CN103813095B - Test chart and its application method - Google Patents
Test chart and its application method Download PDFInfo
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- CN103813095B CN103813095B CN201310544580.6A CN201310544580A CN103813095B CN 103813095 B CN103813095 B CN 103813095B CN 201310544580 A CN201310544580 A CN 201310544580A CN 103813095 B CN103813095 B CN 103813095B
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- mensuration region
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N17/00—Diagnosis, testing or measuring for television systems or their details
- H04N17/02—Diagnosis, testing or measuring for television systems or their details for colour television signals
Abstract
The present invention provides a kind of test chart for the spatial resolution that camera device is judged in more parts that can be in the visual field of camera device.Test chart（1）At least include a figure（110、120、140、160、180）.Respectively scheme the multiple rings arranged with including concentric circles（111）, Duo Gehuan（111）With the spatial frequency in the direction increase from periphery towards center.Each figure is additionally included in multiple rings（111）Outside at least one for configuring indicate in pairs（112）With（114）Or（113）With（115）, paired mark be configured at by the centers of multiple rings transversely or longitudinally on.
Description
Technical field
The present invention relates to the test chart for camera devices such as cameras and their application method.
Background technology
In the past, it is known that in order to evaluate the spatial frequency of camera, circular annular form grating was used（CZP：Circular Zone
Plate）.Such as the known CZP figures are photographed by video camera and by waveform monitor analyzer comment
During the signal of video signal of the valency video camera, there is the characteristic of the lens based on video camera or based on video camera sheet
The characteristic of body and cannot be distinguished by analyzer observation waveform change it is such the problem of.In order to dispose the problem, in Japanese Unexamined Patent Publication
In 2011-101100 publications, the test chart made using the known CZP figures is disclosed.As the test chart of the disclosure,
There are the horizontal resolution for evaluating camera etc. and 2 figures for evaluating vertical resolution.The test chart of horizontal resolution evaluation（Ginseng
According to Fig. 2 of above-mentioned publication）By the known CZP figures of the vertical line cut-out halved from central part or so, and by the left side after cut-out
The left side of side and the right of opposite side engage to make, thus, spatial frequency characteristic highest in central part, with towards level
Direction periphery and step-down.On the other hand, the test chart on vertical resolution evaluation（With reference to Fig. 3 of above-mentioned publication）, make
Schemed with known CZP, CZP figures are cut off by the horizontal line halved above and below central part, and by the top of the upside cut off
Made with the following engagement of opposite side, thus, spatial frequency characteristic highest in central part, with towards vertical direction periphery
Portion and step-down.By these horizontal resolution evaluations with and vertical resolution evaluation test chart, spatial frequency is in central part
Middle highest, with towards horizontal direction periphery or vertical direction periphery step-down, so as to be easy to differentiate the observation of test chart
Which in lens and body based on video camera the change of waveform be.
The content of the invention
But, only can be at the center from test chart in test chart disclosed in Japanese Unexamined Patent Publication 2011-101100 publications
In along the line of horizontal direction and from center along the line of vertical direction this 2 lines, evaluation space resolution ratio.
Therefore, it is an object of the invention to provide judge in a kind of more parts that can be in the visual field of camera device
The test chart of the spatial resolution of camera device.
In addition, it is an object of the invention to provide a kind of spatial resolution that camera device is determined using above-mentioned test chart
Assay method.
Another object of the present invention is to provide a kind of storage for being used to implement the embodied on computer readable of said determination method
Medium and computer program.
At least include the test chart of a figure there is provided a kind of according to an embodiment of the invention, it is characterised in that：Institute
Stating figure includes：Multiple rings, are multiple rings for arranging of concentric circles ground, the plurality of ring has to be increased in the direction from periphery towards center
Big spatial frequency；And at least 1 in pairs mark, be that at least one configured outside the plurality of ring indicates in pairs, this into
Mark is configured in the center by the multiple ring transversely or longitudinally on.
In addition, according to another embodiment of the present invention, there is provided a kind of assay method, it is characterised in that including：a）Receive
The numeral of the test chart described in any one in the technical scheme 1~5 of camera device from measured object is taken the photograph
As the step of signal；b）By from a figure at least one figure described in test chart described in the digital camera signal detection
The paired mark, the step of determining the mensuration region under certain angle of one figure；c）In the mensuration region from
Low spatial frequency towards high spatial frequency determine multiple measure lines the step of；d）In each of each measure line
In, a series of numerical data of the measure line is taken along from the digital camera signal, according to a series of number
At least one of cycle of the waveform that digital data is determined and amplitude, obtain and each described determine spatial resolution in line
Step；And e）Using the multiple spatial resolutions obtained respectively in multiple measure lines, described measured pair is obtained
The step of spatial resolution in camera device, the described mensuration region of elephant.
