116 results about "Human visual perception" patented technology

A system, method and apparatus for providing a two dimensional image that will be perceived by the human visual perception system as a three dimensional image is disclosed. The system and apparatus preferably employ a transparent rear projection screen onto which an image of the at least one object to be displayed is projected. The at least one object moves at perceptual speed and preferably has highlights, comprising specular highlights, ambient lighting, shadows and reflections, consistent with its display location so that the human visual perception system perceives the displayed image as a three dimensional one. The method preferably comprises surveying the display site to identify important light sources and objects and to gather a reflection map which are both used to create the final displayed image.

The invention provides a human visual perception simulation-based self-adaptive low-illumination image enhancement method. The method is put forwards based on characteristics of low brightness and low contrast of a low-illumination color image and through researching an automatic adjustment process of pupils and photoreceptor cells for an environment. The method includes the following steps that: the adjustment process of the pupils for light is simulated, and the total brightness level of the image is improved; and the self-adaptive adjustment and control ability of eye vision for a low-illumination environment is simulated, and a nonlinear mapping model is designed to simulate the adjustment process of rod cells and cone cells, so that a bright and dark self-adaptation function can be obtained, and a bright and dark information fusing function is determined according to illumination distribution, and global self-adaptive adjustment is performed on brightness components; and the local contrast of the enhanced brightness image will be decreased, so that local self-adaptive contrast enforcement is performed on the image through adopting an exponential function; and finally, and color restoration is performed on the enhanced image. With the human visual perception simulation-based self-adaptive low-illumination image enhancement method of the invention adopted, the brightness, local contrast and detail information of the low-illumination color image can be effectively improved, and especially, the method has obvious effects in dark area and highlight area enhancement.

An image retrieval method with improved performance in which a data image similar to a query image is retrieved by appropriately combining colour and texture features. The method for retrieving a data image similar to a query image in an image database containing a plurality of data images involves: calculating colour and texture distances between a query image and each data image in the image database; weighting the calculated colour and texture distances with predetermined weighting factors; calculating a feature distance between the query image and each data image by combining the weighted colour and texture distances by considering human's visual perception attributes; and determining the data image similar to the query image using the feature distance. According to the image retrieval method, data images similar to a query image can be retrieved based on the human visual perception mechanism by combining both colour and texture features extracted from image regions. In particular, the image region based retrieval enables much accurate retrieval of more objects and many kinds of information from a single image.

A document authentication system and method combine digital and non-electronic (or visual) authentication methodologies in an integrated, unified manner. As well as providing indicia of digital authentication, the invention generates a physical artifact that can be validated by unaided human visual perception. The present invention thus provides an opportunity to improve the level of trust in authentication of documents, while preserving the advantages of both traditional and digital authentication mechanisms.

The invention relates to a color matching method for transforming a color representation of a first set of color primaries with a plurality of first signals to a second set of color primaries with a plurality of second signals in a first domain. The color matching method of the invention is to consider the characteristics of human visual perception. Since human is more sensitive to the luminous intensity than chrominance, the color matching method of the invention is considered to match the luminous intensity. The color matching method of the invention can minimize the intensity difference by utilizing the optimality of resource distribution. An additional step of smoothing the intensity difference among color primaries at the level of color primaries is appended. It enhances the visual quality especially for the images with a gradual change in numerous levels of color. Besides, when the color is outside the gamut, we keep the information of luminance by adding extra white. According to the invention, the color matching method of handling colors outside gamut can provide a higher contrast which is especially good for displaying a color change with numerous levels, such as sunrise or sunset scenes. The color matching method further considers color interactions of each color primary regarding the configuration of surrounding color primaries. With the consideration of exploiting the perceived luminous intensity instead of physical luminous intensity, a superior color matching algorithm can be made.