JPH02150895A - Image data processor - Google Patents

Abstract

PURPOSE:To eliminate the need for a dedicated memory for the storage of image data which are already expanded by performing font-cache operation by copying a character image which is already expanded on a page memory to a current development object position on the same page memory. CONSTITUTION:A microprocessor 1 retrieves the table on a memory 7 by using the character code of a character to be expanded and judges whether or not the character is already expanded on the page memory 3. When the character is not registered in the table, character font data is read out of a character font memory 2 and expanded on the page memory 3 and the character code of the expanded character and the position on the page memory 3 are registered in the table. Further, when the character is already expanded and present on the page memory 3, the address of the already expanded character image on the page memory 3 is found in the table and the character image is copied to the current expansion object position. Thus, the need for the dedicated memory for the storage of the already expanded image data is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an image data processing device that controls the development of character fonts and vector fonts in a page memory during printing or display.

(Prior Art) Conventionally, there is an image data processing device that develops font data specified by a code on a page memory when printing or displaying on a display. Such a device is incorporated into a rusk scan type printer device (for example, a laser beam printer) or a CRT display control device.

By the way, some devices of this type use a technique called a font cache method to speed up the processing of the font data.

This font cache method will be explained using character font development processing in a word processor as an example.

First, it is assumed that character modifications such as emphasis, italics, and enlargement are instructed for a character font. When rendering such a character font, the processing time is longer than when rendering a font for which character decoration is not specified.

Therefore, the font cache method stores the expanded image data and its character font code in an image storage memory separate from the page memory, and searches the cache memory every time an expansion instruction is issued. As a result, when the data is exported, the developed image data is copied to the page memory, thereby eliminating the need for the same development process again. This is intended to speed up the development of character fonts that are specifically designated for character decoration.

However, in order to implement this font cache method, there is a problem in that a dedicated cache memory is required.

(Problems to be Solved by the Invention) As described above, image data processing devices that use the conventional font cache method have the problem of high costs because they require memory for storing expanded image data. .

The present invention has been made in view of the problems of the prior art, and its purpose is to provide an image that realizes a font cache without requiring a dedicated memory for storing expanded image data. An object of the present invention is to provide a data processing device.

[Structure of the invention]

(Means for Solving the Problems) An image data processing device of the present invention includes a page memory, an identification code of a font that has been expanded to this page memory, and position data of the expanded image data on the page memory. means for storing a table; and a means for storing a font to be developed by searching the table based on the identification code of the font to be developed when developing image data corresponding to an identification code of the font to be developed into the page memory; means for determining whether or not the font has already been expanded in the page memory; and when the determining means determines that the font to be expanded has already been expanded, an expanded image of the expanded font; means for copying the image from the expanded position on the page memory to the expansion target position on the page memory that is the target of the expansion instruction; The present invention includes means for rasterizing the target font to the rasterization target position on the page memory and registering the identification code of the font and the rasterized image data as constituent elements of the table.

(Function) According to the present invention, for a font that has already been expanded, the expanded image data is copied from the expanded position on the page memory to the current expansion target position,
Since the page memory is used as the font cache memory for storing the expanded image data, a dedicated memory for storing the expanded image data is not required when realizing the font cache.

(Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a printer device according to an embodiment of the present invention, and FIG. 2 is a flowchart of expansion control performed by the MPU.

1 is a microprocessor (MPU), 2 is a bit mover, 3 is a character font memory, 4 is a page memory, 5 is a mechanical interface (mechanical IF), 6 is a printer, and 7 is a table memory, and the printer device is composed of these. be done.

The microprocessor 1 controls the entire printer device based on instructions from a host computer (not shown), and performs font cache type printer control as shown in FIG.

The character font memory 2 stores character font data, and the page memory 3 is a bitmap memory that stores character images for printing. The character font data in character font memory 2 is transferred to page memory 3 by bit mover 4.
will be expanded to. This bit mover 4 also has the function of partially transferring the image data on the page memory 3 to another location in the same page memory 3.

