# Walsh, Hough, or Hadamard transform

## Subclass of:

## 382 - Image analysis

## 382276000 - IMAGE TRANSFORMATION OR PREPROCESSING

### Patent class list (only not empty are listed)

#### Deeper subclasses:

Class / Patent application number | Description | Number of patent applications / Date published |
---|---|---|

382281000 | Walsh, Hough, or Hadamard transform | 10 |

20090123087 | DATA TRANSFORM APPARATUS AND CONTROL METHOD THEREOF - A data transform apparatus transforms four integer data D | 05-14-2009 |

20090324131 | SYSTEM AND METHOD FOR VIDEO BASED SCENE ANALYSIS - A method comprises searching in a video stream a first frame and a second frame that each has enough point correspondence with a image model, wherein the first frame is the nearest previous frame prior to a third frame, and the second frame is the nearest subsequent frame to follow the third frame. The method further comprises calculating an interpolation between a first mapping matrix of the first frame and a second mapping matrix of the second frame to obtain a third mapping matrix of the third frame that has insufficient point correspondence with the image model. | 12-31-2009 |

20080232713 | Image Matching Method, Image Matching Apparatus, and Program - To provide an image matching method, an image matching apparatus, and a program able to perform a matching images at a high accuracy. A Hough transform unit | 09-25-2008 |

20120070101 | ESTIMATING 3D STRUCTURE FROM A 2D IMAGE - A method for estimating three-dimensional structure from a two-dimensional image ( | 03-22-2012 |

20090169130 | ACCELERATING THE HOUGH TRANSFORM - The present disclosure describes a method and apparatus for accelerating computation of a Hough transform of a plurality of digital images of known width and height dimensions. The method includes determining a plurality of Hough values for each pixel location based on the width and height dimensions. The method further includes generating a lookup table comprising an array of Hough values corresponding to one or more Hough parameters of at least one geometric shape in at least one digital image. Each element in the array of Hough values may be based on a value of one or more Hough parameters and at least one of a height value or a width value. The method may include receiving a plurality of digital images having known width and height dimensions. The method may further include selecting, for at least one nonzero pixel of at least one of the plurality of digital images, the Hough values from the lookup table. Of course, many alternatives, variations and modifications are possible without departing from this embodiment. | 07-02-2009 |

20100215287 | METHODS AND DEVICES FOR DETECTING CHANGES IN BACKGROUND OF IMAGES USING MULTIPLE BINARY IMAGES THEREOF AND HOUGH TRANSFORMATION - The invention relates to a device and method for detecting changes in background of successive images. More particularly, the invention relates to a device and method for detecting changes in background of successive images by obtaining vertically accumulated values and horizontally accumulated values from multiple binary images of previous image and current image, obtaining pairs of rows and pairs of columns based on the vertically accumulated values and horizontally accumulated values, and transforming pairs of rows and pairs of columns using Hough transformation. | 08-26-2010 |

20140193096 | LINE SEGMENT AND ARC DETECTION APPARATUS - An apparatus and method to detect a line segment or arc using Hough transform. A Hough transform unit performs contour extraction on brightness image data to generate contour image data, with pixels having a pixel value of 0 to 255, performs the Hough transform on points in the contour image data, and counts additional values represented by pixel values of points in the contour image data in a Hough table. The Hough transform unit performs contour extraction on first to third component data to generate first to third contour data with pixels having a pixel value of 0 to 255, performs the Hough transform on points in the first to third contour data, and counts additional values represented by pixel values of points in the first to third contour data in the Hough table. The detection unit comprehensively evaluates the counts to detect a line segment or arc. | 07-10-2014 |

20090245687 | IMAGE PROCESSING METHOD AND APPARATUS FOR DETECTING LINES OF IMAGES AND START AND END POINTS OF LINES - Disclosed herein is an image processing method and apparatus for detecting the lines of images and the start and end points of the lines. The image processing apparatus includes an edge creation unit, a Hough transform unit, and an effective parameter detection unit. The edge creation unit creates an edge image using external image data input from the outside. The Hough transform unit performs a Hough transform on information about the pixel coordinates of the edge image created by the edge creation unit. The effective parameter detection unit detects the lines of the edge image by checking effective line parameters using the results of the Hough transform. The image processing apparatus may further include an edge list for storing coordinates of effective pixels constituting the edge image and a line parameter list for storing the effective line parameters. | 10-01-2009 |

20100104215 | DATA TRANSFORM APPARATUS AND CONTROL METHOD THEREOF - This invention provides a lossless 4-point Hadamard transform circuit which can minimize the number of times of addition/subtraction calculations, and reduce the number of times of round processing required to convert data including a fractional part into an integer. To this end, a DC coefficient generating unit summates four input data, and shifts the summation result 1 bit to the right to halve the summation result and to round the halved result by truncating a fractional part of the result. This 1-bit shift right result is output as a DC coefficient. An intermediate data generating unit generates, as intermediate value, a difference value between one input data of the four input data and the DC coefficient obtained by the DC coefficient generating unit. An AC coefficient generating unit generates three AC coefficients by adding the intermediate data generated by the intermediate data generating unit to other three input data. | 04-29-2010 |

20090232414 | Identifying patterns in data - An image feature within image data may be identified and located from the maximum values in a Hough voting table. The Hough voting table may be generated by converting edge pixels identified with an image data into an array. The array may be read in row order with theta on the outside loop and rho on the inside loop. In some embodiments, the storage requirements for the Hough voting table may be reduced. | 09-17-2009 |