Characterizing optical system performance with color camera device

Abstract

An apparatus, system, and method are provided for processing an output of a color camera device such that the color camera device can be used to measure color consistency and resolution of an optical system. The processing includes converting an output of the color camera to an XYZ color space using a conversion matrix. A conversion matrix is generated by capturing color images of light of three different wavelength ranges and colorimeter measurements. The processing further includes overcoming the demosaicing effect of the color camera to measure the resolution of the optical system using the optical test target displayed by the optical system. The optical test target has a consistent appearance in the direction of uniformity. A resolution is determined based on a one-dimensional image generated by performing a mathematical operation in a direction of uniformity.

Description

[0001] Related Applications

[0002] This application claims the benefit of 63 / 439,287, filed on January 17, 2023. 63 / 439,287 is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure generally relates to color imaging, and more particularly, to characterizing the performance of an optical system using a color imaging device. Background Art

[0004] Analyzing an optical system typically includes characterizing color consistency and resolution. However, to characterize the resolution of an optical system, the measurement system typically needs to have a higher resolution than the optical system being measured. Additionally, to accurately measure the color consistency of an optical system, the measurement system typically needs to output the measurement results of the color consistency of the XYZ values in the CIE1931 color space. The XYZ values from the CIE1931 color space are commonly used as a standard for quantifying and communicating colors. To output the XYZ values, most measurement systems use imaging colorimeters.

[0005] Near-eye displays are often used in applications such as virtual reality (VR) or augmented reality (AR) head-mounted headsets. An eye motion box (EMB) refers to a defined space or volume within which a user's eyes can move while still being able to clearly see the images generated by a near-eye display (NED) system. The EMB determines the range of natural eye movements allowed without loss of clarity or focus of the displayed images. If the EMB is too small, the user may often find that parts of the image become blurred or leave the field of view, which can be uncomfortable and disrupt the immersive experience. Therefore, measuring and optimizing the EMB is important for ensuring a comfortable and effective viewing experience for the user. Summary of the Invention

[0006] Contrary to using a standard imaging colorimeter, preferably, a simple off-the-shelf "conventional" color imaging device is used to measure the color consistency and resolution of an optical system.

[0007] The problem with using a standard imaging colorimeter to measure the properties of an EMB (eye motion box) is the size of the colorimeter. Imaging colorimeters are typically too large to easily scan the different positions of the EMB of the WG (waveguide) of an NED (near-eye display) system.

[0008] The problem with using a standard color imaging device to measure optical properties is that the color imaging device uses a demosaic algorithm (also known as the deBayering effect) to generate a color image. The demosaic is applied to the image captured by the imaging device using a Bayer filter on the image sensor (i.e., a grid of red, green, and blue filters). Each sensor pixel captures light from only one primary color, so the raw image data contains incomplete color information. The demosaic algorithm then interpolates the missing color for each pixel by analyzing adjacent pixels, effectively reconstructing a full-color image. The demosaic process of image interpolation in the imaging device reduces the resolution of the imaging device.

[0009] The present disclosure provides devices, systems, and methods for processing the output of an off-the-shelf color imaging device such that the color imaging device can be used to measure color consistency and resolution of an optical system.

[0010] In one embodiment, the present disclosure provides devices, systems, and methods for converting the output of an imaging device to the XYZ color space using a conversion matrix generated by comparing the output of the imaging device for light in at least three different wavelength ranges with the output of a colorimeter.

[0011] In another embodiment, the present disclosure provides devices, systems, and methods for overcoming the demosaic of a color imaging device such that the color imaging device can be used to measure the resolution of an optical system by using the raw green channel image of an optical test target from the color imaging device and performing a mathematical operation along the direction of uniformity of the optical test target.

[0012] Although multiple features are described herein with respect to embodiments of the invention; the features described with respect to a given embodiment may also be combined with other embodiments. The following description and drawings set forth certain illustrative embodiments of the invention. However, these embodiments merely indicate several of the various ways in which the principles of the invention may be employed. Other objects, advantages, and novel features of aspects of the invention will become apparent from the following detailed description when considered in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings, which are not necessarily to scale, illustrate aspects of the invention, wherein like reference numerals are used to indicate the same or similar parts in the various views.

[0014] Figure 1 is an exemplary block diagram of a measurement system for measuring optical properties of an optical system.

[0015] Figure 2An exemplary block diagram of a processor circuitry that receives outputs of a color imaging device and a colorimeter based on light emitted by a light source.

