Deinterlace
The Deinterlace module will un-interlace an image produced by a camera or video source that has
weaved the even and odd rows of two images together. This weaving was done to reduce the
overall bandwidth required for the transmission of images but causes "jaggies" in images
when reproduced on a computer for analysis. Note that this only valid for moving images
as an interlaced image is in fact two images spliced together. If you are using such a
video source for a static scene or one where the camera does not move then interlacing
will not be an issue as the current and next frame will be so similar that the interlacing
will not be noticeable.
For those video sources that are filming rapid movements the deinterface module will help
to reduce or eliminate those artifacts. Due to the interlacing being two images, each image
only has half the number of rows that it normally does. This causes resolution issues when
trying to compensate for interlacing by separating them. The missing row in each image
needs to be artificially created in order for a "reasonable" approximation of the original
frame to be created. Note that if you have the possibility to not use an interlaced video
source we recommend you attempt that route as the resolution and information content of those
images are always superior to their interlaced version (about 2x).
Interface
Instructions
1. Technique - Select the Appropriate Technique to use to eliminate the jaggies.
Eliminate - Removes the even or odd rows of the image. In effect this is ignoring one of
the frames.
Side by Side - show the two deinterlaced frames next to each other.
Blend - blurs the two frames into a less jaggied version. Note this will not effect
the frame rate and in effect causes a frame to be lost. This does have the nice effect
of causing motion blur where motion is present.
Duplicate - simply duplicates the even or odd row to create the missing row in
each image. This is the fastest way to separate each image and double the frame rate.
Interpolate - Instead of just copying one row to the next the interpolation technique
will smooth the transition from one actual row to the next by creating the new row as
an interpolation (average) of the previous and next row. This causes smoother row transitions
than the duplicate technique but with the addition of some blurring.
Motion - If one row (even) is similar enough to the next interlaced row (odd) then its value is used. Otherwise
if the next row is above the difference threshold then the interpolated value of the two rows (even+even2)
is used. This has the advantage of providing full resolution on parts of the image that are not
in motion or do not include a moving object.
Median - The median value of the interpolated pixel, the current pixel (even) and the next row (odd) is used.
2. Options - Select which row field you want to use. Odd specifies that only the odd row is deinterlaced. Even
specifies that the even row is used. Double Frame rate means that two frames are extracted from a single interlaced image.
Each frame is then added as a new frame into the pipeline. Thus you can increase
the frame rate of the video by selecting this option. Please note that while the frame rate will
be increased the actual image content is 50% of what reality is.
Example
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