KR100673644B1 - Method of evaluating flare and apparatus thereof - Google Patents

Abstract

A method and an apparatus for evaluating flare are provided to numerically represent flare generated in an accomplished image module to quantitatively evaluate the flare. A flare evaluating method includes steps of taking a picture of a to-be-evaluated object while varying an angle between an image module to be evaluated and the optical axis of a light source at a predetermined interval(S1), commonly setting a data sampling point at a position having a predetermined distance from the center of the acquired image(S2), and acquiring data about light at the data sampling point of the plurality of acquired images(S3). The data about light is intensity. The data sampling point corresponds to an edge located distant from the center of the image.

Description

Flare evaluation method and evaluation device {METHOD OF EVALUATING FLARE AND APPARATUS THEREOF}

1 is a photograph showing a determination method for the presence or absence of a flare phenomenon according to the prior art.

2 is a perspective view showing a flare evaluation apparatus according to the present invention.

3 is a diagram schematically showing a relationship between an irradiation light source and a flare in an image.

Figure 4 is a flow chart for flare measurement and evaluation method according to the present invention.

5 is an exemplary graph showing a flare presence evaluation example according to the present invention.

6 is a diagram schematically showing a relationship between an irradiation light source and a flare in an image applied to the present invention.

7A to 7D are photographs showing image results captured by the present invention with respect to an image module sample.

8 is a superimposed graph for flare quantification according to the present invention.

9 is a photograph taken to determine the validity of the graph results shown in FIG.

<Description of Major Symbols in Drawing>

1: Subject under evaluation (image module)

2: light source 21: optical cable

3: base 31: pinhole 32: focus adjustment pattern

4: support

5: Image module holder

6: Image module holding part

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flare evaluation method and an evaluation device, and more particularly, to a flare evaluation method and an evaluation device that can quantitatively evaluate a flare phenomenon generated in a completed image module.

Recently, due to the rapid development of information and communication technology, the improvement of data communication speed and the increase of data communication amount are realized, and the imaging devices such as CCD image sensor and CMOS image sensor are mounted on mobile electronic devices such as mobile phones and laptops. It is spread | distributing and these can transmit the image data image | photographed by the image module besides the text data by real-time process.

In addition, in the digital camera or mobile phone using the image pickup device, the compactness of the device or the module size is in progress, and the unit, the component, etc. constituting the image pickup device can be miniaturized. This phenomenon is applied to a photographing optical system including a plurality of lenses. The same is true.

On the other hand, a flare phenomenon occurs due to the miniaturization of the imaging device and the miniaturization of the lens assembly and the diffuse reflection of light as the arrangement interval between the lens barrel and the housing becomes dense. The flare refers to a phenomenon in which light reflected by an internal lens such as a photographing optical system by strong direct sunlight such as sunlight causes uneven exposure to an image pickup device such as a CCD or a CMOS of a light receiving unit, thereby degrading the sharpness of an image.

In the image module of the finished product as a determination method for the presence or absence of flare, first, as shown in Figure 1, the fluorescent light is placed outside the edge of the screen and the fluorescent light is reflected inside the image module to appear inside the screen The degree of flare was judged. In FIG. 1, a circled portion represents a flare. However, this determination method has a problem in that it is impossible to set the criteria for quantitative evaluation of specific flares and determination of good / failure of flares of image module products because flare occurrence is simply dependent on the view of the evaluator.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a flare evaluation method and an apparatus for evaluating quantitatively by quantifying flare phenomenon generated in a completed image module. There is.

In order to achieve the above object, the flare evaluation method according to the present invention comprises the steps of photographing the image at each target interval in the target to be evaluated while changing the angle between the image module and the optical axis of the light source to be evaluated at regular intervals; Setting a data sampling point in common at a position spaced a predetermined distance from a center of the image photographed at a predetermined angular interval; And acquiring data on light at data sampling points of the plurality of images photographed at the predetermined angular intervals.

Here, the angle between the object to be evaluated and the optical axis of the light source is changed at a predetermined interval, and the incident angle of light incident on the object to be evaluated is changed at a predetermined interval.

The incidence angle may include an angle for allowing a plurality of incident lights generated when the angle between the object under evaluation and the optical axis of the light source to be changed at a predetermined interval to pass through the set data sampling point.