[0016] Figure 3 An exemplary block diagram of red, green, and blue pixels in a color imaging device.

[0017] Figure 4 Depicts an exemplary optical test target.

[0018] Figure 5 Depicts Figure 4 An exemplary original green test image of the optical test target.

[0019] Figure 6 Depicts Figure 5 An exemplary test one - dimensional image of the exemplary original green test image.

[0020] Figure 7 Depicts an exemplary original green test image of a cross - shaped test target.

[0021] The present invention will be described in detail below with reference to the accompanying drawings. In the drawings, each element with a reference numeral is similar to other elements with the same reference numeral, regardless of any letter designations following the reference numeral. In the text, a reference numeral with a specific letter designation following the reference numeral refers to a specific element with both a number and a letter designation, and a reference numeral without a specific letter designation refers to all elements with the same reference numeral, regardless of any letter designations following the reference numeral in the drawings. Detailed Description of the Invention

[0022] The present disclosure provides devices, systems, and methods for processing the output of an off-the-shelf color imaging device such that the color imaging device can be used to measure the color consistency and resolution of an optical system. The processing includes: converting the output of the imaging device from one color space (e.g., RGB) to the XYZ color space using a conversion matrix. The conversion matrix is generated by capturing color images of light in three different wavelength ranges. A colorimeter is also used to measure light in three different wavelength ranges in the XYZ color space. The outputs of the colorimeter and the color imaging device for light in the three wavelength ranges are compared to generate a conversion matrix for converting from the color space of the imaging device to the XYZ color space. The output of the color imaging device is then multiplied by the conversion matrix to convert to the XYZ color space. The processing further includes: overcoming the demosaicing effect of the color imaging device to measure the resolution of the optical system. To measure the resolution of the optical system, the color imaging device captures an image of an optical test target displayed by the optical system. The optical test target has a pattern of known contrast structure with a known pitch such that the optical test target has a uniform appearance along the direction of uniformity; a one-dimensional image is generated by performing a mathematical operation (e.g., summing, averaging, convolution, etc.) along the direction of uniformity of the optical test target. The resolution of the optical system is then determined based on the known pitch of the contrast structure of the test one-dimensional image and the optical test target.

[0023] Turning Figure 1 , shows a measurement system 10 for measuring the optical properties of an optical system 12 using an optical test target 14 ( Figure 4 ) and a light source 16. The measurement system 10 includes a color imaging device 20, a colorimeter 24, and a computer device 30.

[0024] As described in further detail below, the computer device 30 uses the light source 16 and based on the output of the colorimeter 24, converts the output of the color imaging device 20 to the XYZ color space. The computer device 30 also measures the resolution of the optical system 12 based on an image generated by the color imaging device 20 that images the optical system 12 displaying the optical test target 14. The computer device 30 includes processor circuitry 32 for performing these tasks.

[0025] Turning Figure 2, when converting the output of the color imaging device 20 to the XYZ color space, the processor circuitry 32 determines the colorimeter output 34 and the imaging device output 36 of the light in three wavelength ranges. Three different wavelength ranges of light can be used because the XYZ color space (also known as tristimulus photometry) is additive. For example, when both red light and blue light are displayed, the XYZ values are equal to the linear sum of two separate sources (i.e., red light and blue light). Due to this additivity, each color can be represented by a linear vector with three elements. For example, red light can be represented as [1; 0; 0], green light can be represented as [0; 1; 0], and blue light can be represented as [0; 0; 1], while white light is represented as [1; 1; 1]. By using three different wavelength ranges of light (e.g., red light, green light, and blue light), the XYZ values can be measured by the colorimeter 24 and compared with the output of the color imaging device 20.

[0026] The three different wavelength ranges can be referred to as three different colors. Each of the three different colors can be a Gaussian distribution of wavelengths distributed around a dominant wavelength (also known as the central wavelength). These three different colors can match the three colors (i.e., dimensions) of the color space of the color imaging device. The optical system can also include a light emitter that outputs three colors (i.e., light in wavelength ranges). These three different colors can match the colors of the light emitter of the optical system.

[0027] In one embodiment, the light source can be the light emitter of the optical system. That is, the color imaging device and the colorimeter can measure the output of the light emitter of the optical system.

[0028] In another embodiment, the light source can be a device separate from the light emitter of the optical system, but the light source can have output properties similar to those of the light emitter of the optical system (e.g., wavelength range, intensity, etc.). The separate light source can have the same light emission properties as the light emitter of the optical system.

