Object three-dimensional information acquisition method based on digital close range photography

Abstract

The invention discloses an object three-dimensional information acquisition method based on digital close range photography. According to the method, some code mark points are placed in any scene, and calibration is performed on internal parameters of a camera through a self-calibration algorithm; when three-dimensional reconstruction is performed on an object, the digital camera is held in hand to shoot the object from different angles to obtain two pictures, then an SIFI key point detection method is used for detecting coordinate information of key points on the object, and calibration of external parameters of the camera is completed; a light stream detection method is used for detecting matching points, corresponding to pixel points on one picture, on the other picture, and a double-view reconstruction method is used for obtaining three-dimensional information of the object according to the matching points, the internal parameters of the camera and the external parameters of the camera. Additional equipment such as a laser and a projector is needed in a traditional three-dimensional measurement method for assisting completion of three-dimensional reconstruction, while in the object three-dimensional information acquisition method, the picture light stream detection method instead of the equipment is adopted to obtain information of the matching points on the object, therefore, an active three-dimensional reconstruction mode is achieved, hardware cost is reduced, and the method is convenient to realize.

Description

Technical field [0001] The invention belongs to the technical field of object three-dimensional information measurement, and more specifically, relates to an object three-dimensional information acquisition method based on digital close-range photography. Background technique [0002] In recent years, with the development of China's manufacturing industry, especially the rapid development of advanced manufacturing technology centered on digital manufacturing, large and complex workpieces have been widely used in wind power, automobiles, ships, aircraft, and military industries. How to measure these large and complex workpieces and obtain their three-dimensional information is a problem that these industries need to solve. [0003] At present, many industries use laser scanning, three-coordinate measuring machines, and articulated arms to perform three-dimensional measurement of small and medium-sized workpieces less than 1 meter in length, which can basically meet the inspection re...

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Problems solved by technology

[0004] Theodolite measurement system is the earliest and most widely used system in the field of large-scale workpiece measurement; its advantage is that the measurement range can reach 2 meters to tens of meters, and it adopts optical and non-contact measurement methods, and the measurement accuracy can be achieved within 20 meters. It can reach 10μm / m, but the disadvantage is that it generally uses manual aiming at the target for point-by-point measurement, which is slow and the degree of automation is not high.

When measuring large workpieces, these measuring devices have cumbersome station shifting problems, and can only measure the three-dimensional coordinates of the key points of the workpiece, and cannot perform full-scale inspection;

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