873 results about "Edge maps" patented technology

A system and method for processing a digital video signal corresponding to an image are provided. A plurality of independent edge detecting processes or edge detector modules detect a set of edges and at least one additional edge that is not included in the set of edges. An edge map includes data regarding all edges identified by any edge detecting process or module, and a visually perceptible artifact of the image is altered based at least in part on an evaluation of the edge map. The system and method detects and filters block artifacts and ringing or other noise from digital images, resulting in reduced image distortion.

The invention relates to a tunnel lining crack width measuring method, which comprises the follow steps of: (1) picking up crack images through a digital camera and measuring pickup distance through a laser distance measuring instrument; (2) selecting a region required to be measured on the picked images and converting selected region images into gray level images; (3) determining the threshold value of the gray level images selected in the second step, cutting binary image cutting, and obtaining a target region; (4) extracting a white region only comprising crack in the target region; (5) extracting the edge of the crack by a sub pixel method, and obtaining sub pixel level edge images; (6) circulating the pixel width of the crack by a minimum distance method; (7) circulating the actual width of the obtained crack according to the calibration proportion of the predetermined actual pixel size and the image pickup distance; and (8) storing the obtained actual width data into a crack data base. Compared with the prior art, the tunnel lining crack width measuring method has the advantages of low cost, high speed, convenience, high precision and the like.

The invention discloses a target detection and recognition method for water surface panoramic images, and belongs to the technical field of computer visual recognition. The method comprises the following steps of: firstly carrying out target detection and recognition on a panoramic image by utilizing a target detection and recognition neural network model, and obtaining a target type and an initial position of a detection box; carrying image segmentation on a target local area to obtain a plurality of superpixel blocks, and combining the superpixel blocks by adoption of a multi-threshold fusion strategy so as to obtain an adjusted target detection box; calculating an edge map of a new target local area, adjusting the target detection box according to peripheral edge points of the target detection box so as to obtain a final target detection box; and finally converting the position of the final target detection box into a target practical position. According to the method, distortion effect in panoramic images can be effectively overcome, and target positions can be correctly recognized from the panoramic images.

A method for correcting colored fringe artifacts in a region of an image around saturated pixels captured by an electronic imager associated with a color filter array, includes providing a threshold map of the image based on thresholding one or more color channels with a common or separate threshold value for each color channel; providing a first edge map by dilating the threshold map as a function of the color fringe width, producing a first dilated threshold map and subtracting the threshold map from the first dilated threshold map; and color-desaturating image pixels that correspond to the first edge map.

A method of compressing video content is disclosed and may include receiving an image frame of a video signal having multiple components, generating an edge-map for the image frame, generating a bitstream base layer for each component of the video signal, generating a first bitstream enhancement layer for each component of the video signal, and generating successive bitstream enhancement layers for each component of the video signal. As the successive bitstream enhancement layers are generated, the method of compressing video content goes from lossy to lossless.

A conversion method and apparatus with a generating of a depth map for two dimensional (2D)-to-three dimensional (3D) conversion. A depth order may be restored based on a line tracing and an edge map generated from an input image, and a stereo image may be generated using depth information.

The invention discloses an adaptive threshold edge detection algorithm based on canny. The adaptive threshold edge detection algorithm based on canny includes that firstly, carrying out Gaussian smoothing on an image, calculating the corresponding gradient, and restraining the maximum value of a gradient map; calculating to obtain a statistical histogram of the gradient map according to the detected gradient size, expressing gradient background according to the histogram information, and calculating to obtain the high threshold and low threshold of the gradient map to obtain a strong edge map and a weak edge map; using the edge point of the strong edge map as a central point to compare the edge information of the field edge point and the corresponding position in the weak edge map to connect strong and weak edges. Compared with a traditional method which sets the proportion of the strong edge as a fixed value and a method which obtains the high threshold through an inter-class maximum-variance algorithm and obtains the low threshold through multiplying the high threshold by a fixed proportion, based on keeping the low complexity and high edge quality of the original canny method, the adaptive threshold edge detection algorithm based on canny further improves the edge continuity and precision, is more suitable for extracting the main outline, and provides basis for the subsequent high-precision target detection and target division.

Aspects of depth map generation and post capture focusing and re-focusing are described. According to one embodiment, a depth map is generated. The depth map may include a mapping among relative depth values in a field of view of an image based on a difference between pixels of a first image and pixels of a second image. An edge map may also be generated by identifying edges in at least one of the first image or the second image. Using the depth map and the edge map, the relative depth values in the depth map may be smoothed using the edge map. In this manner, certain discontinuities in depth values may be smoothed within edge-bounded regions defined by the edge map. The depth map may be used for focusing and re-focusing, for example, or for object extraction, scene understanding, or gesture recognition, among other imaging processes.

