**3.4 Raster and star refinement**

The refinement is performed when the distance of the motion vector previously obtained is different to 0. There are mainly two refinement types:

• Raster refinement

The best point obtained from the previous steps corresponds to the start point of the star refinement. It can be performed using a diamond or a square pattern with distances ranging from "search range" to one. In each iteration, the distance is divided by 2, and when the distance will be equal to one, two adjacent point searches are performed, and then the process is stopped.

• Star refinement

**Figure 6.** *Raster search pattern when iRaster = 4.*

*Fast Motion Estimation's Configuration Using Diamond Pattern and ECU, CFM,… DOI: http://dx.doi.org/10.5772/intechopen.86792*

In this step, the selected point obtained from the previous steps corresponds to the start point of the star refinement. In each iteration, the distance is divided by two, and when the distance will be equal to one, two adjacent point searches are

**Figure 7.** *The used TZSearch algorithm.*

**3.3 Raster search**

*Digital Imaging*

overdone.

equal to 4.

This step consists of choosing the distance which corresponds to the greatest matched point from the previous search. Three cases according to this distance

In the configuration file, "iRaster" represents a changeable variable not to be

• BestDistance > iRaster is agreed correctly; a raster scan is achieved using the iRaster value as the length step. If difference obtained from the starting station to the MV from the first level is besides large, this step is preceded. This step is

**Figure 6** shows an example of a full search algorithm with iRaster which is

The refinement is performed when the distance of the motion vector previously

The best point obtained from the previous steps corresponds to the start point of the star refinement. It can be performed using a diamond or a square pattern with distances ranging from "search range" to one. In each iteration, the distance is divided by 2, and when the distance will be equal to one, two adjacent point

denoted as "BestDistance" are summarized as follows:

computed on the entire search window.

**3.4 Raster and star refinement**

• Raster refinement

• Star refinement

**Figure 6.**

**16**

*Raster search pattern when iRaster = 4.*

• The process is stopped when "BestDistance" = 0.

• A refinement is needed when 1 < "BestDistance" < iRaster.

obtained is different to 0. There are mainly two refinement types:

searches are performed, and then the process is stopped.

applied to determine the best estimated MV which gives the minimum of SAD (**Figure 7**).
