Prediction error filters to enhance differences

Planewave migration

As demonstrated in the last section the PEF method has the ability to highlight subtle differences in images. In this section, I apply the methodology to 3-D plane-wave migrated cubes. The first uses a conventional scheme, the second uses the tilted-coordinate approach described in Shan and Biondi (2007). I broke the image into 30x30x30 patches and used a 3-D PEF that was 8x3x3 in size.

Figure 11 shows three orthogonal slices through a volume migrated with a conventional planewave migration algorithm. Note the salt structure top is poorly delineated in the inline section. Figure 12 shows the same three orthogonal slices using a tilted planewave migration scheme. Note how salt top is significantly better delineated. Figure 13 shows the result of apply the PEF scheme compared the two 3-D migrated cubes. In the depth slice, the salt structure is highlighted. In addition, several faults become evident. The inline panel and crossline panel highlight the salt top. A subtle fault feature is visible in the crossline and a high-spatial frequency even is evident in the inline. Figure 14 shows the result of using the histogram methodology. The method proves generally ineffective in highlighting any differences other than the salt top.

notiltsame
Figure 11. Three orthogonal slices through a migrated cube using a conventional planewave migration algorithm.

tilt
Figure 12. The same slices seen in Figure 11, now through a volume migrated with a tilted-coordinate planewave migration algorithm.

comp-good
Figure 13. The same slices seen in Figure 11- 12 through a volume created by applying equation 5 to the volumes shown in the previous two figures. Note the highlighting of the salt reflection along with several faults.

comp-histo
Figure 14. The same slices seen in Figure 11- 13 through a volume created by applying the histogram matching approach. Note how the salt top is visible but the fault features seen Figure 14 are not.

Prediction error filters to enhance differences