[0029] For each of the three wavelength ranges, when the light source 16 emits light 38 having that wavelength, the processor circuitry 32 receives the colorimeter output 34 from the colorimeter 24 based on the measurement of the light source 16. That is, the light source 16 emits light 38 having that wavelength, the colorimeter 24 measures the emitted light 38 having that wavelength, and the processor circuitry 32 receives the colorimeter output 34 of the measurement result. Similarly, for each of the three wavelength ranges, the processor circuitry 32 also receives the imaging device output 36 from the imaging device 20 based on the imaging of the emitted light 38 having that wavelength. That is, the light source 16 emits light 38 having that wavelength, the imaging device 20 images the emitted light 38 having that wavelength, and the processor circuitry 32 receives the imaging device output 36 of the imaging.

[0030] As described above, the chromometer output and the imaging device output are in different color spaces. That is, when the chromometer output is in the XYZ color space, the imaging device output is in an imaging device color space different from the XYZ color space. The chromometer 24 can be any suitable device for outputting the measurement result of incident light in the XYZ color space. For example, the chromometer can be a point chromometer that outputs a single XYZ value of incident light. In this way, the present disclosure can utilize a point chromometer instead of using an imaging chromometer (outputting an array of measurement values of a scene) as described above.

[0031] In one embodiment, the imaging device color space can be in the RGB (red, green, blue) color space. For example, the output of the imaging device can include an array of pixels. For each pixel of the array of pixels, the imaging device output can include a red value, a green value, and a blue value, such that each pixel in the array of pixels represents a vector formed by the red value, the green value, and the blue value.

[0032] The color imaging device 20 can be any suitable device for outputting an image including an array of pixels in an additive color space (e.g., RGB). That is, the color imaging device 20 can include various configurations and components. For example, the color imaging device 20 can include an image sensor (e.g., a CCD or CMOS sensor), a digital signal processor (DSP), a lens assembly, and an integrated circuit for image processing. The color imaging device 20 can also include auxiliary hardware, such as an autofocus mechanism, an optical image stabilization module, a memory (e.g., an embedded memory, a removable storage medium, etc.).

[0033] In addition to the imaging device color space being in the RGB color space, the three wavelength ranges of the light emitted by the light source 16 can also include red, green, and blue. For example, the light of the three wavelength ranges can be emitted separately (i.e., at different times) such that the measurement and imaging of the first wavelength (e.g., red light), the second wavelength (e.g., green light), and the third wavelength (e.g., blue light) by the chromometer and the imaging device occur at different non-overlapping times. In this way, the red light, the green light, and the blue light can be imaged by the color imaging device 20 and measured separately by the chromometer 24, such that the imaging device output 36 and the chromometer output 34 are known for each dimension (e.g., R, G, and B) of the imaging device color space.

[0034] The light source 16 can be any suitable structure for emitting light. For example, the light source 16 can include one or more light emitting diodes (LEDs), organic light emitting diodes (OLEDs), micro LEDs, laser diodes, mini LEDs, quantum dot (QD) conversion, phosphor conversion, excimer lamps, multi - photon combinations, or SLM wavefront manipulation. The light source 16 can include additional components (e.g., a color wheel) for modifying the wavelength of the emitted light. For example, the light source 16 can be a display, a waveguide, etc.

[0035] Continuing with the above example in the RGB color space, the camera device output 36 for light of the red wavelength can be represented as [R r ; G r ; B r T and the camera device output for light of the green wavelength is represented as [R g ; G g ; B g T and the camera device output for light of the blue wavelength is represented as [R b ; G b ; B b T . Similarly, the colorimeter output for light of the red wavelength can be represented as [X r ; Y r ; Z r T and the colorimeter output for light of the green wavelength is represented as [X g ; Y g ; Z g T and the colorimeter output for light of the blue wavelength is represented as [X b ; Y b ; Z b T .

[0036] The processor circuitry 32 generates a colorimeter matrix (M xyz ) by combining the colorimeter outputs 34 for three wavelength ranges such that the colorimeter outputs 34 for each of the three wavelength ranges form the columns of the matrix. Similarly, the processor circuitry 32 generates a camera device matrix (M camera ) by combining the camera device outputs 36 for three wavelength ranges such that the camera device outputs 36 for each of the three wavelength ranges form the columns of the matrix.

