McalFixture

This function allows you to move the relative coordinate system to a location (position and angle) that is at a fixed offset from an object that you want to analyze. Alternatively, this function can write the values required for the move to the specified 3D transformation matrix object. To specify the location, you must pass the calculated reference location for the object and, optionally, a preestablished offset to apply to this reference location. To pass the preestablished offset, you must pass a fixturing offset object that contains the information. Use a separate call to this function to set up the fixturing offset object.

When moving the relative coordinate system (M_MOVE_RELATIVE), you can specify the reference location of the object in one of two ways, based upon some previous analysis. You can have McalFixture() use, for example, the position and angle of a model occurrence from a specified MIL Pattern Matching or Model Finder result buffer. Alternatively, you can explicitly specify a location with respect to the relative coordinate system of the MIL object passed to CalOrLocSourceId; internally, McalFixture() converts this location so that it is with respect to the absolute coordinate system, and then uses the calculated location to place the new relative coordinate system.

Note that if you know the new position and angle for the relative coordinate system in the absolute coordinate system, use McalSetCoordinateSystem() or McalRelativeOrigin() to move it explicitly. Alternatively, you can specify the default uniform camera calibration context (M_DEFAULT_UNIFORM_CALIBRATION) as the coordinate system in which the location is expressed (CalOrLocSourceId). This camera calibration context's relative coordinate system is always aligned with its absolute coordinate system (no angle, no offset, no scale). Therefore, the specified location is consequently interpreted as being relative to the absolute coordinate system.

When setting up the fixturing offset object (M_LEARN_OFFSET), McalFixture() learns the offset between a specified location and the relative coordinate system. You can specify the location using the same techniques as those available when moving the relative coordinate system. In addition, you can set it to the reference location of a specified model in its original model source image. The function then saves the offset between the location and its relative coordinate system, in the specified fixturing offset object. Typically, you have obtained the location from a training image, whereby the location is a typical reference location and the relative coordinate system is at a required offset from this location.

McalFixture() assumes that the reference location and preestablished offset use the same absolute coordinate system as the image/calibrated context in which to save the new relative coordinate system, even if their mapping to the pixel coordinate system is different.

For more information on fixturing, see Chapter 27: Fixturing in MIL.

If you adjust the relative coordinate system of a calibrated image associated with an M_VECTOR_AND_RASTER ROI, the raster information will be discarded, causing the ROI to become an M_VECTOR ROI. See MbufSetRegion() for more information.