Zhang´s flexible technique for the calculation of intrinsic and extrinsic parameters in the adjustment of diets in crops of Oreochromis Sp

Abstract

The calculation of the intrinsic and extrinsic parameters of digital cameras used in the cultures of Tilapias, facilitate the calibration of the cameras to obtain the real biometric measurements of the fish. The mathematical model allows to relate the measurements in pixels of the optical sensor of the cameras with the biometric measurements of the tilapia. To find the size of the red tilapia by means of recognition of digital images, the internal characteristics were determined, corresponding to the geometry and optics of the camera (intrinsic parameters). Likewise, the external characteristics of the camera were determined, corresponding to the reference position with respect to the aquarium or pond (extrinsic parameters). The objective was to find a mathematical model that would allow obtaining the biometric information of the tilapia from the digital images obtained by the camera. For this case, Zhang's calibration method was applied, using images of a plane with specific patterns, captured by the camera in different positions and orientations. With the parameters found, a mathematical model was developed to relate the real biometric measurements of the tilapia with the digitized images of the tilapia.