Abstract: A visual perception threshold unit for image processing identifies a plurality of visual perception threshold levels to be associated with the pixels of a video frame, wherein the threshold levels define contrast levels above which a human eye can distinguish a pixel from among its neighboring pixels of the video frame. The present invention also includes a method of generating visual perception thresholds by analysis of the details of the video frames, estimating the parameters of the details, and defining a visual perception threshold for each detail in accordance with the estimated detail parameters. The present invention further includes a method of describing images by determining which details in the image can be distinguished by the human eye and which ones can only be detected by it.

Abstract: Methods and systems for separating a picture part of interest from an arbitrary background in real time videos are presented. The background may be a moving or still frame. The picture part of interest and background frames may be in or out of focus. One separation approach employs the difference between luminance and chrominance values of the input and background frames where changes in luminance from frame to frame are compensated for. In another approach, picture part of interest separation is based solely on spatial resolution differences between the background and the picture part of interest frames. The present invention also teaches a method and system for parameter matching of the picture part of interest and the basic picture into which the picture part of interest is embedded. The invention further teaches a method and system for embedding a separated picture part of interest into a basic picture containing text.

Abstract: A video encoding system includes a visual perception estimator, an encoder, a compression dependent threshold estimator and a filter unit. The visual perception estimator estimates a perception threshold for a pixel of a current frame of a videostream. The encoder encodes the current frame. The compression dependent threshold estimator estimates a compression dependent threshold for the pixel at least from the perception threshold and information from the encoder. The filter unit filters the pixel at least according to the compression dependent threshold.

Abstract: A visual lossless encoder for processing a video frame prior to compression by a video encoder includes a threshold unit, a filter unit, an association unit and an altering unit. The threshold unit identifies a plurality of visual perception threshold levels to be associated with the pixels of the video frame, wherein the threshold levels define contrast levels above which a human eye can distinguish a pixel from among its neighboring pixels of the frame. The filter unit divides the video frame into portions having different detail dimensions. The association unit utilizes the threshold levels and the detail dimensions to associate the pixels of the video frame into subclasses. Each subclass includes pixels related to the same detail and which generally cannot be distinguished from each other. The altering unit alters the intensity of each pixel of the video frame according to its subclass.