Abstract: A method and apparatus are described for removing noise by smoothing fine resistivity measurements made with a tool from inside a borehole penetrating an earth formation. Pixel values representative of the resistivity measurements are examined to determine the directions of features in the measurements and a smoothing of the pixel values is then made along the measured directions. The orientations of the features are obtained with a similarlity investigation of pixels in sub-array windows along parallel lines whose slope is varied. Optimal slope lines along which the pixel values in a window best resemble each other are determined as the direction of the features. Smoothing is done along the optimal slope lines. Substantially noise free pixel measurements are obtained to enable subsequent automatic signal processing such as the detection of edges between layers of different resistivity. The edges are recorded with an emphasis on a visual display for enhanced visual analysis.

Abstract: A system for the metering of encrypted postage and similar indicia includes a device for printing such indicia and a device for reading such indicia. The printing is accomplished with a bar-code printer driven by signals obtained from a keyboard and from an encryption circuit. The reading is accomplished with a bar-code reader to retreive the characters, and permit the comparison of the separated coded data with a reference code to determine the accuracy of the printed material. Thereby, forgery and alteration is inhibited. Both the data and the code are imprinted by a bar-code indicia, a portion of the code being set aside for the data and a portion of the bar-code being set aside for encryption purposes. Thereby, the two portions can readily be separated to allow for automatic reading of the bar code for extraction of the message, while also allowing for automatic verification by use of the encrypted material.