Barco HDF Use And Installation Manual page 166

12. Alignment
The use of warping adjustment leads to image quality loss! The more geometry adjustment is applied, the
more quality loss.
Moving an anchor point causes pixels in the same region to be moved gradually with this one pixel, depending on their distance to
it. The size of the region of impact depends on the anchor point: some anchor pixels have impact on the full image, while others
have impact on a small area only. The full image is divided in 33 x 33 regions. The smallest region of impact is one of these 1089
regions.
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Image 12-32
33 x 33 regions in an image
Warp adjustment is divided in six modes:
• 2 x 2 (highest mode);
• 3 x 3;
• 5 x 5;
• 9 x 9;
• 17 x 17;
• 33 x 33 (lowest mode).
The six modes represent 21 levels, each level representing its own group of anchor points.
Level 4 Level 5
Level 7 Level 8
Level 11 Level 12 Level 13
Level 16
Image 12-33
Level hierarchy
The hierarchy of these levels is very important: each level interacts with all lower levels. Adjusting a point on a certain level affects
the points in all or some of the lower levels. The impact depends on the level itself. Therefore it is important to adjust the geometry
starting from level one and going down to lower levels as required. In practice it will not be needed to adjust the anchor points of
levels 7 and lower.
In 2 x 2 mode, we only have one level, including all four (2 x 2) anchor points, being the image corners. This mode is especially
used to correct horizontal and vertical keystone.
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2 x 2
Level 1
3 x 3
Level 2 Level 3
5 x 5
Level 6
Level 9
9 x 9
Level 10
Level 14 Level 15
Level 17 Level 18
Level 19 Level 20
Level 21
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17 x 17
33 x 33
R5905158 HDF SERIES 16/06/2015