McalTransformCoordinateList

MIL_ID CalibrationOrImageId,	//in
MIL_INT64 TransformType,	//in
MIL_INT NumPoints,	//in
const MIL_DOUBLE *SrcCoordXArrayPtr,	//in
const MIL_DOUBLE *SrcCoordYArrayPtr,	//in
MIL_DOUBLE *DstCoordXArrayPtr,	//out
MIL_DOUBLE *DstCoordYArrayPtr	//out

)

Description

This function converts a list of coordinates from their pixel value to their world value (or vice versa). The conversion can be performed according to a calibration context, calibrated image, or corrected image.

Note that, if you changed the origin and/or orientation of the relative coordinate system (using McalRelativeOrigin() or McalSetCoordinateSystem()), world coordinates will be returned, or assumed to be given, with respect to this relative coordinate system.

This function converts the coordinates of a point by making a line connecting the center of the camera's lens with the point provided, and then finding the intersection of that line with the required plane. To convert an image pixel to a world point, this function defines a line connecting the center of the camera's lens with the image plane, and then returns the intersection of this line with the world plane.

However, if the image plane is not parallel to the relative coordinate system, due to the camera setup or a displacement of the relative coordinate system, not every point in the image plane will have a valid real-world equivalent. Three types of intersections can occur when transforming from the image plane to the world plane. If the specified point in the image plane corresponds to a point in front of the camera and in the relative coordinate system, that point in the relative coordinate system is returned. However, if the line traced through the specified point in the image plane does not intersect the XY (Z=0) plane of the relative coordinate system, M_INVALID_POINT is returned since there is no intersection. If the line's intersection with the XY (Z=0) plane of the relative coordinate system is behind the camera, then the mathematically computed value is returned, even though it is not the correct world location of the point specified in the image.

However, using M_NO_POINTS_BEHIND_CAMERA returns M_INVALID_POINT if the returned point is behind the camera.

Note that this function reference has not been updated for a MIL system added during a MIL update. Refer to the MIL system's release note to see if there is complementary information.

Parameters

This function is not supported on the selected boards.

Parameters

CalibrationOrImageId

Specifies the identifier of the calibration context, calibrated image, or corrected image. When an identifier of an image buffer is specified, the transformation uses the calibration context associated with this image.

If you are transforming the coordinates of a calibrated image, you can pass either its identifier or the identifier of its calibration context. However, if the coordinates being passed were obtained from a child buffer you must only pass the identifier of the child buffer.

TransformType

Specifies whether to perform a pixel-to-world or world-to-pixel conversion. This parameter must be set to one of the following values:

For specifying pixel-to-world or world-to-pixel
Value	Description
M_PIXEL_TO_WORLD +	Converts from pixel to world.
M_WORLD_TO_PIXEL +	Converts from world to pixel.

Combination constant for the values listed in For specifying pixel-to-world or world-to-pixel.

You can add the following value to the above-mentioned values to set the input and/or output as interlaced.

For optimizing:
Combination value	Description
M_PACKED	Specifies that the source coordinates are passed in a packed format and/or that the result coordinates should be returned in a packed format depending on what you pass to the SrcCoordYArrayPtr and DstCoordYArrayPtr parameters. If SrcCoordYArrayPtr is passed M_NULL, SrcCoordXArrayPtr is assumed to be a packed set of X- and Y-coordinates. If DstCoordYArrayPtr is passed M_NULL, DstCoordXArrayPtr is filled with a packed set of X- and Y-coordinates. If both SrcCoordYArrayPtr and DstCoordYArrayPtr are passed M_NULL, SrcCoordXArrayPtr is assumed to be a packed set of X- and Y-coordinates, and DstCoordXArrayPtr is filled with a packed set of X- and Y-coordinates. (summarize) Specifies that the source coordinates are passed in a packed format and/or that the result coordinates should be returned in a packed format depending on what you pass to the SrcCoordYArrayPtr and DstCoordYArrayPtr parameters. (more details...)

Combination constants for any of the possible values of the TransformType parameter.

You can add one of the following values to the above-mentioned values to set the return values of invalid points.

For specifying to return invalid points
Combination value	Description
M_NO_EXTRAPOLATED_POINTS	Specifies that if a pixel involved in the transformation is not inside the calibrated region, M_INVALID_POINT will be returned, instead of a coordinate resulting from the extrapolation. The calibrated region is defined as the image region covered by the calibration grid. This can be displayed by calling McalDraw() with M_DRAW_VALID_REGION. This value only applies to piecewise linear calibrations (M_LINEAR_INTERPOLATION); if it is set and the image has any other type of calibration, it is ignored. (summarize) Specifies that if a pixel involved in the transformation is not inside the calibrated region, M_INVALID_POINT will be returned, instead of a coordinate resulting from the extrapolation. (more details...)
M_NO_POINTS_BEHIND_CAMERA	Specifies that M_INVALID_POINT is returned when a computed point is mathematically valid but physically impossible (behind the camera). If this value does not apply to the specified transformation type, then it is ignored. (summarize) Specifies that M_INVALID_POINT is returned when a computed point is mathematically valid but physically impossible (behind the camera). (more details...)

NumPoints

Specifies the number of points in the coordinate list.

SrcCoordXArrayPtr

Specifies the address of the array of the input X-coordinates.

SrcCoordYArrayPtr

Specifies the address of the array of the input Y-coordinates.

This parameter can be set to M_NULL when TransformType is set to M_PACKED. See the description of M_PACKED for more details.

DstCoordXArrayPtr

Specifies the address of the array in which to place the output X-coordinates.

If M_NO_POINTS_BEHIND_CAMERA is used and one of the source points cannot be converted, the entry in the destination array corresponding to such point is set to M_INVALID_POINT.

DstCoordYArrayPtr

Specifies the address of the array in which to place the output Y-coordinates.

This parameter can be set to M_NULL when TransformType is set to M_PACKED. See the description of M_PACKED for more details.

If M_NO_POINTS_BEHIND_CAMERA is used and one of the source points cannot be converted, the entry in the destination array corresponding to such point is set to M_INVALID_POINT.

Compilation information

Header	Include mil.h.
Library	Use mil.lib; milcal.lib.
DLL	Requires mil.dll; milcal.dll.