Edge Blend procedure (continued)
6. Uplift black levels (optional).
If you do not need to uplift the black levels, skip
to step 8, Blend the images.
Switch all projectors to the Black Field test pattern.
The level of black will differ across the image as
shown in Fig. 1. Uplift the black levels using Edge
Blend > Black Level Uplift.
How to uplift black levels
Regions may be overlapped by two or four
projectors. An array will always contain regions
overlapped by at least two projectors.
• x2 overlaps
If your array only contains two-projector
overlaps, you need to uplift the black levels in
the unblended regions – the exact value will
depend on the projector, environment, etc.
Do not uplift black levels in the overlapping
region(s).
• x2 and x4 overlaps
Sometimes a region is overlapped by four
projectors. For example, in a two-by-two
segment setup, Array Width = 2 and
Array Height = 2, the region in the middle is
overlapped by all four projectors (as shown in
Fig. 1). If your array contains such regions, you
need to uplift black levels roughly four times in
the unblended regions, and roughly double in
the regions overlapped by two projectors.
31 2
1
Unblended region
This region is not overlapped. Black level should be raised by the
maximum overlap occurring within the image, therefore the value of
Black Level Uplift should be the highest here.
2
x2 overlap
This section of the image is overlapped by two projectors, therefore the
correct amount of
Black Level Uplift should be roughly half the value of
uplift within the unblended region.
3
x4 overlap
This part of the image is overlapped by four projectors, therefore
Black
Level Uplift should not be applied.
Fig. 1 Different black levels
Notes