Here, it is preferable that the data for the acquired light is light intensity.

The set data sampling point may be an edge portion spaced horizontally or vertically from the center of the image.

The edge part may correspond to one of incident angles of a plurality of lights generated when the angle between the object to be evaluated and the optical axis of the light source is changed at a predetermined interval.

Here, the set data sampling point is an area designated on a program.

The changing of the angle between the object under evaluation and the optical axis of the light source at a predetermined interval is performed by rotating the object under evaluation at a constant angle interval, or the optical axis of the light source irradiated to the object under evaluation It characterized by consisting of rotating at a constant angular interval.

The method may further include graphing data of a plurality of incident lights acquired at the data sampling point and evaluating the presence or absence of flare by determining the symmetry of the graphed data based on the incident angle corresponding to the data sampling point. .

Also, based on the angle of incidence corresponding to the data sampling point in the graph, quantifying flare intensity by a difference between an incident light data value for an angle smaller than the reference incident angle and an incident light data value for an angle greater than the incident angle. It features.

The data value may be an integral value, and the quantification of the flare may include an integral value obtained by curve fitting the incident light data value for an angle smaller than the standard incident angle by 'Standard Fit', and 'Flare Fit'. Is calculated by "flare (%) = {(Flare Fit-Standard Fit) / Standard Fit} x 100" when? Represents an integral value obtained by curve fitting the incident light data value with respect to an angle larger than the reference incident angle.

On the other hand, in order to achieve the above object, the flare evaluation apparatus according to the present invention, the light source; A base having a pinhole formed so that light emitted from the light source passes in the direction of the image module via an optical cable, and a focus adjusting pattern formed on a surface thereof; A support having one end supported by the base; An image module holder whose one end is coupled to the support to enable distance adjustment in the longitudinal direction of the support; An image module holding part installed at the other end of the image module holder so as to be rotatable at a predetermined angle with respect to the image module holder; And a data processor configured to sample and process the optical data at a position spaced a predetermined distance from the center of the image captured by the image module.

Hereinafter, after describing the flare evaluation apparatus and the evaluation method according to the present invention, specific embodiments will be described.

Flare rating device

2 is a perspective view showing a flare evaluation apparatus according to the present invention.

As shown in FIG. 2, the flare evaluation apparatus according to the present invention is largely supported by a light source 2, a base plate 3 to which the light source is irradiated, and one end of the lower side thereof to the base 3. An image module holding part installed to be rotatable at a predetermined angle on the support 4 to be coupled, the image module holder 5 to be movable in the longitudinal direction of the support 4, and the image module holder 5. 6).

The light source 2 irradiates a constant light onto the image module 1 to be evaluated, and it is preferable to use a halogen lamp. Here, if the amount of light is changed by adjusting the power of the halogen lamp, it is difficult to guarantee the same measurement result at every measurement, and there is a possibility that the effect of the color temperature change may occur. Therefore, after applying the full power of the halogen lamp, It is preferable to change the diameter of the pinhole 31 to be described later.

The base portion 3 is a plate for stably and structurally supporting the structure holding the image module 1 to be evaluated, that is, the support and the image module holder 5 and the image module holding portion 6. ), A pinhole 31 is formed so that light emitted from the light source 2 passes in the direction of the image module 1 via the optical cable 21.

The pinhole 31 may be generally applied in the range of 1 mm to 3 mm in diameter, for example, when using a halogen lamp of 15 V 150 W as a light source, when the light source is 1/3 power for a diameter of 3 mm. The change in the amount of light is so large that it is inadequate as a flare evaluation and quantification criterion, and when the light source is 1/2 power or full power, the amount of light is excessive and insufficient for evaluating flare. In addition, when the light source is 1/3 power for the diameter of 1 mm, the light quantity is large and the light quantity is small for evaluating flare, but when the light source is 1/2 power or full power, the light quantity is small and the light quantity is small. It is also suitable for observing flare phenomenon.

In addition, a focus adjustment pattern 32 is patterned on the surface of the base 3 to determine whether the image focus of the image module 1 is accurately implemented.

