A system and method of using a bore scope with an attached video system, the true field of view is measured, cross hair lines are generated on the video monitor and measured for extremes of field and again bracketing the object, a ratio is formed and is used as a multiplier of the true field of view. The result is the actual dimension of the object.

A method for extracting (masking off) a desired video window, such as that which forms a scanned image of a document or a portion thereof, from a overscanned image stored in a frame buffer is disclosed herein. Specifically, this method involves first determining horizontal pixel locations for left and right edges of the document for each of a plurality of scan lines located within said scanned image. Then, histograms of the left and right edge locations are fabricated. Once this has occurred, the positions of top and bottom edges of an escribing rectangle is found. The escribing rectangle is a rectangular area, located within the frame buffer, which includes the entire document. Now, with the top and bottom edge locations known, the inventive method locates the right and left edge locations of the escribing rectangle by suitably analyzing the histogram results. Next, memory address corresponding to the first pixel location in the escribing rectangle and the vertical and horizontal size of the rectangle are determined, using all the edge locations of the escribing rectangle, and then applied as input to addressing circuitry located within the frame buffer. Once this occurs, then all (or a portion of) the pixel values stored within the frame buffer and located on and within the escribing rectangle are successively accessed and routed to an output connection as being those pixel values that form the image, or a selected portion thereof, of the document.

Apparatus, and accompanying methods for use therein, for locating edges contained within each scan line of a scanned video image and also for locating horizontal boundaries (leading and trailing edges) of a portion of a document contained within the scan line are described herein. Specifically, this apparatus first provides a background value representative of a background level in a scanned image and associated with an incoming pixel value. If the background value exceeds a first reference value, a first signal is generated. If the incoming pixel value exceeds a second reference value, a second signal is generated. Now, an edge transition is detected based upon a pre-defined logical combination of the first and second signals. If such a transition has been detected, such as a leading or trailing edge in either the incoming pixel values or in the background level, a control circuit, illustratively implemented using a programmed array logic circuit and various counters, determines if the edge transition is associated with valid leading or trailing edge, i.e. wheter the transition itself is followed by a pre-determined number of similar pixel values. If a valid leading or trailing edge is detected, then the control circuit generates appropriate signals to store the horizontal pixel address of the incoming pixel value as a leading or trailing edge. In addition, once all the leading and trailing edes have been determined for a current scan line, then the leading/trailing edge pair having the widest spacing is selected as being the designated leading and trailing edges (horizontal boundaries) of a portion of a scanned document located within the current scan line.

Detecting video phenomena, such as fire in an aircraft cargo bay, includes receiving a plurality of video images from a plurality of sources, compensating the images to provide enhanced images, extracting features from the enhanced images, and combining the features from the plurality of sources to detect the video phenomena. The plurality of sources may include cameras having a sensitivity of between 400 nm and 1000 nm and/or may include cameras having a sensitivity of between 7 and 14 micrometers. Extracting features may include determining an energy indicator for each of a subset of the plurality of frames. Detecting video phenomena may also include comparing energy indicators for each of the subset of the plurality of frames to a reference frame. The reference frame corresponds to a video frame taken when no fire is present, video frame immediately preceding each of the subset of the plurality of frames, or a video frame immediately preceding a frame that is immediately preceding each of the subset of the plurality of frames.