Image processing apparatus for rapid production of a hard copy of a video image in which input image signal processing parameters are set while a record medium is being positioned at a recording position

• US 4,727,434 A
• Filed: 03/08/1985
• Issued: 02/23/1988
• Est. Priority Date: 03/14/1984
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kawamura, Hideaki
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/709,722
• Time in Patent Office: 1,082 Days
• Field of Search: 358/75, 358/78, 358/80, 358/280, 358/283, 358/285, 358/256
• US Class Current: 358/448
• CPC Class Codes: H04N 1/4074 using histograms
• CPC Class Codes: H04N 1/6019 using look-up tables H04N1/6025 takes precedence

Abstract

An image processing apparatus can rapidly produce a hard copy of a video image by setting parameters for processing an input image signal while a record medium is being advanced to an initial recording position. The parameters which are set are upper and lower limits for normalizing the input image signal, and are determined by performing histogram processing on the input image signal. In addition, the processing apparatus may include a plurality of combined normalization and gamma correction reference tables for processing the input image signal. One of the plurality of combined reference tables is selected on the basis of the upper and lower limits determined by the histogram processing of the input image signal. Alternatively, separate normalization and gamma correction reference tables may be used.

Claims

1. An image recording apparatus comprising:

recording means for recording on a record medium a visual image represented by an image signal;

processing means for processing the image signal for recording by said recording means;

positioning means for positioning the record medium at a recording position of said recording means;

setting means for setting parameters necessary for said processing means to process the image signal; and

control means for activating said setting means while said positioning means is operating.

2. An image recording apparatus according to claim 1, wherein said setting means sets upper and lower limits for normalization of the image signal.

3. An image recording apparatus according to claim 1, wherein said positioning means includes conveying means for conveying the record medium to the recording position.

4. An image recording apparatus according to claim 3, wherein said conveying means includes a stepping motor.

5. An image recording apparatus according to claim 1, wherein said setting means includes histogram processing means for producing a histogram representing a frequency distribution of each of a plurality of density levels of the image signal.

6. An image recording apparatus according to claim 5, wherein said positioning means includes a stepping motor for conveying the record medium to the recording position.

7. An image recording apparatus according to claim 6, wherein said control means alternately and repeatedly operates said histogram processing means and said stepping motor.