Method for collecting data for color measurements from a digital electronic image capturing device or system

• US 20060078199A1
• Filed: 08/11/2005
• Published: 04/13/2006
• Est. Priority Date: 05/13/2004
• Status: Active Grant

• Current Assignee: Color Savvy Systems Ltd.
• Original Assignee: Color Savvy Systems Ltd.
• Inventors: Seibert, Karl F., Bodnar, Gary N., Pearson, Christopher H., Duke, Ronald J., Broehl, Joshua M., Staufenberg, Donald J., Shova, Bryan M.
• Granted Patent: US 7,751,653 B2
• Time in Patent Office: Days
• US Class Current: 382/168
• CPC Class Codes: G01J 1/0233 Handheld
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0262 Constructional arrangements for removing stray light
• CPC Class Codes: G01J 3/027 Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/0289 Field-of-view determination; Aiming or pointing of a spectrometer; Adjusting alignment; Encoding angular position; Size of measurement area; Position tracking
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/50 using electric radiation detectors
• CPC Class Codes: G01J 3/524 Calibration of colorimeters
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation

Abstract

A method for providing an intensity or brightness measurement using a digital image-capturing device comprising: selecting a target area within a field of view of the image-capturing device, the target area containing pixels; determining the brightness of pixels in the target area; accumulating the brightness values of the pixels in the target area; and determining a pixel value representative of the pixels in the target area. A device for making color measurements comprising an image-capture device, a processor or logic device, and a memory location for accumulating color data, and the processor or logic device is programmed to perform color measurements by accumulating the data for pixels located in the target area in memory, and determining a representative color value.

Claims

1. A method for providing a color measurement using a digital image-capturing device comprising:

selecting a target area within a field of view of the image-capturing device, the target area containing pixels,

generating brightness values for at least the pixels in the target area,

accumulating the brightness values of the pixels in the target area; and

determining a pixel value representative of the brightness of the pixels in the target area.

2. The method of claim 1 wherein the representative pixel value is an average value.

3. The method of claim 1 wherein the representative pixel value is a median pixel value.

4. The method of claim 1 wherein the target area contains three or more color-selective pixel types and the step of accumulating the brightness values includes individually accumulating brightness values for each of the pixel types and the step of determining a representative pixel value includes determining a representative pixel value for each pixel type.

5. The method of claim 4 wherein the pixel types include red, green and blue pixels.

6. The method of claim 4 wherein the step of accumulating the brightness values includes accumulating the brightness values for multiple image frames.

7. The method of claim 6 wherein the region of interest is at least 2×

2 pixels.

8. The method of claim 7 wherein the number of image frames is at least 3.

9. The method of claim 1 wherein the image-capturing device is a digital camera or an image-capturing chip.

10. The method of claim 9 wherein the image-capturing device includes a gain and the method includes the step of setting the gain to a level sufficient to reduce noise but high enough that the device is below saturation when presented with the brightest possible image.

11. The method of claim 9 wherein the image-capturing device includes a shutter width and the method includes the step of setting the shutter width to the highest possible value, but just below the value at which any pixel saturates when presented with the brightest possible image.

12. The method of claim 9 wherein the image-capturing device includes a focus and the method includes the step of blurring the image to mask imperfections but permit good recognition of the target color.

13. The method of claim 8 wherein the image-capturing device is a CMOS imaging chip.

14. The method of claim 1 wherein the method includes the steps of writing the brightness values of the pixels in at least a portion of the field of view into memory locations.

15. The method of claim 14 wherein the step of writing the pixel values into memory is performed using a first logic device and the steps of accumulating the intensity or brightness values of the pixels and determining a pixel value representative of the intensity or brightness of the pixels is performed by a second logic device or devices different than the first logic device.

16. The method of claim 15 wherein the first logic device is a data collection circuit and the second logic device is a data processing circuit.

17. A device for making color measurements comprising an image-capture device, a processor or logic device, and a memory location for accumulating color data, wherein the processor or logic device is programmed to perform color measurements by identifying pixels in a target area, accumulating the brightness values for the pixels located in the target area in memory, and determining a representative color value.

18. The device of claim 17 wherein the logic device includes a first logic device(s) for writing at least R, G, B pixel values from the target area into memory and a second logic device(s) for accumulating the pixel values and determining a representative color value.

19. A device for measuring the color of a target area in an image comprising:

a housing including an image-capture device,

a processor or logic device,

a memory location, and

a platen having an aperture therein through which the color measurement is made,

the housing being mounted to reciprocate with respect to the platen such that in a first position the housing is spaced from the platen and in the second position the housing encloses the aperture in the platen to provide a light-tight seal for the aperture.

20. The device of claim 19 wherein by closing the housing about the aperture, the image-capture device captures an image of the aperture from which the color measurement is made.