In addition, according to another embodiment of the invention, various have more is provided on above-mentioned test chart and assay method
The feature of body.
Brief description of the drawings
Fig. 1 is the overall top view for the test chart 100 for showing an embodiment of the invention.
Fig. 2（A）The figure for being the upside half amplification of central figure in the test chart by Fig. 1 and showing, Fig. 2（B）It is by
The figure that a part for centre figure is further exaggerated, Fig. 2（C）It is that Fig. 2 is shown（B）The amplifier section waveform of brightness that is determined
Figure.
Fig. 3 is to be shown with the test chart of an embodiment of the invention to evaluate the spatial resolution of camera device
The figure of measurement system.
Fig. 4 is shown by the measure flow of Fig. 3 spatial resolution execution of measure device, for evaluating camera device
Flow chart.
Fig. 5 is the embodiment of spatial resolution determination step for showing to be shown specifically in Fig. 4 measure flow
Determine the flow chart of processing.
Fig. 6（A）It is the figure for showing the image in multiple measure lines in rest image, Fig. 6（B）It is to show that these are more
The figure of the waveform for the brightness that the image that different 2 in individual measure line determine line is determined.
Fig. 7 is the figure for the oscillogram for being further shown specifically Fig. 6.
Fig. 8（A）It is the figure for the value for showing the numerical data that certain obtained in Fig. 5 measure processing is determined in line, Fig. 8
（B）It is the figure of the value of the numerical data for the part being further shown specifically in the measure line.
Fig. 9（A）、（B）It is to show that shown by the result step display of Fig. 4 measure flow, specified angle interval is 5
The figure of the display example of the measurement result of the situation of degree.
Figure 10（A）、（B）It is to show that specified angle interval is that the another measurement result of 5 degree of situation shows the figure of example.
Figure 11（A）、（B）Be show be with specified angle interval 1 degree of situation Fig. 9（A）、（B）Same measurement result
Show the figure of example.
Figure 12（A）、（B）Be show be with specified angle interval 1 degree of situation Figure 10（A）、（B）Same measure knot
Fruit shows the figure of example.
Figure 13 is the flow chart of the measure processing of the other embodiment for the resolving power determination step for showing Fig. 4.
Figure 14 is the oscillogram in the cycle for illustrating to utilize in Figure 13 measure processing.
Figure 15 is the flow chart of the measure processing of the another embodiment for the resolving power determination step for showing Fig. 4.
Embodiment
Hereinafter, referring to the drawings, the various embodiments of the present invention are described in detail.
Fig. 1 is the overall top view for the test chart 100 for showing an embodiment of the invention.As illustrated, test
Figure 100 has rectangular shape, with 16：9 aspect ratios（HDTV is used）.In addition it is possible to the camera device with measured object
Aspect ratio be set to other aspect ratios with meeting.As illustrated, test chart 100 has in the center configuration of rectangle frame 102
Centre Figure 110 and 4 peripheries Figure 120~180 being respectively configured in the corner of rectangle frame 102.Compared to the vertical chi of rectangle frame 2
Very little, central Figure 110 is the size of 1/3 degree, and each periphery Figure 120~180 are the sizes of 1/5 degree.
When Fig. 2 referring also to the upside half for being exaggerated central Figure 110 is to illustrate, such as Fig. 2（A）It is shown, center figure
110 4 position detection marks 112 configured with multiple rings 111 in the central concentric circles configured, around the ring,
113rd, 114,115 and the central central circular 116 in ring 111.Multiple rings 111 of concentric circles are by black
With it is white between brightness continuously change, so as to determine the decorative pattern for the concentric circles that spatial frequency is uprised from periphery towards center.It is empty
Between frequency from 350TV bars（Outside）Change turns to 1150TV bars（Central side）, rate of change is 10TV bars/cycle.TV bars refer to：Represent
In the horizontal width equal with the height of the vertical direction of picture, white black ordinate, which can be separated, is identified as the unit of several.
Now, white and black ordinate is calculated as 1 respectively.In 1 scan line, white black ordinate is rectangle equivalent to luminance signal
Ripple（Or sine wave）1 cycle.The crest of luminance signal be shown as white, trough be shown as it is black, so 1 cycle exist
In TV bars during equivalent to 2 amounts.In Fig. 2（B）In, further it is shown specifically the ring of 2 periodic quantities.In addition, in Fig. 2（B）
In, it is illustrated that change in a stage-like manner for gray level, but in fact, used the gray level continuously changed.In Fig. 2（C）In, by 2
The luminance standard of the ring generation of individual periodic quantity turns to 0~1 value and shown, brightness passes through function sin2X continuously changes.
