Two-dimensional colorimeter, and spectral sensitivity correcting method

Abstract

A two-dimensional colorimeter includes: an image sensing section, having an image sensor constituted of a number of pixels arranged in a two-dimensional manner, for sensing an object image to be measured to acquire a two-dimensional image; a discriminator for discriminating whether a targeted color with respect to the two-dimensional image acquired by the image sensing section is to be corrected in terms of a pixel or pixels; and a calculator for performing a calculation to apply predetermined correction information corresponding to the color to be corrected to the two-dimensional image in terms of a pixel or pixels, based on a discrimination result by the discriminator.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a block diagram showing an example of a two-dimensional colorimeter embodying the invention.

FIG. 2 is a block diagram for describing an example of an internal configuration of a digital computation processor in the two-dimensional calorimeter, and a flow on image data processing concerning an arbitrary correction.

FIG. 3 is a chart showing an example of an arbitrary calibration coefficient lookup table.

FIG. 4 is a conceptual diagram of a two-dimensional image for describing an arbitrary correction technique in the embodiment.

FIG. 5 is a flowchart showing an example of an operation concerning the arbitrary correction to be executed by the two-dimensional colorimeter in the embodiment.

FIG. 6 is a flowchart showing an example of a white color calibration in Step S5 of the flowchart shown in FIG. 5.

FIG. 7 is a flowchart showing an example of an arbitrary correction in Step S6 of the flowchart shown in FIG. 5.

FIG. 8 is a flowchart showing an operation to be executed in the case where the arbitrary correction is executed by an external device.

FIG. 9 is a flowchart showing an example of a white color calibration in Step S14 of the flowchart shown in FIG. 8.

FIG. 10 is a flowchart showing an example of an arbitrary correction in Step S15 of the flowchart shown in FIG. 8.

FIGS. 11A through 11D are diagrams for describing a conventional arbitrary correction, wherein FIG. 11A is a diagram showing a certain two-dimensional image, and object sensing areas concerning colors A, B, and C within the two-dimensional image, FIG. 11B is a diagram showing a state that measurements values with respect to the object sensing areas concerning the colors A, B, and C have a measurement error, FIG. 11C is a diagram showing a state that calibration concerning a white color W is performed with respect to the two-dimensional image, and FIG. 11D shows states describing that measurement errors occur with respect to the other two colors, despite that correction is performed with respect to one of the colors A, B, C.

FIG. 12 is a diagram for describing an arbitrary correction method, and an arbitrary calibration coefficient calculation technique according to the conventional art.

Claims

1. A two-dimensional colorimeter comprising: an image sensing section, including an image sensor constituted of a number of pixels arranged in a two-dimensional manner, for sensing an object image to be measured to acquire a two-dimensional image;a discriminator for discriminating whether a targeted color with respect to the two-dimensional image acquired by the image sensing section is to be corrected in terms of a pixel or pixels; anda calculator for performing a calculation to apply predetermined correction information corresponding to the color to be corrected to the two-dimensional image in terms of a pixel or pixels, based on a discrimination result by the discriminator.

2. The two-dimensional colorimeter according to claim 1, further comprising: a storage for storing discrimination chromaticity values for discriminating whether the targeted color is the color to be corrected, and calibration coefficients as the correction information in association with the discrimination chromaticity values, whereinthe discriminator compares measurement chromaticity values as chromaticity values on the two-dimensional image acquired by the image sensing section in terms of a pixel or pixels, with the discrimination chromaticity values stored in the storage, andthe calculator selects the calibration coefficient corresponding to the color to be corrected from the calibration coefficients stored in the storage in accordance with a comparison result by the discriminator to multiply the selected calibration coefficient by the measurement chromaticity value.

3. The two-dimensional colorimeter according to claim 2, wherein the discrimination chromaticity values are information relating to chromaticity ranges each having a predetermined range concerning the chromaticity value.

4. The two-dimensional colorimeter according to claim 2, further comprising a calibrator for calculating the respective calibration coefficients based on a ratio of the measurement chromaticity value corresponding to the color to be corrected versus a true value obtained by a measurement with respect to the color to be corrected by a measuring device other than the two-dimensional colorimeter.

5. The two-dimensional colorimeter according to claim 2, wherein the storage stores therein a lookup table recorded with chromaticity range information and the correction information which are correlated to each other with respect to each of the colors to be corrected.

6. The two-dimensional colorimeter according to claim 5, wherein the lookup table is created by a calibrator, andthe calibrator creates the lookup table based on information relating to the color to be corrected at a site arbitrarily designated by a user on the two-dimensional image acquired by sensing the object image to be measured, and based on the measurement chromaticity value and a true value at the site designated on the two-dimensional image.

7. The two-dimensional colorimeter according to claim 1, wherein a white color calibration is performed as a process prior to the calculation of applying the predetermined correction information corresponding to the color to be corrected to the two-dimensional image in terms of a pixel or pixels.

8. A spectral sensitivity correcting method comprising steps of sensing an object image to be measured to acquire a two-dimensional image;discriminating whether a targeted color with respect to the two-dimensional image acquired in the sensing step is to be corrected in terms of a pixel or pixels; andperforming a calculation to apply predetermined correction information corresponding to the color to be corrected to the two-dimensional image in terms of a pixel or pixels, based on a discrimination result in the discriminating step.

9. The spectral sensitivity correcting method according to claim 8, further comprising: a step of storing discrimination chromaticity values for discriminating whether the targeted color is the color to be corrected, and calibration coefficients as the correction information in association with the discrimination chromaticity values, whereinin the discriminating step, a comparison is made between measurement chromaticity values as chromaticity values on the two-dimensional image acquired in the sensing step in terms of a pixel or pixels, and the discrimination chromaticity values stored in the storing step, andin the calculating step, the calibration coefficient corresponding to the color to be corrected is selected from the calibration coefficients stored in the storing step in accordance with a comparison result in the discriminating step to multiply the selected calibration coefficient by the measurement chromaticity value.

10. A two-dimensional colorimeter comprising: an image sensing section, including an image sensor constituted of a number of pixels arranged in a two-dimensional manner, for sensing an object image to be measured to acquire a two-dimensional color image;a discriminator for discriminating a measurement chromaticity value with respect to the two-dimensional color image acquired by the image sensing section in terms of a pixel or pixels; anda calculator for selecting a calibration coefficient corresponding to the discriminated measurement chromaticity value with respect to the two-dimensional color image in terms of a pixel or pixels to multiply the selected calibration coefficient by the discriminated measurement chromaticity value.