Abstract: A transmission method for a communication device that transmits signals including combined plural categories of data, and transmission format combination indicators representing data traffic of the data in each category and category combination is provided with the steps of: predicting data traffic of predetermined categories of data; selecting, among the transmission format combination indicator sets, transmission formats based on the predicted data traffic; searching, among the selected transmission format combination indicators, for transmission format combination indicators that match with transmission data; and transmitting them. Consequently, the time for searching for the transmission format combination indicators can be shortened, and by transmitting data and its transmission format combination indicators without fail, transmission quality can be improved.

Abstract: An inter-vehicle distance detecting device displays the images of preceding vehicles, sets a tracking window surrounding one of the images and tracks it, calculates the distance from the driving vehicle to the preceding vehicle, and sets a plurality of shadow windows which are not displayed and which are different from the tracking window, at predetermined positions in the image taken by one of top and bottom image sensors. Distances from the driving vehicle to objects caught by the respective shadow windows are detected from the deviation between top and bottom corresponding image signals, and a symmetry determining means reads image signals in an arbitrary domain in the shadow windows and surroundings and determines horizontal symmetry.

Abstract: A distance measuring device including an optical system for measuring a distance by trigonometric measurement, a display device for displaying an object, image following device for following an image of the object by a following window, first and second distance detecting device for calculating distances from the optical system to objects of which the images are present in the following window and the subwindow located adjacent thereto, image-following-condition detecting device for detecting a condition of following an image of the object by the following window, and window-setting renewal device for renewing the settings of all the subwindows on the basis of the data of the calculated distance and the detected image-following-condition.

Abstract: An inter-car distance detecting device of the invention includes an: image sensor for picking up the image of a car ahead through a pair of optical systems arranged substantially vertically; a display for displaying the image of the car ahead; a first window surrounding the image of the car ahead; an image tracker for tracking the image of the car ahead with the first window; a second window set in the first window; first and second distance detectors for calculating the distances from the objects held in the first and second windows, respectively; and a window position corrector for correcting the position of the first window according to the distances calculated by those distance detectors. The driver can thus readily detect the distance between his car and the car ahead. Even if the window is shifted from the image of the car ahead for instance when his car bounds, the image of the car ahead can be stably tracked. In addition, the position of the window can be corrected with high accuracy.