The position detection mark 112,113,114,115 included in central Figure 110 is the position for automatically process decision chart
With its towards and the mark that uses.In addition, mark 112 and 114 represents to pass through the horizontal direction at the center of figure（Represent 0 degree with
The angle of 180 degree）（Represent the angle of 0 degree and 180 degree）, in addition mark 113 and 115 represent Vertical Square by the center of figure
To（Represent 90 degree and 270 degree）.In addition, such as Fig. 2（A）It is shown, by including black central circular in central Figure 110
116, so that it is determined that width is 2d central band-like portions 118.2d width is less than the diameter of border circular areas 116, so as to
Making the end of central side turns into the line of relatively straight line, thus avoids the configuration of the ring in central part and reduces the hair of error measurement
It is raw.From the region of the band-like portions 118, multiple lines of the measure line for determining spatial resolution are chosen for use as.As
The reasons why line is using multiple lines is determined to be：Deviation is produced in the measurement result of the spatial resolution of each line, because
This is used to reduce its influence.
The structure of periphery Figure 120~180 is mutually identical, and with the structure same with central Figure 110.Each all edge graphs with
Figure different point in center is：Zhou Biantu overall size is small and in the small point of multiple rings of center configuration.Each all edge graphs
Multiple rings（Such as periphery Figure 120 multiple rings 122）With with central figure identical 350TV bars（Outside）~1150TV bars
（Central side）Spatial frequency, but rate of change is 50TV bars/cycle, and compared to center figure, the rate of change in every 1 cycle is higher.
It is that center is black white black configuration, but can also invert the configuration in test chart 1 described above.
In addition, more than, illustrate for test chart white black figure i.e. as the black of the 1st color and as the 2nd color it is white this 2
Gray scale is the decorative pattern of gray level change between individual color.It is red in white black figure（R）, it is green（G）, it is blue（B）Each composition（Also claim
For " passage "）Value turns into identical value, so the data of some passage in RGB to be used to the brightness number for spatial frequency of making decision
According to.In addition, in test chart, additionally it is possible to using it is white it is black beyond other colors.For example, can as the 1st and the 2nd color
Use arbitrary 2 colors beyond black and white.The RGB of following represent when showing each color, representational 8 colors leads to
Each value in road（8 bits are showed）.
【Table 1】
| R | G | B | |
| White | 255 | 255 | 255 |
| Yellow | 255 | 255 | 0 |
| Cyan | 0 | 255 | 255 |
| Green | 0 | 255 | 0 |
| Magenta, | 255 | 0 | 255 |
| Red | 255 | 0 | 0 |
| Blue | 0 | 0 | 255 |
| Black | 0 | 0 | 0 |
In addition, table 1 only represents above-mentioned representational 8 colors, additionally it is possible to as arbitrary 2 colors beyond black and white,
Use other colors.
In arbitrary 2 colors beyond using black and white, make between the peak value of positive and negative between these 2 colors
The grey scale change of color.Thereby, it is possible to the change for the distribution for parsing the resolution ratio based on color.In addition, the change on gray scale,
The value of 3 passages of RGB channel can be made while changing or making 2 passages in 3 passages while changing or only making
One passage change.As the changing method of gray scale, such as level can be used.And then, additionally it is possible to not only make the 3 of RGB channel
Individual passage makes phase with same phase change（Such as 90 degree）Mutually stagger and change.By carrying the change of gray scale
Phase difference, it is possible to increase the measurement accuracy of spatial resolution.
Test chart 100 from the description above, passes through the multiple Figure 110 of configuration, 120~180, Neng Gouxiang in rectangle frame 2
Mutually independently evaluate the spatial resolution in the different regions in visual field.In addition, including the ring of concentric circles by each figure, at this
In a little each regions, the spatial resolution in multiple different directions can be evaluated.Thereby, it is possible in 0 degree to 360 degree of all directions
The spatial resolution in the region of the desired arbitrary quantity in upper evaluation visual field.
Next, reference picture 3, detailed description evaluates the survey of the spatial resolution of camera device using above-mentioned test chart 1
Determine system 300.As illustrated, measurement system 300 includes object photographed to the test chart 100 shown in Fig. 1, measured
Camera device 310 and receive the shooting output signal from the camera device 310 measure device 320.It is used as measured pair
The example of the camera device 310 of elephant, including set with digital camera, video camera, other arbitrary Camera systems
It is standby, such as smart mobile phone, portable phone, the module of these Camera systems.Device 320 is determined by determining special machine structure
Into or can by have as computer the machine of versatility realize.In the following description, to pass through personal computer
The example that PC implements measure device is illustrated.The PC possesses processor, input unit, stores the storage of computer program
Known key element as the output devices such as device, display.In addition, computer program can also be stored in embodied on computer readable
Storage medium in.
