Abstract: A refrigerated device having a cooled enclosure and an evaporator through which refrigerant is circulated. An air temperature sensor adapted to generate an air temperature signal indicative of air temperature within the enclosure is provided. A refrigerant temperature sensor adapted to generate a refrigerant temperature signal indicative of refrigerant temperature is provided. A programmable controller adapted to compare the air temperature signal and the refrigerant temperature signal to calculate a difference between the air temperature and the refrigerant temperature is provided. The controller initiates a defrost routine for removing condensate from the evaporator if the difference between the air temperature and the refrigerant temperature is greater or equal to a defrost threshold. Also disclosed are methods for defrosting a refrigerated device and for detecting condensate accumulation.

Abstract: An image processing system encodes a natural image into a segmented or mosaic image having well-defined edges and a residual image. The segmented image is encoded using a lossless encoding technique while the residual image is encoded using a lossy technique. This encoded image may be recorded on a video tape such that the segmented image may be recovered in picture-in-shuttle modes such as fast forward and fast rewind. In addition, the recorded image may be decoded and reencoded through several generational levels without experiencing significant degradation in perceived image quality. The segmented image is produced by an encoder which employs a multi-scale edge finder that is able to resolve transitions occurring over two, four and eight pixels into an edge located between two pixels.

Abstract: A video signal processor controls aperture correction of the video signal by detecting the occurrence of particular colors in the image produced by the video signal. The particular color, for example, fleshtone, is detected as a ratio of the amplitude of an in-phase color signal and the magnitude of its corresponding quadrature phase color signal. This defines a range of color phases which are classified as the particular color, regardless of their saturation. The detected color is converted into a control signal which changes the amplitude of the aperture correction signal. In one embodiment the control signal has a value of zero if the detected color is within the range of color phases and a value of one otherwise. This control signal is used as a multiplier for the aperture correction signal. In another embodiment, a second range of colors is defined around the defined range.

Abstract: An edge finder for an image processing system locates edges in a digitized image over several different ranges of pixel values and assigns, to each pixel value an edge characteristic value which represents a minimum edge value for the pixel in the image. The exemplary edge finder that is able to resolve transitions occurring between two pixels or over groups of four or eight pixels to determine whether an edge should be defined between the original two pixels. The edge finder simultaneously examines four edges in two dimensions to determine the edgeness value for each pixel in the digitized image.

Abstract: A pressure control test apparatus which provides a simulation of various ambient operating conditions to a test unit such as an internal combustion engine and the like, the apparatus including a plenum chamber having air therein under closely controlled temperature and pressure limits, an intake blower for supplying air into said plenum chamber and an intake valve operable to modulate flow of air between the intake blower and the plenum chamber, an exhaust blower operative to exhaust gas from the plenum chamber and an exhaust valve positioned between the exhaust blower and the plenum chamber operable to modulate flow of gas therebetween, the plenum chamber further defining an inlet and an outlet, the inlet being connected to an intake conduit to supply air to the air intake of a test unit and the outlet communicating with an exhaust conduit for receiving exhausted gas from the test unit and returning same to the plenum chamber, also further including an exhaust gas cooler positioned within the exhaust conduit