The support 4 is installed in the vertical direction so that one end of the lower side thereof is supported and coupled to the base 3, and typically its height corresponds to a range of 900 mm or less, and the base 3 and the image module 1 are supported. It controls the distance from).

One end of the image module holder 5 is coupled to the support 4 so that height adjustment is possible along the longitudinal direction of the support 4. Also, at the other end thereof, a goniometer may be attached to recognize the rotation angle of the image module holding part 6 which will be described later.

The image module holding part 6 is installed at the other end of the image module holder 5 so as to be rotatable at a predetermined angle about the image module holder 5. Preferably, the position of the image module 1 held by the image module holding part 6 is set to match the position of the optical axis irradiated from the light source 2.

On the other hand, the present invention includes a data processing unit (not shown) for acquiring flare information from an image captured by the image module by the structure described above. The data processing unit may serve to sample and process optical data such as light intensity at a position spaced a predetermined distance from the center of the image captured by the image module, and a general microcomputer may correspond thereto.

Flare Measurement and Evaluation Method

The flare evaluation method according to the present invention is basically based on the fact that it occurs from the position of the irradiation light source toward the center of the image as shown in FIG. That is, FIG. 3 is a diagram schematically showing the relationship between the irradiation light source and the flare in the image, wherein the incident angles from the irradiation light source to the image module are 0 °, 10 °, 20 °, 30 °, 35 °, and 40 °. The flare generation pattern for each incident angle in one case is shown, indicating that all of the flares are generated toward the center of the image.

Figure 4 shows a flow chart for the flare measurement and evaluation method according to the present invention.

As a flare measuring method, first, an image is photographed at each predetermined interval in the target object while changing the angle between the image module to be evaluated and the optical axis of the light source at a predetermined interval, thereby obtaining a plurality of images for each angle. (step 1). This may change the angle of the light incident on the image module 1 by rotating the image module holding part 6 rotatably coupled to the image module holder 5 at regular angle intervals, but alternatively the evaluated object It may be made by rotating the light source 2 irradiated to the image module 1 as a target at regular angular intervals.

That is, by changing the angle between the target to be evaluated and the optical axis of the light source at regular intervals, the angle of incidence of the light incident on the target to be evaluated is changed at regular intervals. The incident angle may include an angle at which a plurality of incident lights generated when the angle between the object under evaluation and the optical axis of the light source is changed at a predetermined interval passes through the set data sampling point.

Next, the data sampling point is commonly set at a position spaced a predetermined distance from the center of the image photographed at the predetermined angular interval (step 2). The data sampling point is the same position common to all of the plurality of images photographed for each angle, and corresponds to a sampling position for acquiring data to be described later.

Here, a parameter that can represent optical characteristics due to the flare may be considered as the data, but it is preferable that optical intensity be considered as the parameter, and the light intensity will be described below. The set data sampling point is an edge portion spaced horizontally or vertically from the center of the image, wherein the edge portion is generated when the angle between the target object and the optical axis of the light source is changed at a predetermined interval. It is preferably set to correspond to one of the incident angles of the plurality of lights. On the other hand, such a data sampling point can be set on a program of the data processing unit, and is typically formed in an area of a pixel unit.

Then, after acquiring data about light at data sampling points of the plurality of images photographed at the predetermined angular intervals, the presence and the degree of flare are evaluated (step 3).

That is, as the flare evaluation method, as described above, the light intensity at the set data sampling point is calculated for each rotation angle (corresponding to the incident angle of light incident from the light source to the image module). It can be defined as

Intensity = 0.3 x Red + 0.59 x Green + 0.11 x Blue

After calculating the light intensity of each pixel (e.g. 50 x 50 pixels) corresponding to the set data sampling point, the average value is adopted.

Next, the presence or absence of flare may be determined by graphing the light intensity at the set data sampling point with respect to the incident angle of light incident from the light source to the image module. That is, the data of the plurality of incident light acquired at the data sampling point is graphed, and the symmetry of the graphed data is judged based on the incident angle corresponding to the data sampling point to evaluate the presence or absence of flare (step 4 -One).

5 is an exemplary graph illustrating a flare evaluation example of FIG. 3, wherein the X axis of the graph represents an angle of incidence into the image module, and the Y axis represents an acquired light intensity at the set data sampling point. For C, D. Here, the circled portion means an increase in light intensity generated by the influence of the flare.