Reference picture 4, illustrates by being performed in the measure device 320 of the spatial resolution for evaluating camera device 310
Computer program implement measure flow.First, in initial step 400, from camera device 310, receive to test chart
100 photographed obtained from result output signal, be arranged in the buffer in PC.The output signal is such as camera
The static picture document of image, can realize the arbitrary form such as JPEG, BITMAP, PNG, TIFF.In addition, static as receiving
The method of image file, in addition to situation about directly being received from camera device 310, additionally it is possible to from network（Such as Ethernet）、
The storage medium such as capture card and USB receives the static picture document having been achieved with.Next, in step 402, determining institute
The measurement range of spatial frequency in the rest image of reception.That is, the center figure in such as 5 Figure 110,120~180 of selection
110, and then the direction of the spatial resolution by the specified central Figure 110 for determining the selection of angle.For example, by from the center of figure
Represent that 0 degree of angle of right horizontal direction is appointed as determining and start angle, and then, institute is specified in the range of 0.01 degree~90 degree
The angle interval of measure.In addition, in the present embodiment, determined on 4 directions, so 0 degree is being appointed as to determine simultaneously
In the case of starting angle, further specify 90 degree, 180 degree, the measure under 270 degree.
Next, in step 404, detecting the mensuration region of spatial resolution.Specifically, up and down 4 are being surrounded
It is scanned from left to right for each line in the quadrangle of individual position detection mark 112~115, is determined as four white sides
The coordinate of the mark 112 of shape~115.Next, being the angle of the left and right of the upside of mark 113 by white quadrangle above
Coordinate and following white quadrangle are the coordinate at the angle of the left and right of the downside of mark 115, it is determined that the mensuration region of longitudinal direction.Together
Sample, the white quadrangle by the left side is that the coordinate at the angle above and below the left side of mark 114 and the quadrangle on the right side indicate
The coordinate at the angle above and below 112 right side, it is determined that horizontal mensuration region.Next, obtaining the peak value of initial ring.In addition,
In order to more correctly determine spatial resolution, mensuration region is determined in the way of including multiple measure lines.In addition, also determining to make
With which measure line in mensuration region.
Next, in a step 406, the measure of spatial resolution is carried out in identified measure line, storage is determined
As a result.On the detailed of the measure, reference picture 5 is aftermentioned.Next, in a step 408, judging determining whether in mensuration region
Complete, when unfinished, ensuing mensuration region is selected in step 410.In addition, on step 410 processing it is detailed,
It is aftermentioned.Next, the spatial resolution for starting again at step 406 is determined.When being determined as that measure is completed in a step 408,
In step 412, the stored measurement result of display terminates the flow.
Next, reference picture 5, illustrate an embodiment of spatial resolution determination step 406 measure processing it is detailed
Carefully.In Fig. 5 measure processing, the exception in the generation of the peak value of the positive and negative in waveform is utilized.First, in step 500,
Initialized to determining buffer, to measure parameter（Line counter, inspection data pointer, result record buffer
Deng）Initialized.Next, in step 502, the measure line in each of the mensuration region in 4 directions of selection.On
The selection of measure line in mensuration region, substantially, carries out according to the order from left side to the right, from the upper side to the lower side, leads to
Cross line counter records.In each mensuration region, select 40 lines and be averaged value as measured value.Next,
In step 504, the high-frequency noise in the data of selected measure line is removed using such as Gaussian filter.It is specific and
Speech, is HD determining image（1920x1080）In the case of, 1 cycle of highest resolution is 2dot（Its frequency is
74.25MHz half）, so below 1 cycle 2dot frequency component is considered as into noise and removed.
Fig. 6 shows the image so obtained（Fig. 6（A））With the waveform of the data of the image（Fig. 6（B））.In the figure, show
Go out the image of multiple lines including horizontal line 535 and horizontal line 540, in the oscillogram of downside, by horizontal line
535 and horizontal line 540 brightness change be standardized as 0~1 scope.Fig. 7 is the figure for the oscillogram for being exaggerated Fig. 6, can
Know in horizontal line 535 and horizontal line 540, sampled point is slightly offset.Therefore, as described above, in the reality of the present invention
Apply in mode, in each mensuration region, spatial resolution is determined by multiple measure lines.