The invention discloses a color image segmentation method, which comprises the following steps: processing an image to be segmented into a gray image; extracting a region profile map from the gray image by an Otsu threshold segmentation method, and determining an optimal threshold; taking the optimal threshold as a high threshold of a Canny operator, and extracting an edge map from the gray image by utilizing the Canny operator; and fusing the area profile map and the edge map, and outputting a segmentation result of a color image. The method adopts an operator threshold determining scheme combined with an adaptive strategy and an empirical value and overcomes the defect that an empirical value selecting method has application limitation; the local change intensity of a gray value is obtained through edge detection, so that over-segmentation of avoidable areas is limited; and residual edges are complemented through region segmentation, so that profiles of images after the segmentation are more clear and complete.

The invention discloses a multiple lane line detecting method based on isometric peripheral point matching. The method comprises the following steps: collecting an image of a road in front of an automobile, conducting inverse perspective projection change on the collected image of the road in front of the automobile by utilizing the interrelation of world coordinate, camera coordinate and image coordinate to obtain an aerial view of the image of the road, conducting edge detection on the aerial view, conducting pretreatment on the detected edge view, conducting local area matching on all edge points of the pretreated edge view, reserving successfully matched edge point pairs, obtaining a feature point diagram through the edge point pairs, conducting partitioning on diagram according to distribution of the feature points, extracting all feature points of one lane line I, isolating feature point areas which belong to other lane lines II, and taking the feature point areas as the candidate area of the lane line I. According to the method, the technical problems of multiple lane line detection, lane line positioning and bending, and solid lane line and dotted lane line discrimination in the conventional method can be effectively solved.

The invention discloses a method for realizing the positioning fitting of cover plate glass and a liquid crystal screen. The method comprises the following steps of: obtaining the image of the cover plate glass and the image of the liquid crystal screen, detecting characteristic points in the images, selecting one group of opposite angle marks through condition restriction, carrying out connection, carrying out refining treatment on the pixel characteristic values of each obtained characteristic point to obtain a sub pixel level coordinate value, obtaining a control parameter, and controlling the cover plate glass and the liquid crystal screen to move to finish monocular preliminary checkout; obtaining the images of one group of angular points of the cover plate glass and the images of one group of angular points of the liquid crystal screen, and detecting the edges of the images to obtain the image which is only provided with an edge line; finally, extracting straight lines from the edge image, screening lines to determine two edge straight lines of each required angular point, calculating the coordinate of each angular point, obtaining the midpoint coordinate and the slope of one diagonal line of the cover plate glass, the coordinate difference value of two midpoints and the inclined angle of two straight lines, and the midpoint coordinate and the slope of one diagonal line of the liquid crystal screen, the coordinate difference value of two midpoints and the inclined angle of two straight lines; and controlling the cover plate glass and the liquid crystal screen to move to enable the two straight lines to be in parallel and enable the midpoints to be subjected to superposition so as to finish the fitting of the cover plate glass of the touch screen and the liquid crystal screen.

An image resolution conversion method and apparatus based on a projection onto convex sets (POCS) method are provided. The image resolution conversion method comprises detecting an edge region and a direction of the edge region in an input low-resolution image frame in order to generate an edge map and edge direction information, generating a directional point spread function based on the edge map and the edge direction information, interpolating the input low-resolution image frame into a high-resolution image frame, generating a residual term based on the input low-resolution image frame, the high-resolution image frame, and the directional point spread function, and renewing the high-resolution image frame according to a result of comparing the residual term with a threshold.

A method for processing an input image to reduce halo artifacts in an electrophotographic printing system. The input image is automatically analyzed to determine an edge map image indicating light-side edge regions that include edge pixels that are adjacent to edge transitions in the input image and are on a lighter side of the edge transition. At least one edge region dilation operation to the edge map image to expand the light-side edge regions in a direction away from the edge transitions. A corrected image is formed by modifying the input pixels of the input image corresponding to the expanded light-side edge regions to determine corrected pixels having corrected pixel values. The corrected image is then printed using the electrophotographic printing system.

