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Interlacing

In some cases, image sensor data do not correspond to the same instant. Image rows are subdivided into two disjoint sets, each of them representing a field: all the rows of a single field share the same time but the two fields correspond to different instants. If the sensor is stationary and the scene is static a single image can be reconstructed by collating the two fields. If the camera is moving, or the scene is not static, the single image resulting from the integration of two fields exhibits noticeable artifacts.



Codelet 3 Interlaced image generation (../TeMa/R/tm.interlaceImage.R)

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Interlacing impacts on template matching: line offset results in image differences that are not compensated by the matching process. As the following code snippet shows, the effect increases with the time delta of the two image fields and with the amount of local image structure (edges are the major sources of difference).
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Figure 2.6: Interlacing results in image differences that increase with image field time lapse (top) and with the amount of local image structure (bottom).
[width=10cm]figures/interlaceDelta.jpg
[width=10cm]figures/interlaceDeltaImage.jpg


next up previous
Next: Image resampling Up: Digital imaging artifacts Previous: Demosaicing
Roberto Brunelli 2008-11-25