Next, in step 506, by carrying out the pretreatment of view data, so that as only with crest and trough
Peak value data.Specifically,（1）The peak value of crest and trough is determined in all cycles of the waveform of view data,（2）
In each cycle, it is in the data between two peak values in crest and trough, rise on the way in data, i.e. be in it is upper
Rise along peak value to the data between the peak value of ensuing crest of trough when starting all be transformed to the rising edge and start when
Trough peak value data value,（3）In each cycle, in the data between two peak values in crest and trough,
Data in declining on the way, the peak value of crest when starting in trailing edge are to the data between the peak value of ensuing trough
The data value of the peak value for the crest being all transformed to when the trailing edge starts.Next, in step 508, obtaining and being preconditioned
Data average value, the average value is determined as to the threshold value of the peak value for judging crest and trough, and the threshold value is made
For the value of " slider ".
Fig. 8 shows the data obtained by step 506 and 508 processing.Specifically, Fig. 8（A）It is shown as one
Example includes the digital value of the brightness data 1~560 in the line that 0 degree and 180 degree this 2 determine line, Fig. 8（B）It is
Will be in Fig. 8（A）The figure that the middle brightness data 157~177 surrounded with four sides amplifies and shown.In addition, in figure, in order to understand this
Invention, shows the slider with the value obtained in above-mentioned.Such as it was found from figure, peak value periphery not including crest and trough with
Outer data.
Next, in step 510, indicate the inspection data pointer of the data of the check object in measure line
Initialization, indicates the initial data that should start to check.Specifically, when the angle of measure line is 0 degree, right-hand member is indicated
Data, at 90 degree, indicate the data of upper end, in 180 degree, indicate the data of left end, at 270 degree, indicate the number of lower end
According to.For example, in Fig. 8（A）Example in, check data pointer when have selected 0 degree of measure line, designation number data 560,
When have selected the measure line of 180 degree, designation number data 1.
Next, in step 512, judge to check data pointer whether the center of arrival figure, the measure i.e. with have selected
The inspection starting position opposite side of line.By detecting more than the whether continuous a certain fixed number of black data, the judgement is carried out.
When being judged to reaching, it is judged as having checked and having entered step 520 in selected measure line.It is being judged to not reaching
When, into step 514.
In the step 514, judge pointer indicate data whether the trailing edge partial response with waveform.By determining whether
Less than the value in the data only then above checked, the judgement of trailing edge part is carried out.It is being determined as not trailing edge part, i.e.
It is equal to or during more than value in the data only then above checked（In Fig. 8（B）Example in data 800,801）, enter
Step 516, inspection data pointer is made to shift 1 and return to step 512 to center position.On the other hand, in the step 514, sentence
It is set to when being trailing edge part（In Fig. 8（B）Example in data 802,804）, in following step 517, judge to check
In the values of data whether compare slider（Represent threshold value）In above.When being judged to being in above than slider（In Fig. 8
（B）Example in data 804）, according to the trough for not occurring more than slider（White black thicken and can not differentiate）, it is determined as
Exceeded the upper limit of spatial resolution, by with the data only then above checked（In Fig. 8（B）Example in data 801）'s
The corresponding spatial resolution in position is judged as higher limit, records the value in the pointer of the data and then above checked.
In step 517 in the case of "Yes", the spatial resolution judged respectively is defined as to the measure line in checking
In measurement result.Specifically, the value of pointer is scaled to the position on figure, calculates corresponding with position on the figure converted
The bar number of TV bars.The TV bar representation space resolution ratio calculated.Next, in step 522, its measurement result is preserved
Into specified buffer.
In addition, in the present embodiment, used the trailing edge in step 514 detect and step 517 in whether than cunning
Dynamic device is in the combination of judgement above, but it is also possible to make other method.For example, can also detect and rise in the step 514
Edge, in step 517, determines whether than slider in following.
Next, in step 524, determining whether for 4 directions（0 degree, 90 degree, 180 degree, 270 degree）All surveys
Determine line and complete measure, when unfinished, select ensuing measure line and enter step 510, afterwards step 512 repeatedly
~522 the step of.On the other hand, when all measure lines on 4 directions complete measure, in step 526, sentence
It is fixed whether complete 4 mensuration regions each in all measure lines in measure, when unfinished, into step 502,
Select each the ensuing measure line in 4 mensuration regions.Although for example, when Fig. 6 measure determined in line 535
Complete, but when not being measured the measure of line 540, selection determines line 540.Afterwards, above-mentioned steps 504~524 repeatedly.
When the measure in all measure lines in each mensuration region is completed, in step 528, obtain many in each mensuration region
The average value of measurement result in individual mensuration region, the TV bar values as the average value are determined as in corresponding mensuration region
Final spatial resolution, is saved in results buffer.Thus, the final spatial resolution on 4 directions is obtained.
