Abstract: The present invention relates to a method for producing multitone image data from data representative of an original image and, in particular, for producing multitone image data with a set of N output darkness levels U greater than 2 from original darkness values V.sub.o representative of an original image.
Abstract: The present invention relates to a method for producing multitone image data from data representative of an original image and, in particular, for producing multitone image data with a set of N output darkness levels U greater than 2 from original darkness values V.sub.o representative of an original image.
Abstract: A vibratory, time variant, pseudorandom sonar system includes a computer controlled pseudorandom digital sweep frequency source, a digital/analog converter for changing the digital output of the source to an analog output and a power amplifier for amplifying the analog output to drive a vibrator or other suitable transducer for injecting corresponding sound waves into a body of water for target detection. A memory is provided for storing the source's digitized output.A target reflects the sound waves for detection by 3 arbitrary non-colinear hydrophones which outputs a plurality of analog signals corresponding to the reflected sound waves to a plurality of channels. Each channel includes a preamplifier and an analog/digital converter for digitizing the analog electrical signals for storage in the memory. A computer controlled timer determines the time lapse between the injection of the source signal and detection of the reflected source signal by each hydrophone of the hydrophone array, for storage in memory.