Showing papers on "Image gradient published in 1984"

System and method for transforming and filtering a video image

Abstract: A video transformation and filtering system generates for each source image data point a plurality of target image addresses indicating a displacement between a point at which the source image data point maps into the target image and each data point of the target image which is affected by the source image data point. By providing either sequentially or in parallel a separate processing for each target image data point that is affected by a current source image data point values for all of the target image data points can be generated from a single pass of the source image data points. By effectively providing the filtering in the domain of the target image instead of the source image a single filter function with a fixed number of points in the target image domain can be used to attain low pass filtering of the resulting target image irrespective of the degree of size compression of the video image.

Apparatus and method for enhancement of video images

Abstract: An apparatus and method for producing digital video images provides for obtaining a first image (42) and a second image (44), and subtracting the first from the second to obtain a difference image (46). The intensity of the difference image is increased relative to the first image (48). The enhanced difference image is added to the first image (50). The result is an image which emphasizes changes between the first and second images, while preserving enough common background to provide a frame of reference from which to view the changes.

High-Speed Manipulation of the Color Chromaticity of Digital Images

Abstract: Using Peano curves and digital techniques, this aid to the interpretation of complex images enhances color chromaticity while reducing processing time.

Image sensor system

Abstract: The image sensor system includes an image sensing means for producing an image signal by sensing a field of view. This image signal is sent to a means which reproduces an image of the field. An optical projection means forms an optical image of this image of the field reproduced by the image reproducing means, at the same size as and in registration with the field itself and illuminating the field. Thereby contrast of the image of the field is improved by an optical feedback process.

Application of Image Processing Techniques to Marine Fisheries

Abstract: The problem of subdividing an ocean area into coherent subregions is investigated. The subdivision is based on the image processing technique of region segmentation. The region segmentation applied is the Global-Local Edge Coincidence algorithm (GLEC). GLEC requires the application of several image processing operations including clustering, gradient analysis, region labelling, and others. The data bases selected for this analysis consist of the Nimbus-7 Satellite CZCS sensor derived phytoplankton concentration and temperature images. The interpretation of the resulting ocean area subdivision is also discussed.

System for transforming and filtering a video image

Abstract: A video transformation and filtering system generates for each source image data point a plurality of target image addresses indicating a displacement between a point at which the source image data point maps into the target image and each data point of the target image which is affected by the source image data point. By providing either sequentially or in parallel a separate processing for each target image data point that is affected by a current source image data point values for all of the target image data points can be generated from a single pass of the source image data points. By effectively providing the filtering in the domain of the target image instead of the source image a single filterfunction with a fixed number of points in the target image domain can be used to attain low pass filtering of the resulting target image irrespective of the degree of size compression of the video image.

High-order tensor product approximation for two- and three-dimensional image blocks with application to multiresolution image representation

Abstract: Tensor product approximation methods are described for 2D and 3D image blocks. These methods will have application in multiresolution image representation and in the associated algorithms. A proper blending of these methods would be useful for hierarchical representation of images and in the compression of images to a desired resolution.

Visual identification using elliptic features

Abstract: A visual identification system for planar shapes based on the elliptic features is presented. The edge detection results in a list of run codes, which contain the edge information. The connectivity analysis then obtains the edge points in consecutive order. Three sets of invariants are computed from the elliptic Fourier features and used for recognition. Location and orientation are also computed from elliptic Fourier coefficients.

Density Pseudocolor Encoding By Holographic Techniques With Three Primary Colors

Abstract: A new optical method to generate a family of color-coded images using holographic techniques is presented. This method involves the introduction of three primary colors. Thus, this technique overcomes an important limitation of previous holographic techniques. An image hologram of a black-and-white transparency is first registered. This hologram is put in contact with a beam splitter, and the sandwich is illuminated by three partially coherent waves. One wave produces a positive image, a second wave pro-duces an image with reversed contrast, the negative, and the third image corresponds to the product of the positive and the negative. Coding these waves in three primary colors and adding them at the final image plane results in a color-coded image. The principle of the method, theory, and some experimental color results are presented.