Abstract: A method of managing a printing system in which print jobs are disposed with a print queue, wherein a so-called “acting object”, is provided within the print queue to behave as a separate job, and is operative for specifying one or more system commands, without further specifying a actual print job. When the acting object reaches the top of the print queue, its system command is executed. Examples of such system commands are an interruption of the print queue processing or a change of default printing and/or printer parameters.

Abstract: A method of managing a printing system in which print jobs are disposed with a print queue, wherein a so-called “acting object”, is provided within the print queue to behave as a separate job, and is operative for specifying one or more system commands, without further specifying a actual print job. When the acting object reaches the top of the print queue, its system command is executed. Examples of such system commands are an interruption of the print queue processing or a change of default printing and/or printer parameters.

Abstract: A reproduction device includes a scanner, memory for storage of electrical image information, a printer and an operating device. The operating device comprises a display screen for the display of apparatus functions for selection, a first selection device for selecting a group of apparatus functions to be displayed on the display screen, and a second selection device for selecting the displayed apparatus functions or options thereof. The apparatus functions are grouped in a first group of apparatus functions relating to all the document sheets of a document for scanning, copying or printing, a second group relating to a specific document sheet of a document and a third group relating to a specific area of a specific document sheet. The first selection device is suitable for selecting directly from a standard basic menu at least some of the functions from one of the groups of functions.

Abstract: The invention relates to the halftoning of grey values of pixels obtained by a photoelectric scanning of an image. The grey values of the pixels for processing are thresholded, the quantisation error which occurs in these circumstances being added to the grey value of an adjacent yet to be thresholded and situated in a first or second direction of the image. The selection of a pixel in the first or second direction is determined in these conditions by the differences in grey values of not more than two pixels arranged in both directions and situated in the vicinity of the thresholded pixel. The pixel is preferably selected in the direction in which the smallest difference in grey value is encountered, i.e. not in the direction of the grey value gradient but exactly perpendicularly to it. It has been found that the edge transitions can be reproduced most sharply in this way.

Abstract: A method of selectively assigning to a picture element to be imaged with a color reproduction system a pertinent (permanent) indication relating to the distinguishing of color with respect to picture element, wherein, on the basis of the associated parameter values related to color saturation and intensity, a choice is first made for that picture element from a permanent indication of colorlessness a permanent indication of color behavior, and a provisional indication concerning an undefined color behavior. In the case of a picture element having a provisional indication, this indication is then converted to a permanent indication on the basis of the results of an analysis of the distribution of parameter values in the color space with respect to picture elements occurring within an environment of the associated picture element. According to this method, pastel hues can be reproduced in a logical and perceptually acceptable manner despite the presence of scanner noise.

Abstract: A direct conversion receiver for demodulating an FM signal converted frequency down converts the signal to quadrature related baseband signals (I,Q). These signals are applied by way of respective d.c. blocking capacitors (16, 18) and differentiating circuits (26, 28) to a differential arctan demodulator (20). The action of the differentiating circuits (26, 28) is to remove any d.c. component in the I and Q signals and to perform a frequency shaping which enables the demodulator (20) to recover correctly the modulating information. Measures are disclosed to overcome the effects of 180 degree phase jumps which will occur when the direction of rotation of the phasor reverses and of frequency dependent amplitude scaling introduced into the differentiated signals (I', Q').