Camera Link Tap Geometry
Image Geometrical Properties
The relevant geometrical properties required to reconstruct the image are:
- Vantage point: an enumerated type of parameter that specifies the position of the pixel with coordinate X=1, Y=1 in the scene. {Top-Left, Top-Right, Bottom-Left, Bottom-Right}. Default is Top-Left.
- ImageWidth: an integer type of parameter declaring the image width expressed in pixels.
- ImageHeight: an integer type of parameter declaring the image height expressed in pixels. This parameter is irrelevant in case of line-scan or TDI cameras.
- TapGeometry: an enumerated type of parameter that summarizes following properties for each tap:
- X Start: X-coordinate of the first pixel column
- Y Start: Y-coordinate if the first pixel row
- X End: X-coordinate of the last pixel column
- Y End: Y-coordinate of the last pixel row
- X Step: difference of X-coordinates between consecutive pixel columns; X-step is positive when X-coordinates are increasing along a row; it is negative otherwise.
- Y Step: difference of Y-coordinates between consecutive pixel rows; Y-step is positive when Y-coordinates is increasing at the end of a line; it is negative otherwise.
Naming Convention
A tap geometry for area-scan camera is designated by: <TapGeometry>-<TapGeometry>
A tap geometry for line-scan or TDI-line-scan camera is designated by : <TapGeometry>
TapGeometryX is designated by <RegionX>X(<TapX>)(<ExtX>)
- <RegionX>: an integer in range {1, 2, 3, 4, 8, 10} declaring the number of regions encountered across horizontal direction. A region is a rectangular area of adjacent pixels that are transferred in a raster-scan order through one or several taps. In case of several taps, adjacent pixels are transferred simultaneously.
- <TapX>: an integer in range {2, 4, 8, 10} declaring the number of consecutive pixels across horizontal direction that are output simultaneously from a region.
This field is omitted when all pixels are in the same column. - <ExtX>: a letter declaring the location of the pixels extractors across horizontal direction.
This field is omitted when all pixel extractors are all at the left of each region.
Letter E indicates that pixel extractors are at both ends of the line.
Letter M indicates that pixel extractors are at middle of the line.
Letter R indicates that the pixel extractors are all at the right of each region
For other values, refer to the tabular description.
TapGeometryY is designated by <RegionY>Y(<TapY>)(<ExtY)>)
- <RegionY>: an integer in range {1, 2} declaring the number of regions encountered across vertical direction.
- <TapY>: an integer declaring the number of consecutive pixels across vertical direction that are output simultaneously from a region.
This field is omitted when all pixels are in the same line. - <ExtY>: a letter declaring the location of the pixels extractors across vertical direction. Value E indicates that pixel extractors are at top and bottom lines.
This field is omitted when all pixel extractors are at all the top line.
Examples
- 1X-1Y designates an area-scan camera having 1 region across X and 1 region across Y. The pixels are delivered one at a time on a single tap beginning with the leftmost pixel of the top line.
- 1X4 designates a line-scan camera having 1 region across X. Four adjacent pixels are delivered simultaneously on 4 taps beginning with the leftmost pixels.
- 4X1 designates a line-scan camera having 4 regions across X. Four non-adjacent pixels are delivered simultaneously on 4 taps; all taps begins with the leftmost pixel.
Allocation of Taps to Ports
The camera taps are indexed using following conventional sorting rule: first by increasing values of YStart, then by increasing value of XStart. The tap T1 is the camera tap that exhibits the smallest XStart for the smallest YStart.
Restrictions
- All zones have the same size.
- Zones are not overlapping.
- All zones have the same number of taps.
- All taps are carrying the same amount of pixels.
Tap Geometrical Properties
X properties – Tabular definitions
The following tables define the geometrical properties along the X direction.
