Apparatus and method for image data processing apparatus capable of correcting dots of bit-mapped image data with a relatively smaller-sized memory

• US 6,262,813 B1
• Filed: 08/14/1998
• Issued: 07/17/2001
• Est. Priority Date: 08/18/1997
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Ohtani, Masakazu
• Primary Examiner(s): LEE, TOMMY D
• Application Number:
  US09/134,162
• Time in Patent Office: 1,068 Days
• Field of Search: 382/181, 382/190, 382/195, 382/205, 382/266, 382/267, 382/269, 358/1.9
• US Class Current: 358/1.9
• CPC Class Codes: G06T 5/20 using local operators

Abstract

An image data processing apparatus that conserves a memory used for correcting a dot of a bit-mapped image data includes a data window, a pattern recognition mechanism, a determining mechanism, an information converter, and a memory block. The data window reads the bit-mapped image data by capturing dot patterns. The pattern recognition mechanism recognizes a figure of a line segment formed between black and white dot areas included in the captured dot pattern. The pattern recognition mechanism also generates a n-bit code that has a value corresponding to the recognized figure of the line segment. The n-bit code potentially has 2ⁿ different values for representing specific figures of the line segment. The determining mechanism determines whether the dot of interest needs a correction. The information converter converts values of the n-bit code to one of two predetermined values for white and black dots of interest when the dot of interest needs no correction, and outputs the n-bit code without conversion when the dot of interest needs the correction. The memory block stores a number of correction data which are accessed with the n-bit code. The number of stored correction data includes only correction data for cases when the dot of interest needs the correction and for two cases when the dot of interest needs no correction, and is made smaller than 2ⁿ. Each of the correction data stored in the memory block uniquely corresponds to one of the two different values, although resultant values of the n-bit code may become discrete.

Claims

1. An image data processing apparatus, comprising:

a data window which successively captures dot patterns, each dot pattern having a dot of interest and surrounding dots, to read data of bit-mapped image data;

a pattern recognition mechanism recognizing a figure of a line segment formed between black and white dot areas included in each of said captured dot patterns, based on said read data from each of said dot patterns, the pattern recognition mechanism generating a n-bit code that has a value corresponding to said recognized figure of the line segment, where n is an integer, the n-bit code having up to 2ⁿ different values each representing a specific figure of the line segment;

a determining mechanism determining whether said dot of interest needs a correction based on the value of said n-bit code;

an information converter converting a plurality of values of said n-bit code to one of two predetermined values which indicate whether said dot of interest is white or black when said dot of interest needs no correction, and then outputting said n-bit code having one of said two predetermined values, and outputting said n-bit code without conversion when said dot of interest needs said correction;

a memory block storing a number of correction data, and including correction data for cases when said dot of interest needs correction and for two substituting cases when said dot of interest needs no correction, each of said correct data uniquely corresponding to one of said 2ⁿ different values, and then outputting one of said plurality of correction data when accessed with said corresponding n-bit code.

2. The image data processing apparatus according to claim 1, further comprising a weight rearrangement unit which converts a plurality of said n-bit codes having said discrete values into n-bit codes having serial-ordered values, and which outputs said converted n-bit codes to said memory block.

3. The image data processing apparatus according to claim 1, further comprising a memory select unit that selects a memory area to be used from among a plurality of memory areas included in said memory block.

4. The image data processing apparatus according to claim 3, wherein each of said plurality of memory areas included in said memory block stores said plurality of correction data, having an image resolution different from other memory areas, and said memory select unit is used for selecting said resolution.

5. An image data processing apparatus, comprising:

data window means for successively capturing dot patterns, each dot pattern having a dot of interest and surrounding dots, to read data of bit-mapped image data;

pattern recognition means for recognizing a figure of a line segment formed between black and white dot areas included in each of said captured dot patterns, based on said read data from each of said dot patterns, and for generating a n-bit code that has a value corresponding to said recognized figure of the line segment, where n is an integer, the n-bit code having up to 2ⁿ different values each representing a specific figure of the line segment;

determining means for determining whether said dot of interest needs a correction based on the value of said n-bit code;

information converting means for converting a plurality of values of said n-bit code to one of two predetermined values which indicate whether said dot of interest is white or black when said dot of interest needs no correction, and for then outputting said n-bit code having one of said two predetermined values, and for outputting said n-bit code without conversion when said dot of interest needs said correction;

memory block means for storing a number of correct data, and including correction data for cases when said dot of interest needs correction and for two substituting cases when said dot of interest needs no correction, each of said correction data uniquely corresponding to one of said 2ⁿ different values, and for then outputting one of said plurality of correction data when accessed with said corresponding n-bit code.

6. The image data processing apparatus according to claim 5, further comprising weight rearrangement means for converting a plurality of said n-bit codes having said discrete values into n-bit codes having serial-ordered values and for outputting said converted n-bit codes to said memory block means.

7. The image data processing apparatus according to claim 5, further comprising memory select means for selecting a memory area to be used from among a plurality of memory areas included in said memory block means.

8. The image data processing apparatus according to claim 7, wherein each of said plurality of memory areas included in said memory block means stores said plurality of correction data, having an image resolution different from other memory areas, and said memory select means is used for selecting said resolution.

9. A method of conserving a memory in use of operations for correcting dots of bit-mapped image data in an image data processing apparatus, said method comprising the steps of:

successively capturing dot patterns, each dot pattern having a dot of interest and surrounding dots, to read data of bit-mapped image data;

recognizing a figure of a line segment formed between black and white dot areas included in each of said captured dot patterns, based on said read data from each of said dot patterns;

generating a n-bit code that has a value corresponding to said recognized figure of the line segment, where n is an integer, the n-bit code having up to 2ⁿ different values each representing a specific figure of the line segment;

determining whether said dot of interest needs a correction based on the value of said n-bit code;

converting a plurality of values of said n-bit code to one of two predetermined values which indicate whether said dot of interest is white or black, when said dot of interest needs no correction;

outputting said n-bit code having one of said two predetermined values;

outputting said n-bit code without conversion when said dot of interest needs said correction;

storing a number of correction data, including correction data for cases when said dot of interest needs correction and for two substituting cases when said dot of interest needs no correction, each of said correction data uniquely corresponding to one of said 2ⁿ different values; and

outputting one of said plurality of correction data when being accessed with said corresponding n-bit code.

10. The method according to claim 9, further comprising the steps of converting a plurality of said n-bit codes having said discrete values into n-bit codes having serial-ordered values, and sending said converted n-bit codes to be used as addresses in said step of outputting one of said plurality of correct data.

11. The method according to claim 9, further comprising the step of selecting a memory area to be used from among a plurality of memory areas in which said number of correct data are stored in said storing step.

12. The method according to claim 11, wherein each of said plurality of memory areas storing said plurality of correction data has an image resolution different from other memory areas, and said selecting step is used for selecting said resolution.