Image processing apparatus and method

• US 7,103,221 B2
• Filed: 11/12/2002
• Issued: 09/05/2006
• Est. Priority Date: 04/06/1995
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Matsukubo, Yushi, Yamakawa, Junichi, Ohta, Ken-ichi, Funada, Masahiro
• Primary Examiner(s): Chen, Wenpeng
• Application Number:
  US10/291,496
• Publication Number:
  US 20030067632A1
• Time in Patent Office: 1,393 Days
• Field of Search: 382/173, 382/175, 382/186, 382/184, 382/176, 382/205, 382/270, 382/274, 358/455, 358/456, 358/466, 358/459, 358/458, 358/465, 358/448, 358/296, 358/518, 358/447, 358/445, 358/464, 358/3.21, 358/3.03
• US Class Current: 382/173
• CPC Class Codes: G06K 15/02 using printers
• CPC Class Codes: G06K 15/1822 Analysing the received data before processing
• CPC Class Codes: G06K 15/1852 involving combining data of different types
• CPC Class Codes: G06K 2215/0065 Page or partial page composition
• CPC Class Codes: H04N 1/40062 Discrimination between different image types, e.g. two-tone, continuous tone
• CPC Class Codes: H04N 1/4056 the pattern varying in one dimension only, e.g. dash length, pulse width modulation [PWM]

Abstract

In order to produce a high-quality output of an image which is a mixture of images having different characteristics, there is provided an image processing apparatus having an image memory storing an entered color image and a feature detector, arranged for detecting a feature signal from the entered color image and storing the feature signal in the image memory. The feature signal represents a feature of the entered color image. An outputter is arranged for reading an image signal of the entered color image and the feature signal thereof out of the image memory, and outputting the image and feature signals as a recording signal. Processors are arranged for respectively processing one of a number of color components, which represent color image information, in accordance with the recording signal. The detection and storage in the image memory of feature signals and the readout of the image signal and associated feature signal from the image memory are performed in parallel.

Claims

1. An image processing apparatus comprising:

a developing means for developing entered image information described in a page description language and storing developed image data for each pixel in first storage means;

a discriminating means for discriminating a characteristic of an image, pixel by pixel, by referring to the image data that have been stored in said first storage means, and storing a discrimination code representing a result of discrimination in second storage means, wherein said discriminating means performs discrimination processing by referring to image data of an area comprising the pixel of interest and a plurality of pixels surrounding said pixel of interest, and said processing is based upon items of image data having different values present in said area and a maximum value of differences between said pixel of interest and said pixels surrounding said pixel of interest;

a readout means for reading the image data stored in said first storage means and reading the discrimination code, which corresponds to the image data pixel by pixel, out of said second storage means; and

a converting means for converting the image data, which have been read out of said first storage means by said readout means, to a pulse-width modulated signal having a period according to the discrimination code read out of said second storage means by said readout means.

2. An image processing method comprising the steps of:

developing entered image information described in a page description language and storing developed image data for each pixel in a first memory;

discriminating a characteristic of an image, pixel by pixel, by referring to the image data that have been stored in the first memory, and storing a discrimination code representing a result of discrimination in a second memory, wherein the discriminating step performs discrimination processing by referring to image data of an area comprising the pixel of interest and a plurality of pixels surrounding the pixel of interest, and the processing is based upon items of image data having different values present in the area and a maximum value of differences between the pixel of interest and the pixels surrounding the pixel of interest;

reading the image data stored in the first memory and reading the discrimination code, which corresponds to the image data pixel by pixel, out of the second memory; and

converting the image data, which have been read out of the first memory in the reading step, to a pulse-width modulated signal having a period according to the discrimination code read out of the second memory in the reading step.