Method of storing character patterns and character pattern utilization system

• US 4,992,954 A
• Filed: 08/03/1988
• Issued: 02/12/1991
• Est. Priority Date: 08/05/1987
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fukasawa, Minoru, Takeda, Haruo
• Primary Examiner(s): Harkcom, Gary V.
• Assistant Examiner(s): Zimmerman, Mark K.
• Application Number:
  US07/227,718
• Time in Patent Office: 923 Days
• Field of Search: 364/518, 364/519, 340/735, 340/790, 341/65, 341/67, 358/260
• US Class Current: 715/223
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 2215/0031 Compressed bit maps
• CPC Class Codes: G06K 2215/0051 from compressed bitmap, e.g. run length
• CPC Class Codes: H03M 7/42 using table look-up for the coding or decoding process, e.g. using read-only memory H03M7/4006 takes precedence

Abstract

In a character pattern utilization system provided with a plurality of character patterns differing in size or style from one another for each of a plurality of characters which are associated with corresponding character codes, the character patterns of each type are compression-coded beforehand using one of a plurality of code tables which corresponds to the character types. Upon designation of a code and a pattern type for a character to be outputted, the compression-coded character pattern corresponding to it is restored using the code table corresponding to said pattern type and is outputted.

Claims

1. A character pattern utilization system provided with a plurality of different types of character patterns for each of a plurality of character, each character having a corresponding character code, said system comprising:

a plurality of code table means for defining particular coding rules corresponding to the character pattern types;

pattern file means having a plurality of file areas each of which corresponds to a character pattern type and has stored therein a set of compressed character patterns obtained by encoding a set of original character patterns according to one of said coding rules which corresponds to the character pattern type of said original character patterns; and

reading and restoring means for reading from said pattern file means, upon designation of a character code and a character pattern type, a compressed character pattern of said designated character pattern type corresponding to the designated character code, and for restoring the compressed character pattern to an original character pattern according to a coding rule defined in one of said code table means which corresponds to said designated character pattern type.

2. The character pattern utilization system according to claim 1, further comprising:

management table means for defining relationships among character codes, character pattern types and addresses of compressed character patterns stored in said pattern file means to be accessed; and

wherein

said reading and restoring means refers to said management table to access one of said plurality of file areas.

3. The character pattern utilization system according to claim 1, wherein:

each of said compressed character patterns in a same file area is of a fixed length which is determined depending upon a character pattern type to which it belongs.

4. The character pattern utilization system according to claim 1, wherein:

each of said code table means defines respective correspondence of run lengths of black picture elements and of white picture elements with codes;

said file means having stored therein each compressed character pattern in a form of a combination of said codes.

5. A method of storing at least two groups of compressed character patterns in a memory means, comprising:

a first step of converting a first group of original character patterns belonging to a first character type to a first group of individually compressed character pattern records by coding in accordance with a first predetermined coding rule while obtaining a maximum record length among said compressed character pattern records;

a second step of converting said first group of said original character patterns to a group of individually compressed character pattern records in accordance with said first predetermined coding rule, while adjusting each record length to the maximum length and storing said compressed character pattern record thus obtained in said memory means; and

,

repeating said first and second steps for a second group of original character patterns belonging to a second character type by applying a second coding rule different from said first predetermined coding rule.

6. The method of storing compressed character patterns according to claim 5, further comprising the steps of:

analyzing a number of said plural original patterns to detect features common to the original character patterns belonging to said group; and

preparing a coding rule in accordance with said features, said first and second steps being carried out by applying said coding rules as said predetermined coding rule.

7. The method of storing compressed character patterns according to claim 6, further comprising;

a step of modifying said predetermined coding rule after said first step so as to shorten said maximum length in accordance with features of an original character pattern which, in the compressed form thereof, has said maximum record length;

each of said original character patterns being coded in said second step in accordance with said modified coding rule and stored in said memory means in the form of fixed length record of said shortened maximum length.

8. A method of storing a group of compressed character patterns in a memory means, comprising:

a first step of converting a group of original character patterns belonging to one character type to a group of individually compressed character pattern records by coding in accordance with a predetermined coding rule while obtaining a maximum record length among said compressed character pattern records;

a second step of converting the group of said original character patterns to a group of individually compressed character pattern records in accordance with said predetermined coding rule, while adjusting each record length to the maximum length and storing all said records in said memory means in a predetermined record size;

a third step of analyzing a number of said plural original patterns to detect features common to the original character patterns belonging to said group; and

,

a fourth step of preparing a coding rule in accordance with said features, said first and second steps being carried out by applying said coding rule as said predetermined coding rule.

9. The method of storing compressed character patterns according to claim 8, further comprising;

the step of modifying said predetermined coding rule after said first step so as to shorten said maximum length in accordance with features of an original character pattern which, in the compressed form thereof, has said maximum record length;

each of said original character patterns being coded in said second step in accordance with said modified coding rule and stored in said memory means in the form of fixed length record of said shortened maximum length.