Abstract:
Method, device, and non-transitory computer-readable medium detecting a gathering of objects based on stereo vision are disclosed, and the method comprises steps of obtaining current and prior images and a corresponding depth map; extracting foreground pixels corresponding to detection objects from the current and prior images, and projecting the foreground pixels onto a ground surface to acquire a foreground projection image including foreground projection blocks; conducting, based on image feature differences of the foreground pixels between the current and prior images, projection onto the ground surface to acquire moving foreground projection blocks; utilizing the moving foreground projection blocks to erode the foreground projection blocks to obtain still foreground projection blocks; and determining, based on the still foreground projection blocks, whether the gathering of objects exists.
Abstract:
A method and an apparatus for detecting persons are disclosed. The method includes initially detecting the persons in a height-top-view; dividing the height-top-view into one or more regions, and estimating crowd density in each region; determining, based on the crowd density, visible regions of the initially detected persons in each of the regions; for each of the initially detected persons, extracting a first gradient feature and a second gradient feature of the person from the height-top-view, and a grayscale image or a color image corresponding to the height-top-view, respectively; for each of the initially detected persons, determining, based on the extracted first gradient feature and second gradient feature, using a previously constructed classifier corresponding to the determined visible region of the person, a confidence level of the initially detected person; and correcting, based on the confidence level, a detection result of the initially detected persons.
Abstract:
Method, device, and non-transitory computer-readable medium detecting a gathering of objects based on stereo vision are disclosed, and the method comprises steps of obtaining current and prior images and a corresponding depth map; extracting foreground pixels corresponding to detection objects from the current and prior images, and projecting the foreground pixels onto a ground surface to acquire a foreground projection image including foreground projection blocks; conducting, based on image feature differences of the foreground pixels between the current and prior images, projection onto the ground surface to acquire moving foreground projection blocks; utilizing the moving foreground projection blocks to erode the foreground projection blocks to obtain still foreground projection blocks; and determining, based on the still foreground projection blocks, whether the gathering of objects exists.
Abstract:
A method and a system for updating a background model based on depth are disclosed. The method includes receiving, in response to the occurrence of a predetermined background updating condition, one or more depth images captured after a time when the predetermined background updating condition occurs; obtaining, based on an original background model, foreground images in the one or more captured depth images, which are newly added compared with a depth image at the time when the predetermined background updating condition occurs; for each of foreground pixels in each of the newly added foreground images, comparing a current depth value with a previous depth value before the time when the predetermined background updating condition occurs; and updating, when the current depth value is greater than the previous depth value, the original background model as the updated background model by using the foreground pixel in the newly added foreground image.
Abstract:
A method and an apparatus for separating objects are disclosed. The method includes obtaining a depth image including a plurality of objects; obtaining a two-dimensional image including the objects; performing pixel-clustering using depth values of pixels in the depth image and pixel values of pixels in the two-dimensional image to obtain a plurality of sub-regions; performing region-clustering for the sub-regions to obtain a clustering result as an object separation result; and outputting the object separation result.
Abstract:
A method and an apparatus for separating objects are disclosed. The method includes obtaining a depth image including a plurality of objects; obtaining a two-dimensional image including the objects; performing pixel-clustering using depth values of pixels in the depth image and pixel values of pixels in the two-dimensional image to obtain a plurality of sub-regions; performing region-clustering for the sub-regions to obtain a clustering result as an object separation result; and outputting the object separation result.
Abstract:
A method and an apparatus for detecting persons are disclosed. The method includes initially detecting the persons in a height-top-view; dividing the height-top-view into one or more regions, and estimating crowd density in each region; determining, based on the crowd density, visible regions of the initially detected persons in each of the regions; for each of the initially detected persons, extracting a first gradient feature and a second gradient feature of the person from the height-top-view, and a grayscale image or a color image corresponding to the height-top-view, respectively; for each of the initially detected persons, determining, based on the extracted first gradient feature and second gradient feature, using a previously constructed classifier corresponding to the determined visible region of the person, a confidence level of the initially detected person; and correcting, based on the confidence level, a detection result of the initially detected persons.
Abstract:
A method and a system for updating a background model based on depth are disclosed. The method includes receiving, in response to the occurrence of a predetermined background updating condition, one or more depth images captured after a time when the predetermined background updating condition occurs; obtaining, based on an original background model, foreground images in the one or more captured depth images, which are newly added compared with a depth image at the time when the predetermined background updating condition occurs; for each of foreground pixels in each of the newly added foreground images, comparing a current depth value with a previous depth value before the time when the predetermined background updating condition occurs; and updating, when the current depth value is greater than the previous depth value, the original background model as the updated background model by using the foreground pixel in the newly added foreground image.