Afterwards, into Fig. 4 step 408, when the measure in all mensuration regions is not yet completed, select in step 410
Select ensuing mensuration region.That is, for example, when the measure in 0 degree, 90 degree, 180 degree, 270 degree of mensuration region is completed,
Mensuration region is selected in ensuing 4 angles that have left specified angle interval.For example, between the angle specified
In the case of being 5 degree, 5 degree, 95 degree, 185 degree, 275 degree of mensuration region are selected.When at specified angle interval being 1 degree,
Select 1 degree, 91 degree, 181 degree, 271 degree of mensuration region.Herein, in the selection of ensuing mensuration region, enter to exercise decision
The coordinate of area of space corresponding with mensuration region, the center to scheme spatially rotates the computing at specified angle interval as axle,
Then the coordinate of the area of space after the rotation as its result is obtained, and is used as the seat for determining ensuing mensuration region
Mark.In addition, the Space Rotating of coordinate can be carried out by known method, for example, it can be carried out by using following formula.
【Formula 1】
Herein, F（x、y）It is former coordinate, F '（X ', y '）It is coordinates of targets, σ is the anglec of rotation.F and F ' origin is overlapping,
So being F（0,0）=F‘（0,0）.
Next, in a step 408, after the completion of being determined in all mensuration regions, into step 412, being shown in knot
The measurement result of storage in fruit buffer.One example of measurement result is shown in following tables（Specified angle interval=5 degree）
（Middle value is omitted）.
【Table 2】
In addition, x coordinate is the x-axis of the position on the figure for the upper limit position for representing representation space resolution ratio（Transverse axis）Seat
Mark, y-coordinate is the y-axis of the position（The longitudinal axis）Coordinate.On its measurement result, the side except showing result with above-mentioned sheet form
Beyond method, additionally it is possible to show measurement result in a variety of forms as following explanation.
Fig. 9（A）It is to show that transverse axis represents the angle of mensuration region, the figure of the value of the TV bars of longitudinal axis representation space resolution ratio.
Fig. 9（B）Be transverse axis be above-mentioned x coordinate and the longitudinal axis be above-mentioned y-coordinate figure.Therefore, Fig. 9（B）Result show with as its source
Map space on correspondence.
Next, Figure 10（A）It is the display of polar form, by Fig. 9（B）Result show as the plotting of " x "
Overlapping display in test chart, representation space resolution ratio is in which position on figure.Therefore, it is possible to associate grasp with figure
The spatial resolution of 360 degree of scopes.In addition, Figure 10（B）Be also the display under polar form, by under certain angle away from pole
Distance represents the value of the TV bars under the angle.Therefore, the size of the length representation space resolution ratio of the line away from pole, center is represented
The circumferential part of 0TV bars, white circle（Edge）For 1150TV bars.Under the display format, 360 degree of scopes are also will appreciate that
The distribution of spatial resolution.
Figure 11（A）, Figure 11（B）, Figure 12（A）, Figure 12（B）It is and Fig. 9（A）, Fig. 9（B）, Figure 10（A）, Figure 10（B）Respectively
Same figure, result when showing to make specified angle interval turn into finer 1 degree.
Next, reference picture 13, illustrate at the measure of another embodiment of resolving power determination step 406 as Fig. 4
Reason.In this embodiment, the length in the cycle in waveform is utilized in the judgement of spatial resolution.As illustrated, Figure 13
The step of determining and handle similar with Fig. 5 measure processing, different points are, including binarization step 1301, and replace Fig. 5
506 and step 512~520, include the point of step 1300 and step 1302~1310.
Specifically, in step 1300, in addition to the pretreatment of Fig. 5 step 506, by the peak value of crest to connecing down
The peak value of the trough come regard the peak value of the peak value of trough to ensuing crest as " crest data " as " trough data ".
Or, it is used as different methods, additionally it is possible to using the peak value of the peak value of crest to ensuing trough as " crest data ", by ripple
The peak value of the peak value of paddy to ensuing crest is used as " trough data ".Whether which, is all divided into crest by Wave data
Data and trough data this 2.Next, in step 1301, with respect to the data that this is preconditioned, being entered by the value of slider
Line slip, so that binaryzation is carried out, thus, the binaryzation waveform of generation as shown in Figure 14.In addition, the part of dotted line is waveform
1 cycle portions.