[0037] ​​​​​​Continuing with the above example of RGB emitted light and RGB color space, the camera matrix and colorimeter matrix can be defined as follows:

[0038]

[0039] Processor circuitry 32 uses M xyz and M camera To do this, the processor circuitry converts the output of the camera device into the XYZ color space as shown below. xyz Multiply by M camera The inverse of the transformation matrix (M conversion ):

[0040] Mconversion=Mxyz*Mcamera -1

[0041] The processor circuitry 32 receives the camera output 36 and processes the M conversion The output 36 of the camera is applied to generate a transformed output 40 to use M conversion By adding M conversion Applied to the camera output 36 , the converted output 40 is in the XYZ color space. The processor circuitry 32 also outputs the converted output 40 .

[0042] In one embodiment, the output of the camera is an image comprising an array of pixels. This can be done by multiplying each pixel in the array by M. conversion , M conversion 36 applied to the output of the camera. Alternatively, instead of converting each pixel of the camera output, the processor circuit system 32 may group each of the pixels into blocks of pixels. Each block of pixels may be a group of adjacent pixels (e.g., 10 x 10 pixels, 100 x 100 pixels, etc.). For each of the blocks of pixels, the processor circuit system 32 may calculate a red value, a green value, and a blue value based on an average of the red values, green values, and blue values ​​of the pixels in the block of pixels. The processor circuit system 32 may then calculate the red value, the green value, and the blue value by multiplying the vector of the red value, the green value, and the blue value of each block of pixels by M. conversion , M conversion Applicable to the output of the camera device.

[0043] Steering Figure 3 , Figure 4 and Figure 5, when measuring the resolution of the optical system 12, the processor circuitry 32 receives the raw image 50 from the color imaging device 20. The raw image 50 is an image of the optical system 12 that displays the optical test target 14. The raw image includes green image data 52. The green image data 52 is analyzed to determine the resolution of the optical system 12. That is, the green image data 52 replaces the monochromatic image.

[0044] The color imaging device 20 can be a Bayer-based color imaging device 20. As Figure 3 shown, the raw image 50 can include an array 54 of pixels having different color sensitivities. The pixel array 54 can have a checkerboard structure, where there are primarily green pixels (G1, G3, G5, G7, G9, G11, G13, G15, G17, G19, G21, G23, G25), which are mixed with a combination of red pixels (R2, R4, R12, R14, R22, R24) and blue pixels (B6, B8, B10, B16, B18, B20).

[0045] As an example, a monochromatic image from the color imaging device 20 is not used because, in the monochromatic grayscale mode, the grayscale value of each pixel is a linear combination of the RGB values of each pixel according to the photopic weights. This linear combination of the RGB values causes the image to be smoothed in the monochromatic mode because the value of each pixel overlaps with its nearest and next-nearest neighboring pixels. This linear combination may reduce the resolution of the monochromatic image. For this reason, the processor circuitry 32 uses the green image data 52 instead of the monochromatic image output by the color imaging device 20. The green image data 52 (i.e., not the red image data and the blue image data) can be used because the photopic curve of the human eye is similar to the photopic curve of the green pixels.

[0046] As described above, the raw image 50 is an image of the optical system 12 that displays the optical test target 14. The optical test target 14 is displayed by the optical test target 14 because the optical test target has a pattern of known contrast structures 60 with known spacings 62 such that the optical test target 14 has a uniform appearance along the direction of uniformity 64. These known properties of the optical test target 14 and the direction of uniformity 64 are used to calculate the resolution of the optical system 12.

[0047] In one embodiment, as Figure 4 shown, the optical test target 14 can be a Ronchi ruling. In this example, the direction of uniformity 64 is vertical. However, the direction of uniformity 64 can be horizontal, vertical, or any suitable direction.

[0048] The processor circuitry 32 separates the green image data into a raw green test image 56 with pixels 54. For example, the green image data can be separated by varying the gain of the color imaging device such that the outputs of the red and blue pixels are zero. Figure 5 depicts Figure 4 the raw green test image 56 of the optical test target 14 shown. As Figure 3 shown, the raw green test image 56 has a checkerboard appearance where the black pixels represent the red and blue pixels.

[0049] The processor circuitry 32 generates a test one-dimensional image 66 based on a mathematical operation performed on the raw green test image 56 along the direction of uniformity 64. The mathematical operation can include at least one of convolution, summation, or averaging. For example, Figure 6 shows a one-dimensional image 66 generated by summing the raw green test image 56 along the vertical direction (i.e., the direction of uniformity 64).

