image based motion blur for stop motion animation n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Image-Based Motion Blur for Stop Motion Animation PowerPoint Presentation
Download Presentation
Image-Based Motion Blur for Stop Motion Animation

Loading in 2 Seconds...

play fullscreen
1 / 16

Image-Based Motion Blur for Stop Motion Animation - PowerPoint PPT Presentation


  • 122 Views
  • Uploaded on

Image-Based Motion Blur for Stop Motion Animation. Gabriel J. Brostow Irfan Essa SIGGRAPH ‘01. First: Stop Motion Animation. Create a Physical Scene Insert Characters / Objects Change Scene Slightly Record Frame and Repeat. Why do we want Motion Blur?. For fast moving objects

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 'Image-Based Motion Blur for Stop Motion Animation' - janeeva


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
image based motion blur for stop motion animation

Image-Based Motion Blur for Stop Motion Animation

Gabriel J. Brostow

Irfan Essa

SIGGRAPH ‘01

first stop motion animation
First: Stop Motion Animation
  • Create a Physical Scene
  • Insert Characters / Objects
  • Change Scene Slightly
    • Record Frame and Repeat
why do we want motion blur
Why do we want Motion Blur?
  • For fast moving objects
    • Prevent time aliasing
    • Need for a tool to convey fast motions
  • Realistic Perception
    • Notice the absence
overview
Overview:
  • Segmentation
  • Rigid “blob” tracking
  • Flow Correction
  • Rendering Blur
  • Results
scene segmentation
Scene Segmentation:
  • Grouping the pixels to be tracked:
    • Ib : background image
    • If : image of current frame
    • Im : image of moving pixels, where:
  • Each continuous region of pixels within Im is considered to be a “blob”
pixel transformations
Pixel Transformations:
  • Determining frame-by-frame pixel mapping is still an on-going research problem
    • They use a two-pass approach

One Commercial Method

Their Method

blob tracking
Blob Tracking:
  • Perform similarity search between each blob b in Im(i) and Im(i+1)
  • Reduce search space through assumptions:
    • Blob’s appearance not greatly affected by scale
    • Rotation of blob can be determined by absolute orientation
blob tracking cont
Blob Tracking (cont.):
  • For each b(i), template-match against Im(i+1) through the normalized cross correlation NCC, where:
  • Interpolate a vector mapping for pixels from frame i to i+1
flow correction
Flow Correction:
  • Have an estimate for 2-D transformations by the scene’s blobs
  • Ir(i+1): estimate of If(i+1) generated by applying If(I)’s computed vectors
    • Ideal 2-D: Ir(i+1) = If(i+1), but other effects
    • Optical flow finds motion vectors to warp Ir(i+1) to If(i+1)
rendering blur
Rendering Blur:
  • Linearly interpolate pixel paths (L(t))
  • User defines shutter speed (S)
  • Determine time spent in each cell (w(x,y))
  • Distribute pixel (C)
rendering blur cont
Rendering Blur (cont.):
  • IAft(ti) : Motion of If(ti) from ti to ti + S/2
  • Get IBef(ti): ti to ti - S/2
  • Pixel-wise average these occupancy maps
  • Some pixels have few or no pixels move through them
results
Results:
  • Examples
    • Representative input and output pair
results1
Results:
  • Examples
    • Affects of different shutter speeds
results2
Results:
  • Examples
    • Shutter speed vs. interpolation
results3
Results:
  • Examples
    • Problems with shadows