After such processing has been carried out, in step 1302, determine whether to have detected 1 cycle.It is used as an example
Son, when initially have detected " trough data ", not 1 cycle, so into step 1304, herein, making inspection data pointer
Advanced 1 and return to step 1302 to central side.Herein, determine whether to have detected 1 cycle again.For example, in this detection
When " crest data ", because last time have detected " trough data ", it is determined that to have detected 1 cycle.Now, into step
Rapid 1306, herein, detecting whether to be first for 1 cycle is judged, when first, in step 1308 by the week in 1 cycle
Phase length recorded in buffer, afterwards into step 1304.On the other hand, when being determined as not first in step 1306,
In step 1310, determine whether long longer than the cycle stored in 1 cycle, the i.e. buffer that detects before this.In not long feelings
Condition, be shorter or identical length in the case of, in step 1312, recorded in the cycle length that have detected this slow
After rushing device and have updated cycle length, into step 1304, ensuing inspection is transferred to.On the other hand, in step 1310
When being determined as long, on this detection cycle, be determined as that black and white thickens and cannot be distinguished by, according to only then before inspection
The value of data pointer is looked into, the value of the TV bars at the position of coordinate and the coordinate on figure is obtained.Afterwards, into Fig. 5 the step of
The same step of 522 later steps, so as to generate final measured value.
In addition, reference picture 15, illustrates that the measure of the another embodiment of the resolving power determination step 406 as Fig. 4 is handled.
In this embodiment, in the judgement of spatial resolution, the amplitude in waveform is utilized.As illustrated, Figure 15 measure processing
Measure processing with Fig. 5 is similar, and difference is, no Fig. 5 step 508, also, replaces Fig. 5 step 506 and step
512~520, include the point of step 1500 and step 1502~1506.
Specifically, in step 1500, in addition to the pretreatment of Fig. 5 step 506, the processing with Figure 13 is same
Ground, using the peak value of the peak value of crest to ensuing trough as " trough data ", by the peak value of trough to ensuing crest
Peak value be used as " crest data ".Or, it is used as different methods, additionally it is possible to by the peak value of crest to the peak of ensuing trough
Value is used as " crest data ", regard the peak value of the peak value of trough to ensuing crest as " trough data ".Whether which,
Wave data is all divided into crest data and trough data this 2.After such processing has been carried out, in step 1502,
Determine whether to have detected 1 cycle.As an example, when initially have detected " trough data ", not 1 cycle, so
Into step 1504, herein, inspection data pointer is set to advance one and return to step 1502 to central side.Herein, determine whether
1 cycle is have detected again.For example, when this have detected " crest data ", last time have detected " trough data ", it is determined that
To have detected 1 cycle.Now, into step 1506, herein, judge whether the amplitude in 1 detected cycle is less than and make a reservation for
Threshold value.In the case of not less than threshold value, it is judged as that Bai Heiwei thickens and is detected, subsequently into step 1504, turns
Move on to the inspection for ensuing data.On the other hand, in the case of less than threshold value, be judged as it is white it is black thicken, root
According to only then before inspection data pointer value, obtain the value of the TV bars at the position of coordinate and the coordinate on figure.Afterwards,
Into the same step of the later step of the step 522 with Fig. 5, so as to generate final measured value.
If using the test chart of the invention of detailed description above, difference that could be in each region in 360 degree
Direction on spatial resolution in field of view different on evaluation space, thus, it is possible to evaluate in more detail than ever.Separately
Outside, according to the assay method of the present invention, above-mentioned test chart can be used to carry out reliably evaluation space resolution ratio, and it is evaluated knot
Fruit shows in the form of user is easy to know.
Claims (16)
1. a kind of at least include the test chart of a figure, it is characterised in that：
The figure includes：
Multiple rings, are multiple rings for arranging of concentric circles ground, and the plurality of ring has in the direction increase from periphery towards center
Spatial frequency；And
At least one indicates in pairs, is that at least one configured outside the plurality of ring indicates in pairs, the paired mark is configured in
By the center of the multiple ring transversely or longitudinally on,
The mensuration region that each pair of determination that described at least one indicates in pairs is used in the measure of spatial resolution, passes through correspondence
To the width of mark determine the width of the mensuration region.
2. test chart according to claim 1, it is characterised in that：
The figure includes black border circular areas at the center of the multiple ring,
The border circular areas have and the direction orthogonal with being configured with the described horizontal or described longitudinal direction of the mark on described in
The diameter of the width association of mark.
3. test chart according to claim 1, it is characterised in that：Each of the multiple ring, is determining the space
Turn into the 1st color at the peak value of one side of the waveform of frequency, turn into the 2nd color at the peak value of the opposing party, in one
Color changes between the 1st color and the 2nd color between peak value and the peak value of described the opposing party.
