Abstract: The present invention relates to methods and apparatus for requesting and receiving print jobs over a communications network. In particular, the present invention enables a user to obtain print jobs at a location which may be unspecified, and which may be remote from the source of the print job. A spooling server is used to store a print job received via the network from a print job source. A printer polling device, which may be used at a location remote from the client device, is capable of polling the spooling server via the network to identify whether any print jobs associated with the printer polling device are available for printing at a printer currently associated with the polling device. The spooling server need not initiate contact with the printer through a firewall, since it is polled by the printer polling device. Thus, network security is maintained.

Abstract: Methods and apparatus for performing colorant limitation are provided that receive input data and desired and measured or specified output response data for a print output device, and determine converted input data that accounts for differences between the measured or specified and the desired output responses of the printer. Converted input data may then be provided to a conventional colorant limitation algorithm for performing colorant limitation. Colorant-limited input data are then de-converted by accounting for differences between the desired and the measured or specified output responses of the printer.

Abstract: Color conversion apparatus and methods are provided for converting a first color value, such as an RGB, L*a*b* or XYZ color value, to a second color value, such as an RGB, CMY, CMKY, L*a*b*, L,C1C2, or XYZ color value, without saturation error.

Abstract: Color conversion apparatus and methods are provided for converting a first color value, such as an RGB, L*a*b* or XYZ color value, to a second color value, such as an RGB, CMY, CMKY, L*a*b*, L,C1C2, or XYZ color value, without saturation error.

Abstract: A method and apparatus for compression of data. The invention provides for the application of a plurality of compression schemes to the data such that improved compression ratios are achieved. A first embodiment provides for compression of each pixel by one of a plurality of different entropy-based compression schemes based upon a probability cost analysis. A second embodiment provides for compression of each pixel based on a hybrid context formed using a plurality of compression schemes for improved probability determination, and thus improved entropy encoding. In embodiments of the invention, a context compression scheme similar to JBIG is applied, as well as an inverse scheme. The context scheme forms a statistical context from a concatenated sequence of previous pixel values. The inverse scheme provides a gray value estimation method based upon previous pixel values and respective threshold values.