A method includes: receiving, at a computing device, image data encoded by delta row encoding, the image data indicating two dimensionally arranged plurality of pixels, the image data including delta data indicating difference between N-th row line and (N−1)th row line in the two dimensionally arranged plurality of pixels; pre-decoding the image data for the N-th row line using the delta data if the delta data has a size equal to or larger than a threshold while keeping the image data for the N-th row line using the delta data if the delta data has a size smaller than the threshold so as to generate intermediate codes using the computing device; and decoding and rendering the kept undecoded lines in the generated intermediate codes while rendering the decoded lines in the generated intermediate codes using the computing device.

When performing printing for every M columns, a print buffer stores printing data by dividing the data into M groups. When data is multilevel data or when performing no column thinning printing, the print buffer stores the data without dividing it. When data to be stored in the print buffer is binary data and printing is to be performed for every M columns, printing data is stored as it is divided into M groups, and these data groups are read out as they are switched for each scan of the printhead. When data to be stored in the print buffer is multilevel data or when performing no column thinning printing, data is read out without switching readout regions.

A non-transitory computer-readable recording medium stores a printing program for executing on a computer. The printing program causes the computer to function as an available capacity determining circuit and a print data transmitting circuit. The available capacity determining circuit determines an available capacity available for a print job in a storage device of the image forming apparatus. The print data transmitting circuit transmits print data to the image forming apparatus, the print data being adapted to the available capacity determined by the available capacity determining circuit. The print data transmitting circuit converts the variable print data into print data without the reuse data and transmits the converted print data to the image forming apparatus in a specific case where the available capacity is less than the variable printing capacity.

A printing apparatus performs conversion processing that converts input data corresponding to a page into image data, executes a predetermined operation for transition of a printhead to a printing standby state, in a case where image data is delayed, performs holding processing that holds the image data in a data memory, and performs retaining processing until an amount of image data held in the data memory exceeds a predetermined amount. The printing apparatus also outputs the image data in the data memory in a case where the amount of image data held in the data memory exceeds the predetermined amount, and executes printhead printing based on the output image data. In a case where input data still remains, the conversion processing for the remaining input data is performed concurrently with the printing based on the output image data.

In a method or controller to execute a proof job of a copy print job, the proof job including a printing of a proof sheet, at a first point in time first raster data for the print sheet of the copy print job is provided. After expiration of a first provisioning time period at least one first job is inserted for printing a plurality of copies of the print sheet into a print buffer. A second point in time is determined at which the print buffer includes a first number of copies of the print sheet that are to be printed, the first number being such that a time period for printing of the first number of copies is greater than or equal to a second provisioning time period for providing of second raster data for the proof sheet of the proof job. After expiration of the second provisioning time period a second job is inserted to print the proof sheet into the print buffer so that copies of the print sheet and the proof sheet are printed according to an order of the first and the second jobs in the print buffer.

A method of compositing layers by grouping the layers into a foreground group and a background group; identifying independent instructions of compositing model for execution independently from the background group and dependent instructions requiring a compositing output of a background layer in order to composite foreground layers; executing the independent instructions on the foreground layers in parallel with compositing the background layers, a first independent instruction storing a corresponding result in a first buffer and a second independent instruction storing a corresponding result in a second buffer; executing a dependent instruction by updating the second buffer using the background compositing output; and determining a compositing output for the foreground group dependent upon contents of the first buffer and the updated second buffer.

A method and system for rendering rectangle drawing objects are provided. For at least a first rectangle drawing object and a second rectangle drawing object, a determination is made if the second rectangle drawing object satisfies a predetermined condition with respect to the first rectangle drawing object. If the predetermined condition is satisfied, one-line raster image data associated with the second rectangle drawing object is generated and stored in a data buffer. The one-line raster image data indicates a filling color of the second rectangle drawing object over a first extent in a first direction. Subsequently, the one-line raster image data may be used a number of times over a second extent in a second direction perpendicular to the first direction to fill a drawing region corresponding to at least the second rectangle drawing object.

To provide an image processing apparatus capable of associating print data with channels with a simple configuration and transferring the print data to an appropriate print head, an image processing apparatus stores print data corresponding to each ink in a data buffer in association with ink information indicating each ink. The image processing apparatus includes a table retention unit which stores an address of a channel buffer associated with each of a plurality of print heads in association with the ink information, and transfers each print data to an address associated with the ink information. The image processing apparatus can rewrite an association between the addresses and the ink information stored in the table retention unit.

A print output control device operably connected to a printer, is configured to periodically check a first buffer sequentially storing print data received from the printer; accumulate, when the print data is stored in the first buffer, the stored print data in a second buffer; store, when status information on the printer is included in the print data, the status information in a status storage unit; store, when a first function is executed, in a third buffer, the print data accumulated in the second buffer to send back the stored print data as an acquisition value for the first function; and store, when a second function is executed, in a third buffer, the print data accumulated in the second buffer from when the second function is executed to send back the stored print data as an acquisition value for the second function.

An image forming apparatus for processing print data is disclosed. The image forming apparatus includes a control unit configured to control a plurality of nonvolatile storage devices having different transfer rates, and a determination unit configured to determine a nonvolatile storage device to store print data from among the plurality of nonvolatile storage devices based on information related to a size of the print data, information related to the transfer rates of the plurality of nonvolatile storage devices, and a threshold value depending on the number of sheets to be printed and output per unit time. The control unit and the determination unit are implemented by one or more processor.