[0050] In one embodiment, the mathematical operation can include: convolution along the direction of uniformity using an array having an orientation matching the direction of uniformity. For example, when the direction of uniformity is horizontal, the array can be a horizontal array having a horizontal orientation. Similarly, when the direction of uniformity is vertical, the array can be a vertical array having a vertical orientation.

[0051] The processor circuitry 32 determines and outputs 68 the resolution of the optical system 12 along the direction of uniformity 64 based on the known pitch 62 of the contrast structure 60 of the test one-dimensional image 66 and the optical test target 14. For example, when the contrast structure 60 is distinguishable in the test one-dimensional image 66, it can be determined that the optical system 12 has a resolution of at least matching the known pitch 62 of the optical test target 14. Similarly, when the contrast structure 60 is not distinguishable in the test one-dimensional image, it can be determined that the optical system 12 has a resolution less than the known pitch 62.

[0052] For example, when an optical test target 14 with a known pitch 62 of 1 mm along the horizontal direction is displayed, if adjacent contrast structures 60 are distinguishable in the test one-dimensional image 66, it can be determined that the optical system 12 has a resolution of at least 1 mm. Conversely, if adjacent contrast structures 60 are not distinguishable in the test one-dimensional image 66, it can be determined that the resolution of the optical system 12 along the horizontal dimension is less than 1 mm.

[0053] In another example, a single optical test target 14 can be used. The measured contrast of the contrast structure 60 in the test one-dimensional image of the optical test target 14 can be used to determine the resolution of the system. For example, it is known that a 20% contrast is associated with a specific resolution of the optical test target 14. Alternatively, the contrast of the optical test target 14 can be used as a measure of the resolution of the optical system.

[0054] When the contrast between the contrast structures 60 is greater than the minimum detection threshold, it can be determined that the contrast structures 60 are distinguishable. For example, the contrast between the contrast structures 60 in the test one-dimensional image 66 can be determined based on the maximum and minimum values of the test one-dimensional image 66. As an example, the average maximum value of the test one-dimensional image 66 (e.g., Figure 6 the average of the peaks of the sine structure shown) can be determined, and the average minimum value of the test one-dimensional image 66 (e.g., Figure 6 the average of the valleys of the sine structure shown) can be determined. The contrast can be determined based on the difference between the maximum value and the minimum value.

[0055] The processor circuitry 32 can determine the vertical resolution and the horizontal resolution of the optical system 12 by performing the above process twice. Once the optical system displays an optical test pattern in a direction 64 with horizontal uniformity (i.e., to determine the horizontal resolution), and once the optical system displays an optical test pattern in a direction 64 with vertical uniformity (i.e., to determine the vertical resolution).

[0056] Alternatively, a cross-shaped optical test target can be used as shown in Figure 7 instead of measuring the vertical resolution and the horizontal resolution separately. Figure 7 An original green test image of the cross-shaped optical test target is depicted. At the bottom and left side of the original green test image, test one-dimensional images representing the sum of the vertical direction and the horizontal direction are shown. As shown, the imaging device only grabs half of the pixels (i.e., only green pixels), however, the resolution of the imaging device is not impaired, and the summed 1D curve is not affected. By measuring the width of the cross, the line spread function of the system and the modulation transfer function (MTF) of the system can be analyzed (i.e., by performing a Fourier transform of the line spread function of the optical system).

[0057] The processor circuitry 32 can output the determined resolution and the converted output in any suitable manner. For example, the processor circuitry 32 can output the data by storing the data in a memory, sending the data via a network interface, displaying the data on a display, etc.

[0058] The computer device 30 can include a range of configurations and designs. For example, the computer 10 can be implemented as a single device, such as a server, desktop computer, laptop computer, or other standalone unit. These single devices can incorporate basic components such as a central processing unit (CPU), memory modules (including random-access memory (RAM) and read-only memory (ROM)), storage devices (such as solid-state drives or hard disk drives), and various input / output (I / O) interfaces. Alternatively, the computer device 30 can consist of a network of interconnected computer devices, thereby forming a more complex and integrated system. This may include server clusters, distributed computing environments, or cloud-based infrastructures, where multiple devices are linked via network interfaces to work in coordination, thus generally enhancing processing power, data storage, and redundancy.

