Abstract: The present invention provides a way to increase the density of Hall effect sensors on a MFL inline inspection tool mounting the sensors on a first circuit board which overlies a second circuit board. Op amps for the sensors which condition and filter the analog signal from the sensors are mounted on the first circuit board. Microprocessors mounted on the second circuit board receive the analog signal from the op amp and translate it into a digital signal. Use of the stacked circuit boards doubles the amount of area to mount the sensors and their op amps and microprocessors while maintaining the same footprint. This results in being able to increase the number of Hall effect sensors in that footprint area. In other embodiments the number of layers of circuit boards may be increased beyond two.

Abstract: A system and method for correcting pixel intensities for output on a video display is disclosed. In one embodiment, the method includes the operation of generating an interpolation table having a plurality of interpolation segment endpoints spaced over a transfer function correction curve. The plurality of interpolation segment end points are distributed logarithmically over the transfer function correction curve to increase a number of correction points along a curved portion of the transfer function correction curve without substantially increasing a total number of correction points over the entire curve. Correction values for a graphic display can be determined by interpolating between the logarithmically distributed interpolation segment endpoints.

Abstract: An apparatus for converting analog stroke display signals representing electron beam generated stroke traces into raster display information for producing a raster-scan image display. The apparatus includes a sampling circuit for sampling the analog stroke display signals to produce pixel data representing sub-pixel locations covered by the stroke traces. A frame buffer is coupled to the sampling circuit to temporarily store pixel data. A filter is coupled to the frame buffer for calculating brightness of pixels based upon the amount of coverage of the pixels by a stroke trace. In addition, a raster-scan display device is coupled to the filter for receiving the pixel data from the filter to produce a raster-scan image.