Abstract: In a continuous tone image approximated by a two-dimensional array of gray scale coded points, more than one bit per picture element is required. Compression coding consists firstly of delta coding sequences representative of the successive scan lines of the continuous tone image and secondly applying them to a predictive encoder having a particular transfer function and thirdly run-length encoding the error image. Central to the invention is the observation that delta coded sequences of gray scale pel values along a given scan line having a high expectancy of alternating, i.e. 101010. Also, the gray scale trend in the ith scan line is expected to be the same as the trend of the ith - 1 scan line. Relatedly, gray scale image expansion is achieved by applying the compressed image to a run-length decoder, a predictor stage, and delta decoder.

Abstract: A conventional word organized random access memory is modified for image processing operations so that the pq image points of any 1 .times. pq subarray, any pq .times. 1 subarray, or any regularly-spaced p .times. q subarray of an rp .times. sq or smaller image array stored in the memory can be extracted or updated in a single memory cycle. The invention contemplates pq memory modules labeled from 0 to pq-1 for storing the image points, each module being capable of storing rs points in distinguishable cells, only one cell of which is randomly accessible in a single instant of time. The invention further contemplates accessing circuitry for causing each image point I(i,j) of an image array to be routed to or from a memory module M(i,j) according to the relation M(i,j)=[iq+(i/p)//q+j]//pq, where the notations "/" and "//" denote, respectively, the quotient and the remainder resulting from integer division.

Abstract: A conventional word organized random access memory is modified for image processing operations so that the pq image points of any 1 .times. pq, pq .times. 1 or pxq subarray of an rp .times. sq or smaller image array stored in the memory can be extracted or updated in a single memory cycle. The invention contemplates 2 pq memory modules labeled from 0 to 2pq-1 for storing the image points, each module being capable of storing rs/2 points in distinguishable cells, only one cell of which is randomly accessible in a single instant of time. The invention further contemplates accessing circuitry for causing each image point I(i,j) of an image array to be routed to or from a memory module M(i,j) according to the relation M(i,j)=pq[(i/p)//2]+ (iq+i/2p+j)//pq, where the notations "/" and "//" denote, respectively, the quotient and the remainder resulting from integer division.

Abstract: Sheet handling apparatus for feeding just-burst sheets along a sheet path to a stacker mechanism where the sheets are stacked on end in the same order they entered. The stacker bed is adjustable to receive any of a predetermined sizes of sheets. A plurality of feeding means is spaced along the sheet path and these feeding means are actuated to feed the predetermined size sheet by setting the stacker bed in position. As the sheets are fed along the sheet path, each sheet can be selectively laterally offset to facilitate the separation of the sheets into sets of copies, data sets or jobs.

Abstract: A heat fuser roll and the method of manufacture thereof. The roll comprises a deformable layer on a base member and the deformable layer is produced by coating the base member with a silicone gum material containing no curing agent and treating the coated base member by heating in an inert atmosphere to a temperature at which substantial cross-linking occurs for a predetermined time to produce a tough long-wearing silicone rubber deformable layer.

Abstract: A binary image containing objects comprised of black picture elements (pels) in a bit-addressable random access memory, is scanned in a predetermined order, until a black pel is encountered. The object is then encircled by a boundary follower in a clockwise direction, and each pel is recorded as it is encountered in a chain link format. Each black pel is changed to white as it is encountered provided it is not an interior boundary point. After the object has been completely encircled by the follower, encoding of the points is temporarily terminated. The follower continues to encircle the object several times, deleting black pels as it goes, until all of the black points in the object are exhausted except for the interior boundary. At this point, the remaining interior boundary pels are traced out and encoded in the same chain link format.Objects within objects are also encoded. A stack is provided to store the coordinates of the occurrence of each mode change described below.