[0059] The processor circuitry 32 can have various implementations. For example, the processor circuitry 32 can include any suitable device, such as a processor (e.g., CPU), programmable circuitry, integrated circuits, memory and I / O circuits, application-specific integrated circuits, microcontrollers, complex programmable logic devices, other programmable circuitry, etc. The processor circuitry 32 can also include non-transitory computer-readable media, such as random-access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), or any other suitable media. Instructions for performing the methods described below can be stored in the non-transitory computer-readable media and executed by the processor circuitry 32. The processor circuitry 32 can be communicatively coupled to the computer-readable media and the network interface via a system bus, motherboard, or using any other suitable structure known in the art.

[0060] All ranges and ratio limitations disclosed in the specification and claims can be combined in any manner. Unless otherwise clearly stated, references to "a", "an", and / or "the" can include one or more than one, and references to singular items can also include plural items.

[0061] Although the present invention has been shown and described with reference to specific or multiple embodiments, equivalent changes and modifications will occur to other technicians in the art after reading and understanding this specification and the drawings. In particular, with respect to the various functions performed by the above-described elements (components, assemblies, devices, compositions, etc.), unless otherwise indicated, the terms used to describe such elements (including references to "means") are intended to correspond to any element that performs the specified function of the element (i.e., functionally equivalent), even if structurally not equivalent to the disclosed structure that performs the function in one or more exemplary embodiments of the present invention shown herein. Moreover, although the present invention may be described with respect to only one or more implementations of several illustrated embodiments, such features may be combined with one or more other features of other embodiments that may be desirable and advantageous for any given or particular application.

Claims

1. A computer apparatus for measuring optical properties of an optical system based on an output of a colorimeter, an optical test target, and from an image generated by a color camera using a light source, the computer apparatus comprising processor circuitry configured to: The output of the color camera is converted into an XYZ color space based on the output of the colorimeter by: For each of the three wavelength ranges, the colorimeter output and the camera output of the light of the three wavelength ranges are determined by the following operations: When the light source emits light having the wavelength, receiving a colorimeter output from the colorimeter based on a measurement result of the light source, wherein: The colorimeter output is in the XYZ color space; receiving a camera output from the camera based on imaging of the light source when the light source emits light having the wavelength, wherein the camera output is in a camera color space different from the XYZ color space; A colorimeter matrix (M) is generated by combining the colorimeter outputs of the three wavelength ranges. xyz ), such that the colorimeter output for each of the three wavelength ranges forms a column of the matrix; By combining the camera outputs of the three wavelength ranges, a camera matrix (M camera ), so that the camera outputs of each wavelength range in the three wavelength ranges form columns of the matrix; By using M xyz Multiply by M camera The inverse of the transformation matrix (M conversion ); receiving an output of the camera device; By using M conversion applied to the output of the camera to generate a converted output such that the converted output is in the XYZ color space; and outputting the converted output; as well as The resolution of the optical system displaying the optical test target is measured by: receiving a raw image from the color camera of the optical system displaying the optical test target, wherein: The original image includes green image data; The optical test target has a pattern of known contrast structures having known spacings such that the optical test target has a consistent appearance along a direction of uniformity; separating the green image data into an original green test image comprising pixels; generating a test one-dimensional image based on a mathematical operation performed on the original green test image along the direction of the uniformity; determining a resolution of the optical system along the direction of the uniformity based on the test one-dimensional image and the known spacing of the contrast structures of the optical test target; and Outputs the determined resolution.

2. The computer device according to claim 1, wherein: The light source is part of the optical system being measured.

3. A computer apparatus for converting the output of a color camera to an XYZ color space based on the output of a colorimeter and using a light source, the computer apparatus comprising processor circuitry configured to: For each of the three wavelength ranges, the colorimeter output and the camera output of the light of the three wavelength ranges are determined by the following operations: When the light source emits light having the wavelength, receiving a colorimeter output from the colorimeter based on a measurement result of the light source, wherein: The colorimeter output is in the XYZ color space; receiving a camera output from the camera based on imaging of the light source when the light source emits light having the wavelength, wherein the camera output is in a camera color space different from the XYZ color space; A colorimeter matrix (M) is generated by combining the colorimeter outputs of the three wavelength ranges. xyz ), such that the colorimeter output for each of the three wavelength ranges forms a column of the matrix; By combining the camera outputs of the three wavelength ranges, a camera matrix (M camera ), so that the camera outputs of each wavelength range in the three wavelength ranges form columns of the matrix; By using M xyz Multiply by M camera The inverse of the transformation matrix (M conversion ); receiving an output of the camera device; By using M conversion applied to the output of the camera to generate a converted output such that the converted output is in the XYZ color space; and The converted output is output.

