Method and apparatus for processing image

• US 4,929,979 A
• Filed: 01/27/1989
• Issued: 05/29/1990
• Est. Priority Date: 01/29/1988
• Status: Expired due to Fees

• Current Assignee: Konica Corporation (Konica Minolta Inc.)
• Original Assignee: Konica Corporation (Konica Minolta Inc.)
• Inventors: Abe, Yoshinori, Kimoto, Tetsuo
• Primary Examiner(s): Hix, L. T.
• Assistant Examiner(s): RUTLEDGE, DELLA J
• Application Number:
  US07/303,724
• Time in Patent Office: 487 Days
• Field of Search: 355/38, 355/77, 355/327, 358/75, 358/80, 358/457, 358/443, 358/447
• US Class Current: 355/38
• CPC Class Codes: H04N 1/4074 using histograms
• CPC Class Codes: H04N 1/6027 Correction or control of colour gradation or colour contrast H04N1/6058 takes precedence
• CPC Class Codes: H04N 1/64 Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor H04N19/00 takes precedence

Abstract

According to a method and apparatus for processing an image, density data representing a density of each pixel of original image data and color data representing a color of each pixel are generated. The density and color data are generated as parallel data. A write mode of a memory is set. A memory content is repeated updated in correspondence with the density data and the color data. A read mode of the memory is set. A memory content corresponding to one of the color data is externally read out. Threshold values are set in units of color data on the basis of the memory content read out from the memory. Recording density data having a smaller number of bits is formed by the set threshold values on the basis of the density data. Recording is performed on the basis of the formed recording density data.

Claims

1. An image processing apparatus comprising:

pixel data generating means for generating density data representing a density of each pixel of original image data and color data representing a color of each pixel, the density and color data being parallel data;

mode setting means for outputting a mode setting signal for setting a write mode and a read mode;

memory means capable of being arbitrarily set in the write mode and the read mode in response to the mode setting signal, said memory means being operated such that a memory content is changed in correspondence with the density data and the color data in the write mode and that a memory content corresponding to the color data externally accessed is read out in the read mode;

threshold value setting means for setting threshold values in units of color data on the basis of the memory content read out from said memory means in the read mode;

recording density data forming means for forming recording density data having a smaller number of bits by the set threshold values on the basis of the density data; and

recording means for performing recording on the basis of the recording density data.

2. An image processing apparatus comprising:

pixel data generating means for generating density data representing a density of each pixel of original image data and color data representing a color of each pixel, the density and color data being parallel data;

mode setting means for outputting a mode setting signal for setting a write mode and a read mode;

memory means capable of being arbitrarily set in the write mode and the read mode in response to the mode setting signal, said memory means being operated such that, in the write mode, said memory is addressed by the density data and the color data and data stored at an accessed address is incremented, and, in the read mode, all addresses corresponding to one of the color data which is externally accessed are accessed and data stored at the accessed addresses are read out;

control data forming means for forming control data on the basis of a series of data read out from said memory means in the read mode; and

processing means for processing the density data on the basis of the control data.

3. An apparatus according to claim 2, wherein said control data forming means reads out data corresponding to a plurality of color data from said memory means, adds the readout data, and forms the control data on the basis of the sum.

4. An image processing apparatus comprising:

image reading means consisting of a plurality of linear photoelectric transducer elements and an optical system for simultaneously forming an optical image from a document onto said plurality of photoelectric transducer elements, said plurality of photoelectric transducer elements being arranged to perform a main scan of the document and a subscan of the document at a speed corresponding to a designated magnification in a direction perpendicular to a direction of the main scan, so that each of said photoelectric transducer elements outputs a read signal in units of scan lines;

pixel data generating means for generating density data representing a density of each pixel of original image data and color data representing a color of each pixel, the density and color data being parallel data;

mode setting means for outputting a mode setting signal for setting a write mode and a read mode;

memory means capable of being arbitrarily set in the write mode and the read mode in response to the mode setting signal, said memory means being operated such that, in the write mode, said memory is addressed by the density data and the color data and data stored at an accessed address is incremented, and, in the read mode, all addresses corresponding to one of the color data which is externally accessed are accessed and data stored at the accessed addresses are read out;

threshold value setting means for setting threshold values in units of color data on the basis of the memory content read out from said memory means in the read mode;

recording density data forming means for forming recording density data having a smaller number of bits by the set threshold values on the basis of the density data; and

recording means for performing recording on the basis of the recording density data.

5. A method of processing an image, comprising the steps of:

(a) generating density data representing a density of each pixel of original image data and color data representing a color of each pixel, the density and color data being parallel data;

(b) setting a write mode of memory means;

(c) repeatedly updating a memory content in correspondence with the density data and the color data;

(d) setting a read mode of the memory means;

(e) externally reading out a memory content corresponding to one of the color data;

(f) setting threshold values in units of color data on the basis of the memory content read out from the memory means;

(g) forming recording density data having a smaller number of bits by the set threshold values on the basis of the density data; and

(h) performing recording on the basis of the recording density data formed in step (g).

6. A method of processing an image, comprising the steps of:

(a) generating density data representing a density of each pixel of original image data and color data representing a color of each pixel, the density and color data being parallel data;

(b) setting a write mode of memory means;

(c) repeatedly updating a memory content in correspondence with the density data and the color data;

(d) setting a read mode of the memory means;

(e) externally reading out a memory content corresponding to one of the color data;

(f) setting threshold values in units of color data on the basis of the memory content read out from the memory means;

(g) regenerating density data representing a density of each pixel of original image data and color data representing a color of each pixel, the density and color data being parallel data;

(h) forming recording density data having a smaller number of bits by the threshold values set in step (f) on the basis of the density data obtained in step (g); and

(i) performing recording on the basis of the recording density data formed in step (h).

7. A method of processing an image, comprising the steps of:

(a) generating density data representing a density of each pixel of original image data and color data representing a color of each pixel, the density and color data being parallel data;

(b) setting a write mode of memory means;

(c) repeatedly addressing the memory by the density data and the color data and incrementing data at an accessed address;

(d) setting a read mode of the memory means;

(e) accessing all addresses corresponding to one of the color data and reading out data at the accessed addresses;

(f) outputting control data on the basis of a series of data read out from the memory means; and

(g) processing the density data on the basis of the control data.