graphics and still images
Download
Skip this Video
Download Presentation
Graphics and Still Images

Loading in 2 Seconds...

play fullscreen
1 / 32

Graphics and Still Images - PowerPoint PPT Presentation


  • 372 Views
  • Uploaded on

Graphics and Still Images John H. Krantz Hanover College Outline Graphics Types Developing with Paint Images File Types Acquiring Using ImageJ Basics Advanced Graphics vs. Images Some definitions: mine for clarity here: Graphics Def: computer generated or drawn by you.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Graphics and Still Images' - paul


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
graphics and still images

Graphics and Still Images

John H. Krantz

Hanover College

outline
Outline
  • Graphics
    • Types
    • Developing with Paint
  • Images
    • File Types
    • Acquiring
    • Using ImageJ
      • Basics
      • Advanced
graphics vs images
Graphics vs. Images
  • Some definitions: mine for clarity here:
    • Graphics Def: computer generated or drawn by you.
    • Image: scanned, captured, take photograph or an graphic file not generated by you.
    • Difference:
      • In a graphic, you can directly manipulate the elements because you drew them – Sprites
      • In an image, you can manipulate pixels but not directly the elements. This has a great impact.
graphic types
Graphic Types
  • Storing Formats:
    • Bitmap (bmp, PCT, Tiff) – big, not good for web
    • Compressed
      • Graphic Interchange Format (Gif) can animate
        • 8 bits of color – palette – no spatial compression
        • Can be some legal issues – make sure the generator legally can generate GIF’s
        • Generally best compression for simple graphics
        • Can generate transparent regions
      • JPG
        • Generally better for images and photos
        • Spatial not color compression, can distort image spatially.
        • Now can animate as well.
developing with imagej
Developing with ImageJ
  • Free
  • Very simple but easy
  • Access to pixels
  • No anti-aliasing
    • Downside: jaggies
    • Upside: in complete control of graphics
  • Can store in Lots of Formats
try some
Try some
  • Basic Graphics Objects
  • Cutting and Pasting
    • Transparency
  • Adding Text
  • Saving in Different Format
    • Transparency (set in web page program).
  • Reading Different Formats
image types
Image Types
  • Same as with graphics
  • JPG is generally better in terms of compression ratio, smaller files, for images
  • For complex images, minor spatial distortions will be hidden.
acquiring
Acquiring
  • Scanning
    • Flatbed gives best quality.
    • Use 35 MM film for pictures – best resolution
    • Scan at a high level and sample down later
    • Any model seems good this day.
digital cameras
Digital Cameras
  • No loss in Scanning
  • CCD
  • 3.1 Megapixel at least if need photo quality
    • there are 5 megapixel
    • Can use lower quality if only need web.
  • Easy to download
  • Good in low light
taking photos digitally
Taking Photos Digitally
  • Focusing: Automatic and Manual
    • Regular focus
    • Macro – allows focusing up close
    • Spot Focus: focus is determined by point
  • Shutter Speed
  • Zoom:
    • Do not use digital zoom – if need more zoom, do it on computer later
    • On my default is off except for movies
taking pictures cont
Taking Pictures (cont.)
  • White Balance, controls for our color constancy
    • Effect of the Illuminant
  • Flash:
    • often I keep it off.
  • Image Size:
    • I keep at standard (full pixel density, some JPG compression). Balance between image quality and ability to store on disk ~ 1 Meg/picture
use of flash
Use of Flash

Flash No Flash

editing images with imagej
Editing Images with ImageJ
  • Free at: http://rsb.info.nih.gov/ij/index.html
  • Overview
    • Java program
    • Interface a bit awkward because not free (no shortcuts)
    • Expandable via plug-ins
  • Covers all basic editing and many advanced
basic editing
Basic Editing
  • Most Important Command: Revert
    • Under the File Menu
    • Ctrl-z is undo but only one step.
  • Suggest do “save as” or make copy first so don’t destroy original
  • Resize for web: under Image: Scale or Adjust: Size
basic editing18
Basic Editing
  • Selecting a region
  • Clear
  • Clear outside
  • Cropping
  • Rotating and Flipping
  • Adjusting Brightness and Contrast
  • Thresholding
an example
An Example
  • How symmetrical am I?
    • The original image
select the region
Select the region
  • I used the rectangular region – easier
  • Centered on some feature in middle – find the x value (I used a gap in my teeth)
crop and flip
Cropped

Flipped Horizontally

Crop and Flip
cut and paste
Cut and Paste

Final Picture

  • Reopen original face
  • Select all of half face
  • Paste into other
  • Adjust location
paste control
Paste Control
  • Copy
  • Blend
paste control24
Paste Control
  • Difference
  • Transparent
converting images
Converting Images
  • Save as for Image Types – use GIF or JPG
    • Must add extension, it is not added automatically
    • Always use save as to save anything other than a TIFF
      • This is a full color uncompressed image
converting images26
Converting Images
  • Converting Color Depth or to Grayscale image
    • 8-bit, 16-bit, 32-bit are grayscale
    • 8-bit RGB and RGB are color
    • It is not possible to arbitrarily convert images
      • but ImageJ gives table of possible conversions
      • e.g. can only convert JPG to and 8bit grayscale.
adding to images
Adding to Images
  • Setting Colors
    • Edit: Options: Foreground Color
    • Image: Colors
  • Adding Text
    • Set font in
      • Edit: Options: Font
      • Draws in selected color
adding to images28
Adding to Images
  • Drawing a basic graphics object
    • Draw width:
      • Edit: Options: Line Width
    • Select shape
    • Put shape on image
    • Edit: Draw or ctrl-D
  • Filled regions
    • Same as above, but:
      • line width not important
      • Use Edit: Fill or ctrl-F
filtering images
Filtering Images
  • Under the Process menu
    • Sharpen: more edges
    • Smooth: dull details
filtering images30
Filtering Images
  • Edges: finds them – so type of outline
filtering images31
Filtering Images
  • Gaussian: blurs
    • Amount of blur depends upon the standard deviation (called radius)
some useful plugins
Some Useful Plugins
  • Some have limits but as developments go, you will be able to get new ones without these limits
  • Can build your own
    • Uses Java
    • instructions on web page
  • RGB Recolor
  • Inverter
  • File opener: multiple files
  • AVI writer
ad