4. A computer device according to claim 3 or any one of the preceding claims, wherein: The camera color space is a red, green, and blue (RGB) color space.

5. A computer device according to claim 3 or any one of the preceding claims, wherein: The output of the camera device comprises an array of pixels; Each pixel in the array of pixels comprises a red value, a green value, and a blue value, such that each pixel in the array of pixels represents a vector formed by the red value, the green value, and the blue value.

6. The computer device according to claim 5, wherein: By multiplying each pixel in the array of pixels by M conversion , M conversion Applied to the output of the camera device.

7. The computer device of claim 5, wherein: The processor circuitry is further configured to: grouping each of the pixels into a pixel block including a set of adjacent pixels; as well as For each pixel block in the pixel blocks, a red value, a green value, and a blue value are calculated based on the average of the red values, green values, and blue values ​​of the pixels in the pixel block; by multiplying the vector of the red value, the green value, and the blue value of each pixel block by M conversion , M conversion Applied to the output of the camera device.

8. A computer device according to claim 3 or any one of the preceding claims, wherein: The three wavelength ranges of light include red, green and blue.

9. The computer device of claim 8, wherein: The image pickup device output of the red wavelength light is [R r ; G r ; B r ] T ; The image pickup device output of the green wavelength light is [R g ; G g ; B g ] T ; The camera output of the blue wavelength light is [R b ; G b ; B b ] T ; The colorimeter output of the red wavelength light is [X r ; Y r ; Z r ] T ; The colorimeter output of the green wavelength light is [X g ; Y g ; Z g ] T ; The colorimeter output of the blue wavelength light is [X b ; Y b ; Z b ] T ; as well as 10. A computer device according to claim 3 or any one of the preceding claims, wherein: The colorimeter is a point colorimeter.

11. A computer device according to claim 3 or any one of the preceding claims, wherein: Light in the three wavelength ranges is emitted separately, so that imaging of the first wavelength using the colorimeter and the camera device, imaging of the second wavelength using the colorimeter and the camera device, and imaging of the third wavelength using the colorimeter and the camera device occur at different non-overlapping times.

12. A computer apparatus for measuring a resolution of an optical system from an image generated by a color camera that captures an image of the optical system showing an optical test target, the computer apparatus comprising processor circuitry configured to: receiving a raw image from the color camera of the optical system displaying the optical test target, wherein: The original image includes green image data; The optical test target has a pattern of known contrast structures having known spacings such that the optical test target has a consistent appearance along a direction of uniformity; separating the green image data into an original green test image comprising pixels; generating a test one-dimensional image based on a mathematical operation performed on the original green test image along the direction of the uniformity; determining a resolution of the optical system along the direction of the uniformity based on the test one-dimensional image and the known spacing of the contrast structures of the optical test target; as well as Outputs the determined resolution.

13. A computer device according to claim 12 or any one of the preceding claims, wherein: The direction of the uniformity includes horizontal or vertical.

14. A computer device according to claim 12 or any one of the preceding claims, wherein: The mathematical operation includes at least one of convolution, summation or averaging.

15. The computer device of claim 14, wherein: The direction of the uniformity includes horizontal or vertical; and The mathematical operation comprises a convolution along the direction of the uniformity using an array having an orientation matching the direction of the uniformity, such that: When the direction of the uniformity is horizontal, the array is a horizontal array having a horizontal orientation; as well as When the direction of uniformity is vertical, the array is a vertical array with a vertical orientation.

16. A computer device according to claim 12 or any one of the preceding claims, wherein: Determine that the optical system has: a resolution that at least matches the known spacing when the contrast structure is discernible in the test one-dimensional image; When the contrast structure is not discernible in the test one-dimensional image, it is smaller than the resolution of the known spacing.

17. A color image processing apparatus according to claim 12 or any one of the preceding claims, wherein: The optical test target is a Ronchi line.

18. A measurement system for measuring an optical property of an optical system using an optical test target and a light source, the measurement system comprising: a color camera configured to capture and output images in a color space; a colorimeter configured to output values ​​in an XYZ color space; as well as Computer device according to claim 1 or any one of the preceding claims.

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