Among the graphs for the four samples, showing symmetry around the incident angle of 20 ° corresponding to the data sampling point corresponds to a good image module in which no flare occurs. That is, in the case of Samples A, C, and D, the light intensity due to flare is increased between the incident angles of 30 ° to 40 °, and in the case of Sample B, the symmetry between the incident angles corresponding to the data sampling points is 20 °. It can be confirmed that it corresponds to a good image module in which no flare occurs.

Next, with respect to the incident angle vs. the light intensity graph at the set data sampling point, the light intensity on the left and right is compared based on the edge light corresponding to the set data sampling point. That is, based on the incident angle corresponding to the data sampling point in the graph, the flare intensity is quantified by the difference between the incident light data value for the angle smaller than the reference incident angle and the incident light data value for the angle greater than the incident angle ( step 4-2).

An example of a quantitative flare intensity calculation method for sample A of FIG. 5 will be described. Based on the incident angle of 20 ° corresponding to the data sampling point, the value obtained by integrating the light intensity measurement value corresponding to the left area of the graph (incident angle of 0 ° to 20 °) is referred to as 'standard light quantity' (hereinafter referred to as 'standard'). The value obtained by integrating the light intensity measurement value corresponding to the right region (incidence angle 20 ° to 40 °) of the graph based on the incident angle 20 ° corresponding to the data sampling point is' the amount of light including the effect of flare (hereinafter, 'Flare'). Therefore, the difference between the area of the right region corresponding to the amount of light including the influence of flare and the area of the left region corresponding to the reference light amount corresponds to the amount of light generated by the flare. Here, in order to determine a more accurate flare intensity, each light intensity measurement is curve-fitted to reference the integral values for the curve-fitted graphs (called 'Standard Fit' and 'Flare Fit', respectively). In addition, the amount of light generated by the flare may be calculated, and a specific calculation equation is shown in Equation 2 below.

% Flare = {(Flare Fit-Standard Fit) / Standard Fit} × 100

In Equation 2 in consideration of the possibility of the appearance of the flare according to the amount of light is divided into 'Standard Fit'.

Next, in step 5, the quality / defect of the image module to be evaluated is determined according to the result value of the flare (%) according to Equation (2). For 20% of results, an evaluation criterion may be set, "Can be applied in mass production, but needs improvement", and "Not applicable" for results exceeding 20%.

Example

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 6 to 10.

FIG. 6 is a diagram schematically showing a relation between an irradiation light source and a flare in an image applied in this embodiment, wherein an angle of incidence from the irradiation light source to the image module is within an angle of 2.5 ° within a range of 0 ° to 45 ° The image is taken while the image module holding unit 6 is rotated. As described above, FIG. 6 shows a flare generation pattern for each incident angle, indicating that all of the flares are generated toward the center of the image.

As a criterion of the evaluation environment, the evaluation environment was dark (0 Lux) and the brightness of the halogen lamp module used as the light source was 10 Lux. Here, a 15V 150W halogen lamp was used, and the diameter of the pinhole was set to 1 mm so that the change in the amount of light was small and the amount of light was also suitable so that the flare phenomenon could be observed.

7A to 7B show image results captured under the above-described shooting conditions for each of the image module samples SPL1, SPL2, SPL3 and SPL4.

Also, FIG. 8 is a data sampling point. First, a point of incidence angle 22.5 °, which is an edge part spaced from the center of the image, is set, and a graph of the result of calculating the light intensity at the set point by Equation 1 is shown. This graph is superimposed on the incident angle of 22.5 °. This superimposition graph is to find the degree of quantitative flare intensity by comparing the light intensity of the left and right with respect to the edge light corresponding to the set data sampling point. On the other hand, the data sampling point was set to a 50 × 50 pixel range on the MATLAB program of the data processor.

For the image module samples SPL1, SPL2, SPL3 and SPL4, the result of quantitatively calculating the result of the image and graph shown in FIGS. 7 and 8 by Equation 2 is as shown in the following table.

