
- 24 bit (Millions) - RBG (8 bits per color), PhotoCD (also 8 & 15)
- 30 bit - HDTV (10 bits per color)
- 32 bit - JPEG (also 4, 8, 15, 16, & 24)
- 36 bit - RBG (12 bits per color)
V-ram Size (256, Thousands, Millions)
- 14" - 640x480 = 300 k - 0.29, 0.59, 0.88 M
- 15" - 832x624 = 507 k - 0.50, 0.99, 1.49 M
- 17" - 1024x768 = 768 k - 0.75, 1.5, 2.25 M
- 20" - 1152x870 = .96 M - 0.96, 1.91, 2.86 M
- 21" - 1280x1024 = 1.25 M - 1.25, 2.5, 3.75 M
- 25" - 1600x1280 = 1.95 M - 1.95, 3.91, 5.86 M
- - 1280x720 = 900 k - 0.88, 1.76, 2.64 M
- - 1920x1080 = 1.98 M - 1.98, 3.96, 5.93 M
Pixel Density
- 14" - 640x480 - 57 Pixels/Inch
- 15" - 832x624 - 69 Pixels/Inch
- 17" - 1024x768 - 75 Pixels/Inch
- 20" - 1152x870 - 72 Pixels/Inch
- 21" - 1280x1024 - 76 Pixels/Inch
- 25" - 1600x1280 - 80 Pixels/Inch

A good source of color format information is Poynton's Color Technology Page.
A good source of HDTV informations is Poynton's Grand Alliance Mirror.

GIF
- Good Compression for Logos, Sparse Data
- The Web Likes GIF the Best
- Lossless
- Allows Only 8 Bits per Pixel
JPEG
- Good Compression for Natural Sceens
- Lossy
TIFF
- Good Compression for Halftone
- Multi Frame for Cines
- NIH Image Works Best with TIFF
MPEG-1 & MPEG-2
- Standard Movie Format
- MPEG-2 used in HDTV

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