The character image data on the page memory 3 is supplied to a printer mechanism 6 via a mechanical interface 5, and is printed by this printer mechanism 6.

The cache table memory 7 stores a character code containing information such as the type of character shape, the number of dots in the character structure, the focus of decoration, etc. as an identification code of the character font already expanded on the page memory 3. The address on the page memory 3 where the corresponding character image is stored is stored.

Next, the printing operation under the control of the microprocessor 1 will be explained with reference to FIG. In the command from the host computer to the microprocessor 1, the expansion instruction is issued before the print instruction, and in this example, after the instruction to expand the characters of the entire document is issued character by character, The entire print instruction is issued. In addition, for example, an instruction to develop one page of a document is issued character by character, then an instruction to print that one page is issued, and then, after an instruction to develop the next page, an instruction to print that page is issued. There is also a method in which .

First, when the microprocessor 1 receives a command from the host computer, it interprets the command (step S1) and determines whether the command is an expansion instruction or a print instruction (step S2).

As a result, if the command is a character expansion instruction, the table in the memory 7 is searched using the character code of the character to be expanded (step S3), and it is determined whether or not the character has already been expanded in the page memory 3. Make a judgment (step S4)
.

As a result, if the corresponding character is not registered in the table, the character font data is taken out from the character font memory 2 and expanded onto the page memory 3 using the bit mover 4 (step S5). Further, the character code of the expanded character and its position on the page memory 3 are registered in the table (step S6).

Further, as a result of the judgment in step S4, if the corresponding character has already been expanded and exists on the page memory 3, the address of the expanded character image on the page memory 3 is obtained from the table, and the expanded character image is Copy to the expansion target position using bit mover 4 (step S7)
.

These steps are repeated each time an expansion instruction is received from the host computer, and when the entire document has been expanded, a print instruction command is sent from the host computer.

If this print instruction is received, the determination in step S2 is Y.
es, gives operation instructions to the printer mechanism 6 via the mechanical interface 5 (step S8), and then also supplies and transfers the data on the page memory 3 to the printer mechanism 6 via the mechanical interface 5. . Furthermore, after printing is completed, the cache table in the memory 7 is initialized (step S9).

This completes the series of print processing.

As described above, according to this embodiment, if the character for which the expansion instruction has been performed has already been expanded, the expanded character image on the page memory 3 is used as the current expansion target on the same page memory 3. The font is cached by copying it to the specified location, eliminating the need for dedicated memory for storing expanded image data.

Although one embodiment has been described above, the present invention is not limited to this embodiment. For example, it can be applied not only to font caching when modifying characters, but also to vector fonts. Furthermore, it can be applied not only to print control but also to display control.

〔Effect of the invention〕

As explained above, according to the present invention, for fonts that have already been expanded, the expanded image data is transferred from the expanded position on the page memory to the current expansion target position, and the expanded image data is stored. Since the page memory is used as the font cache memory for the font cache, it is possible to realize a font cache without requiring a dedicated memory for storing expanded image data.

3 is a flowchart showing control details.

DESCRIPTION OF SYMBOLS 1... Microprocessor, 2... Character font memory, 3... Page memory, 4... Bit mover, 5...
...Mechanical interface, 6...Printer mechanism, 7
...Table memory for cache

Claims (1)

[Scope of Claims] A page memory in which image data is expanded, and means for storing a table comprising an identification code of an expanded font to this page memory and position data of the expanded image data on the page memory. When the image data corresponding to the identification code of the font to be developed is to be developed into the page memory, the font to be developed is stored in the page memory by searching the table based on the identification code of the font to be developed. means for determining whether or not the font to be developed has already been developed; and when the determining means determines that the font to be developed has already been developed, the developed image data of the developed font data is means for copying from the expanded position on the page memory to the expansion target position on the page memory that is the target of the expansion instruction; An image data processing device comprising: means for rasterizing a target font to the rasterization target position on the page memory, and registering an identification code of the font data and the rasterized image data as constituent elements of the table.