A preprocessing section binarizes input image data and calculates a total black pixel ratio. A feature extracting section detects connected components contained in the binarized image data and detects circumscribing bounding boxes that circumscribe these connected components, respectively. Based on sizes of the circumscribing bounding boxes detected and numbers of black pixels contained therein, predetermined connected components are removed. A determining section generates an edge map by using the residual connected components, and performs two-dimensional fast Fourier transform thereon to generate spectral data. The determining section performs two-dimensional fast Fourier transform on template images to generate spectral data. The determining section determines, based on these pieces of spectral data, whether or not a circular shape is contained in the input image data.

A method reconstructs a depth image encoded as a base layer bitstream, and a set of enhancement layer bitstreams. The base layer bitstream is decoded to produce pixels of a reconstructed base layer image corresponding to the depth image. Each enhancement layer bitstream is decoded in a low to high order to produces a reconstructed residual image. During the decoding of the enhancement layer bitstream, a context model is maintained using an edge map, and each enhancement layer bitstream is entropy decoded using the context model to determine a significance value corresponding to pixels of the reconstructed residual image and a sign bit for each significant pixel, and a pixel value of the reconstructed residual image is reconstructed according to the significance value, sign bit and an uncertainty interval. Then, the reconstructed residual images are added to the reconstructed base layer image to produce the reconstructed depth image.

The invention relates to a method and a system for extracting field image edges of plant leaves. The method comprises the following steps of: 1, smoothing and denoising a subimage in a partition area adjacent to an area containing a single leaf serving as a target image; 2, performing area-based threshold partition and gradient-based edge detection partition on the image processed by the step 1, and performing initial optimization to acquire an inner template of a target area; 3, judging whether the target area of the image processed by the step 2 is a leaf image or not, if so, executing the step 4, and otherwise, performing grayscale mapping and morphological reconstruction on the image processed by the step 1, and executing the step 2; and 4, performing operation of adhesion disconnection, false edge removal and closure on the image processed by the step 2 to obtain the edge image with a closed edge. The method and the system improve the accuracy and integrality of the extraction ofthe field image edges, which have non-uniform grayscale, of the plant leaves.

The invention belongs to the field of image acquiring and processing, and particularly relates to an image acquiring and processing method based on an FPGA (field programmable gate array) serving as a control core. The method mainly includes building an image acquiring and processing SOPC (system on programmable chip) system comprising a Nios II soft-core processor module, a CMOS (complementary metal-oxide-semiconductor transistor) image sensing controller module, an FIFO (first in first out) controller module, an SDRAM (synchronous dynamic random access memory) controller module, a Canny edge detection algorithm module and a VGA (video graphic array) controller module. Firstly, images are acquired and then cached in the FIFO controller module; secondly, image data in the FIFO controller module are transmitted to an off-chip SDRAM chip by FPGA software and are stored in the off-chip SDRAM chip; thirdly, images in a memory are processed by means of an image processing algorithm, 'ping pong operation' is realized during processing, and the processing images are stored in the SDRAM again; and finally, the acquired edge images are displayed through a VGA interface after being processed.

A method for optic disk detection in retinal images, includes: extracting a vessel tree from a retinal image; locating an optic disk in the retinal image using the vessel tree; enhancing a contrast of the optic disk; removing vessels from the contrast enhanced optic disk; detecting a boundary of the optic disk with vessels removed by generating an edge map; projecting the edge map at a plurality of angles by using a radon transform; and estimating a radius and center of the optic disk using the projections.

The invention discloses a cover defect detection method based on image processing. The method comprises steps that S1, an excircle contour radius and glue injection zone width of a standard image are acquired in a man-machine interaction mode; S2, edge detection on a to-be-detected cover image is carried out to determine an edge image; S3, edge tracking of the edge image is carried out to acquire edge points, edge fitting of the edge points is carried out to acquire a fitting circle center position and a fitting radius; in combination with the glue injection zone width of the standard image, the fitting circle center position and the fitting radius, the glue injection zone is determined; and S4, cover defect detection and identification are carried out. Through the method, properties of short time, high efficiency and good timely detection effect are realized, and the excellent detection effect is acquired in an actual production line.

A system and method of restoring an occluded background region includes detecting surfaces of a point cloud, thereby resulting in a surface map; substantially enhancing edges between detected surfaces according to a gradient map and the surface map, thereby generating an edge map; inpainting a depth image, thereby generating in an inpainted depth image; and inpainting a color image, thereby generating an inpainted color image.

A system and process for improving image quality is described. The process uses an edge map to smooth colors based on at least one of how close a pixel is to an edge and the strength of the edge.