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

• US 20060078225A1
• Filed: 05/13/2005
• 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., Pearson, Christopher H., Duke, Ronald J., Bodnar, Gary
• Granted Patent: US 7,599,559 B2
• Time in Patent Office: Days
• US Class Current: 382/286
• 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 3/0272 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; measuring the intensity or brightness of pixels in a target area; accumulating the intensity or brightness values of the pixels in the target area; and determining a pixel value representative of the intensity or brightness 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 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,

measuring the intensity or brightness of pixels in a target area,

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

determining a pixel value representative of the intensity or 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 intensity or brightness values includes individually accumulating intensity or 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 respectively.

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

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

2 pixels and up to 100×

100 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. A device for measuring the color of a target area comprising:

a housing and an image-capturing device having a focal plane,

the housing having a first surface having an aperture therein defining a target plane through which the color measurement is made,

the surface and the housing providing a stable, fixed parallel orientation of the focal plane of the image-capturing device relative to the target plane.

15. The device of claim 14 wherein the first surface includes a contact surface that surrounds the aperture and has sufficient area that a light-tight seal is formed between the target area and the contact surface.

16. The device of claim 15 wherein the first surface also includes a recessed area, inset from the target area such that the measurement device does not contact the target area in the immediate vicinity of the aperture and the contact surface forms a light-tight contact surrounding the target area.

17. The device of claim 15 wherein, but for the aperture, the housing is light-tight and the housing includes at least one light source for making color measurements of the target area through the aperture.

18. The device of claim 17 wherein the image-capturing device is a CMOS imaging chip.

19. The device of claim 18 wherein the device fits in the palm of the hand.

20. The device of claim 14 wherein the device includes 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 in the target area and determining a representative color value.

21. 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.

22. The device of claim 21 wherein the processor or logic device is programmed to perform the steps of:

measuring the brightness of pixels in a 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 a the target area.