The specification provides a depth imaging method and device and a computer-readable storage medium. The method includes: controlling an emission module comprising a light emitting device to emit at least two speckle patterns that change temporally to a target object; controlling an acquisition module comprising a light sensor to acquire reflected speckle patterns of the at least two speckle patterns reflected by the target object; and performing spatial-temporal stereo matching by using the reflected speckle patterns and the at least two reference speckle patterns, to calculate offsets of pixel points between speckles of the at least two reference speckle patterns and speckles of the reflected speckle patterns, and calculating depth values of the pixel points according to the offsets.

A 3D measurement system includes: a projection module, configured to project an image to a target object, where the image includes at least three frames of phase shift fringe images and one frame of speckle image; an acquisition module, configured to acquire the phase shift fringe images and the speckle image; and a processor, configured to: calculate a relative phase of each pixel of the phase shift fringe images, match the speckle image with a pre-stored reference image, to obtain a first depth value of the pixel, perform phase unwrapping on the relative phase of the pixel according to the first depth value to determine an absolute phase of the pixel, and determine a second depth value of the pixel based on the absolute phase. An accurate depth value is calculated according to the absolute phase, thereby improving measurement accuracy.

A non-transitory computer-readable storage medium stores a projection adjustment program which, when executed by a processor, causes a computer to execute a process relating to adjustment of projection operations of projection devices configured to perform position measurement and projection on a target object in a projection system including the projection devices. The process includes: causing a first projection device to project invisible measurement light onto the target object; causing a second projection device to receive reflection light reflected from the target object; judging a connection relationship of a projection range of the first projection device on the basis of the received reflection light; executing a process of the judging of the connection relationship on all processing target projection devices; and generating projection position information indicating a connection relationship between projection ranges of the respective projection devices and displaying the projection position information on a display unit.

A calibration method for fringe projection systems based on plane mirrors. Firstly, two mirrors are placed behind the tested object. Through the reflection of mirrors, the camera can image the measured object from the front and other two perspectives, so as to obtain 360-degree two-dimensional information of the measured object. The projector projects three sets of phase-shifting fringe patterns with frequencies of 1, 8, and 64. The camera captures the fringe image to obtain an absolute phase map with a frequency of 64 by using the phase-shifting method and the temporal phase unwrapping algorithm. By using the calibration parameters between the projector and the camera, the absolute phase map can be converted into three-dimensional information of the measured object. Then, the mirror calibration is realized by capturing a set of 3D feature point pairs, so that the 3D information from different perspectives is transformed into a unified world coordinate system. The calibration method does not need to artificially fix the feature pattern on plane mirrors, only needs to capture a set of 3D feature point pairs by the camera to directly realize the mirror calibration that it avoids the loss of measurement accuracy and realizes high-precision panoramic three-dimensional measurement.

3D metrology techniques are disclosed for determining a changing topography of a substrate processed in an additive manufacturing system. Techniques include fringe scanning, simultaneous fringe projections, interferometry, and x-ray imaging. The techniques can be applied to 3D printing systems to enable rapid topographical measurements of a 3D printer powder bed, or other rapidly moving, nearly continuous surface to be tested. The techniques act in parallel to the system being measured to provide information about system operation and the topography of the product being processed. A tool is provided for achieving higher precision, increasing throughput, and reducing the cost of operation through early detection and diagnosis of operating problems and printing defects. These techniques work well with any powder bed 3D printing system, providing real-time metrology of the powder bed, the most recently printed layer, or both without reducing throughput.

A shape measuring apparatus includes a stage, a light projecting portion, a light receiving portion, and a rotation unit. The rotation unit is attached to an end of the stage. The rotation unit rotates the measurement subject about a rotation axis that vertically intersects while holding the measurement subject. In a state where the measurement subject is at a predetermined rotation angular position, the pattern light is emitted from the light projecting portion to the measurement subject a plurality of times while being phase-shifted. At this time, the light receiving portion captures an image of the measurement subject. Three-dimensional shape data is generated on the basis of a plurality of pieces of image data obtained by imaging.

A three-dimensional shape measuring apparatus includes a fixer that fixes an illuminator and a photoreceptor to produce a measurement area to be illuminated with measuring light above a stage and to incline their optical axes with respect to a placement surface of the stage in an orientation in which the illuminator and the photoreceptor face the measurement area obliquely downward; a point cloud data generator that generates point cloud data as a set of points including three-dimensional position information representing a three-dimensional shape of a measurement object placed on the stage based on light-reception signals provided by the photoreceptor; a top view map image generator that generates a top view map image representing a plan view of the measurement object as viewed downward from a position right above the measurement object based on the point cloud data; and a display that displays the top view map image.

A method for controlling an electronic instrument including a projection section that projects an image via a projection lens and an imaging section that performs imaging via an imaging lens includes causing a first storage to store first characteristic data representing the characteristics of the projection lens, second characteristic data representing the characteristics of the imaging lens, and arrangement data representing the arrangement of the projection lens and the imaging lens and then causing the projection section to project a pattern image on an object via the projection lens, causing the imaging section to capture an image of the pattern image on the object via the imaging lens to generate captured image data, and updating the arrangement data based on the captured image data, the first characteristic data, and the second characteristic data without updating the first characteristic data and the second characteristic data.

A three-dimensional shape measuring apparatus includes: a single projector device that projects a first light pattern whose luminance changes at a first cycle and a second light pattern whose luminance changes at a second cycle that is longer than the first cycle on a measured object; an image capture device that acquire an image of the measured object on which the first or second light pattern is projected; and an image processing device that processes the image acquired by the image capture device. The image processing device includes a relative phase value calculation unit that calculates a relative phase value on each part of the measured object based on a luminance value of an image of the measured object on which the first light pattern is projected, an absolute phase value calculation unit that calculates an absolute phase value on each part of the measured object based on a luminance value and the relative phase value of an image of the measured object on which the second light pattern is projected, and a three-dimensional coordinate calculation unit that calculates three-dimensional coordinates at each part of the measured object based on the absolute phase value.

A three-dimensional shape measuring apparatus includes: a single projector device that projects a first light pattern whose luminance changes at a first cycle and a second light pattern whose luminance changes at a second cycle that is longer than the first cycle on a measured object; an image capture device that acquire an image of the measured object on which the first or second light pattern is projected; and an image processing device that processes the image acquired by the image capture device. The image processing device includes a relative phase value calculation unit that calculates a relative phase value on each part of the measured object based on a luminance value of an image of the measured object on which the first light pattern is projected, an absolute phase value calculation unit that calculates an absolute phase value on each part of the measured object based on a luminance value and the relative phase value of an image of the measured object on which the second light pattern is projected, and a three-dimensional coordinate calculation unit that calculates three-dimensional coordinates at each part of the measured object based on the absolute phase value.