Targets, fixtures, and workflows for calibrating an endoscopic camera

A calibration assembly for use with a stereoscopic endoscope imaging system having a field of view, the assembly comprising:

• an interface configured for constraining engagement with the endoscopic imaging system;
• a target coupled with the interface so as to be within the field of view and configurable to a relative spatial arrangement between the imaging system and the target;
• and
• a processor coupled with the imaging system and configured to determine one or more metrics for the imaging system, wherein the one or more metrics indicate whether a predetermined Focus Function focal position difference is exceeded, whether a predetermined Focus Function peak value difference is exceeded, whether a predetermined alignment shift value is exceeded, or whether an illumination level falls below a predetermined illumination level.

A method for calibrating an endoscopic imaging system having a field of view, the method using a calibration fixture having an interface for constraining engagement with the endoscopic imaging system and a target coupled with the interface so as to be within the field of view and reconfigurable between a plurality of relative spatial arrangements between the imaging system and the target, the method comprising:

• establishing a first relative spatial arrangement between the target and the imaging system with the calibration fixture;
• imaging the target with the imaging system from the first relative spatial arrangement, the target including a plurality of markers that include calibration features that include identification features, the calibration features having known target relative locations;
• establishing a second relative spatial arrangement between the target and the imaging system with the calibration fixture;
• imaging the target with the imaging system from the second relative spatial arrangement;
• processing said images to generate data from the calibration features by identifying at least some of the markers using the identification features;
• and
• calibrating the endoscopic imaging system with the generated data.

A method for calibrating an endoscopic imaging system having a field of view, the method using a calibration fixture having an interface for constraining engagement with the endoscopic imaging system and a target coupled with the interface so as to be within the field of view and reconfigurable between a plurality of relative spatial arrangements between the imaging system and the target, the method comprising:

• establishing a first relative spatial arrangement between the target and the imaging system with the calibration fixture;
• imaging the target with the imaging system from the first relative spatial arrangement, the target including a plurality of features defining a plurality of local patterns, the plurality of features having known target relative locations;
• establishing a second relative spatial arrangement between the target and the imaging system with the calibration fixture;
• imaging the target with the imaging system from the second relative spatial arrangement;
• processing said images to generate data that includes correspondences between image features and a plurality of target features by:
• detecting a plurality of the features;
• and
• locating a plurality of the local patterns by processing the detected features.