Color image processing apparatus with a plurality of addressable characteristic conversion tables for compensating for differences in the spectral characteristics of different input devices

• US 4,679,074 A
• Filed: 03/14/1984
• Issued: 07/07/1987
• Est. Priority Date: 03/17/1983
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sugino, Takashi, Sugiura, Susumu, Hirose, Naoya
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Svihla, Randall S.
• Application Number:
  US06/589,464
• Time in Patent Office: 1,210 Days
• Field of Search: 358/75, 358/76, 358/78, 358/32, 358/80, 358/164, 358/280
• US Class Current: 358/523
• CPC Class Codes: H04N 1/6052 Matching two or more picture signal generators or two or more picture reproducers

Abstract

There is disclosed an image processing apparatus for processing an image signal in which the mode of image processing is rendered variable to adapt to plural input devices. More specifically, a conversion matrix circuit receives image signals from one of a plurality of different input devices and converts the image signals into corrected additive primary color signals red, green and blue. The conversion matrix circuit compensates for any differences in the spectral characteristics of the different input devices. The matrix includes a plurality of conversion tables stored in memory for performing the conversion. A selected one of the conversion tables is addressed by the image signals.

Claims

1. A color image signal processing apparatus, comprising:

input means for receiving a color image signal connectable to plural kinds of color input devices, wherein said input devices may have different spectral characteristics;

conversion means for converting characteristics of the color image signal received by said input means according to one of a plurality of predetermined conversion tables, said one conversion table being addressed by the color image signal received by said input means and outputting a processed color image signal;

switching means for selecting said one conversion table of said conversion means according to the kind of color input device connected to said input means;

output means for receiving the processed color image signal, said output means being common to said plural kinds of input devices; and

processing means for receiving the processed color image signal outputted from said one conversion table and providing the processed color image signal to said common output means.

2. A color image signal processing apparatus according to claim 1, wherein each of said conversion tables is adapted to convert the characteristics of the color image signal received by said input means according to a predetermined conversion matrix.

3. A color image signal processing apparatus according to claim 2, wherein said conversion means comprises a memory for storing the conversion tables.

4. A color image signal processing apparatus according to claim 1, wherein said conversion means is adapted to convert the characteristics of said color image signal received by said input means according to said predetermined conversion tables in order to compensate for any differences between the spectral characteristics of the plural kinds of color input devices.

5. A color image signal processing apparatus according to claim 1, wherein said output means is a color printer.

6. A color image signal processing apparatus according to claim 1, wherein said processing means includes a complementary color conversion circuit, a tonality correction circuit and a masking circuit.

7. A color image signal processing apparatus according to claim 1, wherein said plural kinds of color input devices include color image data storing means and color image reading means.

8. A color image signal processing apparatus according to claim 1, wherein said switching means is adapted to select said one of said predetermined conversion tables in accordance with the connection of said color input devices to said input means.

9. A color image data processing apparatus, comprising:

color image data storing means for storing color image data, said storing means being a source for producing first color image data;

color image reading means for reading a color image, said reading means being a source for producing second color image data;

input means for receiving color image data connectable to either said color image data storing means or to said color image reading means;

conversion means for converting characteristics of the color image data received by said input means according to one of a plurality of predetermined conversion tables, said one conversion table being addressed by the color image data received by said input means and outputting processed color image data;

switching means for selecting said one conversion table of said conversion means according to whether the source for producing the color image data is said color image data storing means or said color image reading means, said source being connected to said input means;

an image reproduction means being common to said color image data storing means and to said color image reading means; and

processing means for receiving the processed color image data outputted from said one conversion table and providing the processed color image data to said common image reproduction means.

10. A color image signal processing apparatus, comprising:

input means for receiving a color image signal connectable to plural kinds of color input devices, wherein said input devices may have different spectral characteristics;

conversion means for converting characteristics of the color image signal received by said input means according to predetermined conversion parameters and outputting a processed color image signal;

switching means for selecting the conversion parameters of said conversion means according to the kind of color input device connected to said input means, said switching means being adapted to select said conversion parameters in accordance with the connection of said color input devices to said input means;

output means for receiving the processed color image signal, said output means being common to said plural kinds of color input devices; and

processing means for receiving the processed color image signal outputted from said conversion means and providing the processed color image signal to said output means.

11. A color image signal processing apparatus according to claim 10, wherein said conversion means comprises a memory which is addressed by the color image signal received by said input means.

12. A color image signal processing apparatus according to claim 10, wherein said conversion means is adapted to convert the characteristics of the color image signal received by said input means according to one of a plurality of predetermined conversion matrices.

13. A color image signal processing apparatus according to claim 12, wherein said conversion means comprises a memory which is addressed by the color image signal received by said input means and operation means for converting the characteristics of the color image signal according to said one predetermined conversion matrix by utilizing outputs from said memory.

14. A color image signal processing apparatus according to claim 10, wherein said conversion means is adapted to convert the characteristics of the color image signal received by said input means according to said predetermined conversion parameters in order to compensate for any differences between the spectral characteristics of said plural kinds of color input devices.