## 1 Introduction
As a result, details of the shaped surface can be better captured at multiple angles, while the accuracy of the acquired data is higher. In the digitizing process, it is possible to change the position of the projector or camera within the space but not of both in the same process. Subsequently, the researchers of [5] developed a self-calibrating active digitizing device using a laser scanning technique employing line lasers and a single camera. A device with a projector of two laser lines and a camera was built, and the device can be freely moved within the space during the digitization process, and thus, the surface of the object can be digitized. The device uses a sequence of frames for calibration and depth measurement, during which the laser projector is moved backwards and forwards. The device records a constant point as the intersection of two laser lines at an angle of 90\({}^{\circ}\). Utilizing this technique, the authors of [6] measured the three-dimensional distance to the gastric surface in medicine by image processing of the stereo matching method. As part of the subsequent research, the authors of [7] followed up on previous work in digitizing the object using laser techniques and self-calibration. In this work, they presented a 3D dense point cloud acquisition technique based on a laser digitization technique using projection of line lasers onto planar surfaces. As the basic information for 3D data acquisition, the projected laser curves on planar surfaces are captured by a single camera at a viewing angle non-parallel to the laser beam source, where the laser beam source and the projected beam are repositioned, and the camera position is constant in the process. In particular, the description of the process and the numerical calculation required for obtaining a 3D surface model of planar objects by the laser technique can be considered as a contribution of this work. The authors of [8] presented a 3D endoscopic digitizing device using the \"active stereo\" technique. The active stereo technique can be defined as a digitizing technique using one or more structured light projectors and one or more cameras, whereby the light pattern of a mesh grid is projected onto an object, and the surface of the object is calculated based on the distribution of the light pattern on the object. The projector was composed of a laser light projector and an optical fiber transmitting the light source to a projector head located on the outside of the endoscope using a thin and flexible tube. The endoscopic device recorded an image with blurring, which had to be compensated for by an algorithm in the endoscope calibration process. In contrast to the structured light technique using the encoding of positional information within shape patterns explicitly, in the active stereovision technique, the intersection lines of the laser beams were implicitly used as reference points for the computation of the surface in space. A complex process was used to calibrate the projector by projecting the image pattern through the display, which was recorded by a separate camera, not an endoscopic camera; then, the laser pattern was projected onto the display. The projected pattern could then be aligned with the shape image on the display. In a practical validation of the device, a distance measurement error of 0.89% and an angle measurement error of 2.17% were recorded. The authors of [9] presented a method of calibration of a device for measuring the shape and size of objects for the examination of body parts in the field of medical diagnostics, a prototype 3D endoscopic device with an active stereovision technique. The proposed calibration method did not require the use of a calibration camera other than the endoscopic camera, using a device with a spherical surface shape for calibration, and at the same time, there was no need to distinguish between the distance of the calibration camera and the endoscopic camera. The authors of [10] followed up on previous work and improved the design of the prototype device.