Abstract: The present invention discloses an error correction method for an FPP system. Implementation steps are as follows: first, collecting deformed fringes affected by an object using a camera; then, calculating the fringe modulation I? by using the collected images, and normalizing the modulation; setting a segmentation threshold T, and for all pixels of which modulation I?<T, dividing them into several categories and pixels within each category having close I? values; for all pixels in each category, acquiring multiple groups of N intensity values, and averaging these groups of intensity values to obtain a set of averaged intensity value curves; and finally, replacing the corresponding N intensity values of all the pixels in the category with the set of averaged intensity values, to complete image correction.

Abstract: The present invention discloses an error correction method for an FPP system. Implementation steps are as follows: first, collecting deformed fringes affected by an object using a camera; then, calculating the fringe modulation I? by using the collected images, and normalizing the modulation; setting a segmentation threshold T, and for all pixels of which modulation I?<T, dividing them into several categories and pixels within each category having close I? values; for all pixels in each category, acquiring multiple groups of N intensity values, and averaging these groups of intensity values to obtain a set of averaged intensity value curves; and finally, replacing the corresponding N intensity values of all the pixels in the category with the set of averaged intensity values, to complete image correction.

Abstract: A new three-dimensional measurement method based on wavelet transform to solve the phase distribution of a fringe pattern accurately and obtain three-dimensional profile information of a measured object from phase distribution. The method includes: projecting a monochrome sinusoidal fringe pattern onto the object; performing wavelet transform for the deformed fringe pattern acquired with CCD line by line, solving the relative phase distribution by detecting the wavelet ridge line, recording the wavelet transform scale factors at the line, and creating a quality map; dividing the relative phase distribution into two parts according to the map, and performing direct-phase unwrapping for the part with better reliability using a scan line based algorithm, and unwrapping the part with lower reliability using a flood algorithm under the guide of the quality map, to obtain the absolute phase distribution of the fringe pattern; obtaining the three dimensional information using a phase-height conversion.

Abstract: A 3D face recognition method based on intermediate frequency information in a geometric image as follows: (1) preprocessing a library and test models of 3D faces, including 3D face area cutting, smoothing processing and point cloud thinning, and discarding the lower portion of the face; (2) mapping the remainder of the face to a 2D grid using grid parameters, and performing linear interpolation on the 3D coordinates of the grid top to acquire the 3D coordinate attributes and generating a geometric image of a 3D face model; (3) performing multi-scale filtering with a multi-scale Haar wavelet filter to extract horizontal, vertical, and diagonal intermediate frequency information image images as invariable facial features; (4) calculating the similarity between the test model and the library set model with a wavelet domain structuring similarity algorithm; and (5) judging the test and library set model models with the maximum similarity belong to the same person.

Abstract: A 3D face recognition method based on intermediate frequency information in a geometric image as follows: (1) preprocessing a library and test models of 3D faces, including 3D face area cutting, smoothing processing and point cloud thinning, and discarding the lower portion of the face; (2) mapping the remainder of the face to a 2D grid using grid parameters, and performing linear interpolation on the 3D coordinates of the grid top to acquire the 3D coordinate attributes and generating a geometric image of a 3D face model; (3) performing multi-scale filtering with a multi-scale Haar wavelet filter to extract horizontal, vertical, and diagonal intermediate frequency information image images as invariable facial features; (4) calculating the similarity between the test model and the library set model with a wavelet domain structuring similarity algorithm; and (5) judging the test and library set model models with the maximum similarity belong to the same person.

Abstract: A new three-dimensional measurement method based on wavelet transform to solve the phase distribution of a fringe pattern accurately and obtain three-dimensional profile information of a measured object from phase distribution. The method includes: projecting a monochrome sinusoidal fringe pattern onto the object; performing wavelet transform for the deformed fringe pattern acquired with CCD line by line, solving the relative phase distribution by detecting the wavelet ridge line, recording the wavelet transform scale factors at the line, and creating a quality map; dividing the relative phase distribution into two parts according to the map, and performing direct-phase unwrapping for the part with better reliability using a scan line based algorithm, and unwrapping the part with lower reliability using a flood algorithm under the guide of the quality map, to obtain the absolute phase distribution of the fringe pattern; obtaining the three dimensional information using a phase-height conversion.