SPL 1 SPL 2 SPL 3 SPL 4 flare(%) 17.9 3.6 42.5 37.4

Numerical results for the image module samples SPL1, SPL2, SPL3, and SPL4 are in good agreement with the degree of flare in the image shown in FIG. 7, and the image module samples SPL1, SPL2, SPL3, and SPL4 are used. It can be seen that the same result as in Fig. 9 showing the actually taken image. In FIG. 9, the circled portion represents the flare.

According to the result of the flare (%) according to the above Table 1, it is determined whether good or bad of the image module to be evaluated. For the results of less than 10%, the result is "good" and for the results of 10% to 20%, Applicable but need to be improved ", and if the evaluation criteria of" not applicable "is set for a result of more than 20%, the image module sample SPL2 is" excellent ", SPL1 is" applicable but need improvement ", SPL3 and SPL4 It will be judged as `` not applicable '', and it will be able to determine whether the product is defective by a clear standard.

The present invention is not limited to the above-described embodiments, but can be variously modified and changed by those skilled in the art, which should be regarded as included in the spirit and scope of the present invention as defined in the appended claims. something to do.

According to the flare evaluation method and the evaluation apparatus of the present invention as described above, by providing a standard to quantitatively evaluate the flare phenomenon generated in the completed image module to provide a standard for flare evaluation It can be effective.

Claims (14)

Photographing the image at each target interval at the target object while changing an angle between the image module to be evaluated and the optical axis of the light source at a predetermined interval; Setting a data sampling point in common at a position spaced a predetermined distance from a center of the image photographed at a predetermined angular interval; And Acquiring data on light at data sampling points of the plurality of images photographed at the predetermined angular intervals; Flare evaluation method comprising a. The method of claim 1, Flare evaluation method, characterized in that for changing the angle between the optical target of the target to be evaluated and the light axis at a predetermined interval, changing the incident angle of the light incident to the target to be evaluated at a predetermined interval. The method of claim 2, The incident angle is flare evaluation method, characterized in that it comprises an angle to pass a plurality of incident light generated when changing the angle between the target to be evaluated and the optical axis of the light source at a predetermined interval. The method of claim 1, And the data for the acquired light is light intensity. The method of claim 1, The set data sampling point is a flare evaluation method, characterized in that the edge portion spaced horizontally or vertically from the center of the image. The method of claim 5, And the edge portion corresponds to one of the incident angles of a plurality of lights generated when the angle between the target to be evaluated and the optical axis of the light source is changed at a predetermined interval. The method of claim 1, And the set data sampling point is an area designated on a program. The method according to any one of claims 1 to 3, And changing the angle between the object under evaluation and the optical axis of the light source at a constant interval by rotating the object under evaluation at a constant angle interval. The method according to any one of claims 1 to 3, And changing the angle between the object under evaluation and the optical axis of the light source at regular intervals by rotating the optical axis of the light source irradiated onto the object under evaluation at a constant angle interval. The method according to any one of claims 1 to 3, Flare evaluation, characterized in that the graph of the data of the plurality of incident light acquired at the data sampling point, and to evaluate the presence or absence of flare by determining the symmetry of the graphed data based on the incident angle corresponding to the data sampling point. Way. The method of claim 10, Flare intensity is quantified by a difference between an incident light data value for an angle smaller than the reference incident angle and an incident light data value for an angle greater than the incident angle based on an incident angle corresponding to the data sampling point in the graph. Flare evaluation method. The method of claim 11, And said data value is an integral value. The method of claim 12, The quantification of the flare is calculated by the following formula flare evaluation method. % Flare = {(Flare Fit-Standard Fit) / Standard Fit} × 100 Here, 'Standard Fit' represents an integral value obtained by curve fitting incident light data values for angles smaller than the reference incident angle, and 'Flare Fit' represents an integral value obtained by curve fitting incident light data values for angles greater than the reference incident angle. Indicates. Light source; A base having a pinhole formed so that light emitted from the light source passes in the direction of the image module via an optical cable, and a focus adjusting pattern formed on a surface thereof; A support having one end supported by the base; An image module holder whose one end is coupled to the support to enable distance adjustment in the longitudinal direction of the support; An image module holding part installed at the other end of the image module holder so as to be rotatable at a predetermined angle with respect to the image module holder; And A data processing unit for sampling and processing optical data at a position separated by a predetermined distance from the center of the image captured by the image module; Flare evaluation device comprising a.

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