One tap – 1X
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W |
1 |
Two taps – 1X2
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W-1 |
2 |
Tap2 |
2 |
W |
2 |
Two taps – 2X
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/2 |
1 |
Tap2 |
W/2+1 |
W |
1 |
Two taps – 2XE
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/2 |
1 |
Tap2 |
W |
W/2+1 |
-1 |
Two taps – 2XM
Tap# |
X Start |
X End |
X Step |
Tap1 |
W/2 |
1 |
-1 |
Tap2 |
W/2+1 |
W |
1 |
Two taps – 2XR
Tap# |
X Start |
X End |
X Step |
Tap1 |
W/2 |
1 |
-1 |
Tap2 |
W |
W/2+1 |
-1 |
Four taps – 1X4
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W-3 |
4 |
Tap2 |
2 |
W-2 |
4 |
Tap3 |
3 |
W-1 |
4 |
Tap4 |
4 |
W |
4 |
Four taps – 2X2
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/2-1 |
2 |
Tap2 |
2 |
W/2 |
2 |
Tap3 |
W/2+1 |
W-1 |
2 |
Tap4 |
W/2+2 |
W |
2 |
Four taps – 2X2E
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/2-1 |
2 |
Tap2 |
2 |
W/2 |
2 |
Tap3 |
W-1 |
W/2+1 |
-2 |
Tap4 |
W |
W/2+2 |
-2 |
Four taps – 2X2M
Tap# |
X Start |
X End |
X Step |
Tap1 |
W/2-1 |
1 |
-2 |
Tap2 |
W/2 |
2 |
-2 |
Tap3 |
W/2+1 |
W-1 |
2 |
Tap4 |
W/2+2 |
W |
2 |
Four taps – 4X
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/4 |
1 |
Tap2 |
W/4+1 |
W/2 |
1 |
Tap3 |
W/2+1 |
3W/4 |
1 |
Tap4 |
3W/4+1 |
W |
1 |
Four taps – 4XE
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/4 |
1 |
Tap2 |
W/4+1 |
W/2 |
1 |
Tap3 |
3W/4 |
W/2+1 |
-1 |
Tap4 |
W |
3W/4+1 |
-1 |
Four taps – 4XR
Tap# |
X Start |
X End |
X Step |
Tap1 |
W/4 |
1 |
-1 |
Tap2 |
W/2 |
W/4+1 |
-1 |
Tap3 |
3W/4 |
W/2+1 |
-1 |
Tap4 |
W |
3W/4+1 |
-1 |
Eight taps – 1X8
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W-7 |
8 |
Tap2 |
2 |
W-6 |
8 |
Tap3 |
3 |
W-5 |
8 |
Tap4 |
4 |
W-4 |
8 |
Tap5 |
5 |
W-3 |
8 |
Tap6 |
6 |
W-2 |
8 |
Tap7 |
7 |
W-1 |
8 |
Tap8 |
8 |
W |
8 |
Eight taps – 4X2
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/4-1 |
2 |
Tap2 |
2 |
W/4 |
2 |
Tap3 |
W/4+1 |
W/2-1 |
2 |
Tap4 |
W/4+2 |
W/2 |
2 |
Tap5 |
3W/2+1 |
3W/4-1 |
2 |
Tap6 |
3W/2+2 |
3W/4 |
2 |
Tap7 |
3W/4+1 |
W-1 |
2 |
Tap8 |
3W/4+2 |
W |
2 |
Eight taps – 4X2E
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/4-1 |
2 |
Tap2 |
2 |
W/4 |
2 |
Tap3 |
W/4+1 |
W/2-1 |
2 |
Tap4 |
W/4+2 |
W/2 |
2 |
Tap5 |
3W/4-1 |
W/2+1 |
-2 |
Tap6 |
3W/4 |
W/2+2 |
-2 |
Tap7 |
W-1 |
3W/4+1 |
-2 |
Tap8 |
W |
3W/4+2 |
-2 |
Eight taps – 8X
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
W/8 |
1 |
Tap2 |
W/8+1 |
2W/8 |
1 |
Tap3 |
2W/8+1 |
3W/8 |
1 |
Tap4 |
3W/8+1 |
4W/8 |
1 |
Tap5 |
4W/8+1 |
5W/8 |
1 |
Tap6 |
5W/8+1 |
6W/8 |
1 |
Tap7 |
6W/8+1 |
7W/8 |
1 |
Tap8 |
7W/8+1 |
W |
1 |
Eight taps – 8XR
Tap# |
X Start |
X End |
X Step |
Tap1 |
W/8 |
1 |
-1 |
Tap2 |
2W/8 |
W/8+1 |
-1 |
Tap3 |
3W/8 |
2W/8+1 |
-1 |
Tap4 |
4W/8 |
3W/8+1 |
-1 |
Tap5 |
5W/8 |
4W/8+1 |
-1 |
Tap6 |
6W/8 |
5W/8+1 |
-1 |
Tap7 |
7W/8 |
6W/8+1 |
-1 |
Tap8 |
W |
7W/8+1 |
-1 |
Ten taps – 1X10
Tap# |
X Start |
X End |
X Step |
Y Start* |
Y End* |
Y Step* |
Tap1 |
1 |
W-9 |
8 |
1 |
H |
1 |
Tap2 |
2 |
W-8 |
8 |
1 |
H |
1 |
Tap3 |
3 |
W-7 |
8 |
1 |
H |
1 |
Tap4 |
4 |
W-6 |
8 |
1 |
H |
1 |
Tap5 |
5 |
W-5 |
8 |
1 |
H |
1 |
Tap6 |
6 |
W-4 |
8 |
1 |
H |
1 |
Tap7 |
7 |
W-3 |
8 |
1 |
H |
1 |
Tap8 |
8 |
W-2 |
8 |
1 |
H |
1 |
Tap9 |
9 |
W-1 |
8 |
1 |
H |
1 |
Tap10 |
10 |
W |
8 |
1 |
H |
1 |
Y properties – Tabular definitions
The following tables define the geometrical properties along the Y direction.
One tap – 1Y
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
H |
1 |
Two taps – 1Y2
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
H-1 |
2 |
Tap2 |
2 |
H |
2 |
Two taps – 2YE
Tap# |
X Start |
X End |
X Step |
Tap1 |
1 |
H/2 |
1 |
Tap2 |
H |
H/2+1 |
-1 |