4. test chart according to claim 1, it is characterised in that：
The test chart has rectangular shape, and including multiple figures,
The plurality of figure includes：
Centered Graphs, are configured at the center of the rectangle of the test chart；And
4 Zhou Biantu, are configured at each of the corner of the rectangle.
5. a kind of assay method, it is characterised in that including：
A) test described in any one in the Claims 1 to 4 of the camera device from measured object is received
The step of digital camera signal of figure；
B) by from a figure at least one figure described in test chart described in the digital camera signal detection it is described into
To mark, the step of determining the mensuration region under certain angle of one figure；
C) in the mensuration region from low spatial frequency towards high spatial frequency determine multiple measure lines the step of；
D) in each of each measure line, a company of the measure line is taken along from the digital camera signal
At least one of the numerical data of string, cycle of the waveform determined according to a series of numerical data and amplitude, are obtained
It is each it is described determine line in spatial resolution the step of；And
E) using the multiple spatial resolutions obtained respectively in multiple measure lines, taking the photograph for the measured object is obtained
As the step of device, spatial resolution in the mensuration region.
6. assay method according to claim 5, it is characterised in that：
The step of obtaining the spatial resolution in each measure line includes：
The step of the detection of the peak value of the waveform the low spatial frequency；
The step of peak value of the polarity of one side of the average value no more than the waveform in the peak value detected；With
And
According to the spatial frequency, the step of determining the spatial resolution in each measure line, the spatial frequency is with having
Have no more than the average value a side polarity peak value and then before the side more than the average value polarity
Peak value waveform position correspondence.
7. assay method according to claim 6, it is characterised in that：Pass through the institute obtained in the multiple measure line
The average value of multiple spatial resolutions is stated to determine the spatial resolution of the mensuration region.
8. assay method according to claim 5, it is characterised in that：
The step of obtaining the spatial resolution in each measure line includes：
The step of the detection in the cycle of the waveform the low spatial frequency；
Judge cycle for being detected whether than in the cycle and then above detected longer step；And
The cycle detected than it is longer in the cycle and then above detected when, according to with described before and then
The corresponding spatial frequency of waveform position in the cycle of face detection, determines each step for determining the spatial resolution in line
Suddenly.
9. assay method according to claim 5, it is characterised in that：
The step of obtaining the spatial resolution in each measure line includes：
The step of the detection of the amplitude of the waveform the low spatial frequency；
The step of whether amplitude detected is less than threshold value judged；And
The amplitude detected be less than the threshold value when, according to with the amplitude in the detection and then above detect
Amplitude the corresponding spatial frequency of waveform position, determine it is each it is described determine line in spatial resolution the step of.
10. assay method according to claim 5, it is characterised in that also include：
Make the mensuration region, certain angle is rotated centered on the center of one figure, mensuration region after generation rotation
Step；And
On mensuration region after the rotation, the step of performing described step c, d, e.
11. assay method according to claim 5, it is characterised in that also include：By what is obtained in the mensuration region
Represent that the value of the spatial resolution and the angle relation of the mensuration region get up the step of showing.
12. assay method according to claim 11, it is characterised in that：The spatial discrimination is represented by polar coordinates display
The angle of the value of rate and the mensuration region.
13. assay method according to claim 12, it is characterised in that：Distance away from pole and institute in the polar coordinates
State multiple rings center and with the distance represent spatial frequency the figure the multiple ring-type position between away from
From correlation.
14. assay method according to claim 13, it is characterised in that：Distance away from pole in the polar coordinates with it is described
Spatial resolution is related.
15. assay method according to claim 14, it is characterised in that：The distance at the polar coordinates Zhong Ju centers is represented
Represent the value of the spatial resolution.
16. assay method according to claim 11, it is characterised in that：The space point is represented by orthogonal coordinates display
The angle of the value of resolution and the mensuration region.
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| JP2012244379A JP6061133B2 (en) | 2012-11-06 | 2012-11-06 | Test chart and its usage |
| JP2012-244379 | 2012-11-06 |
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| CN107113421B (en) * | 2016-08-09 | 2018-07-06 | 深圳市瑞立视多媒体科技有限公司 | The detection method and device of a kind of optical system imaging quality |
| JP6860377B2 (en) * | 2017-02-24 | 2021-04-14 | 日本放送協会 | Chart for MTF measurement |
| JP7058102B2 (en) * | 2017-10-16 | 2022-04-21 | 日本放送協会 | Resolution characteristic measuring device and its program |
| CN109951699B (en) * | 2017-12-21 | 2021-06-11 | 深圳Tcl新技术有限公司 | Method and device for testing television display scale and storage medium |
| JP7340381B2 (en) * | 2019-08-07 | 2023-09-07 | 日本放送協会 | Spatial frequency ratio measuring device and its program |
| CN111131810A (en) * | 2019-12-19 | 2020-05-08 | 北京中科慧眼科技有限公司 | Lens definition measuring method, device and system and measuring chart |
| CN114719731B (en) * | 2022-06-08 | 2022-09-23 | 中国航发四川燃气涡轮研究院 | Blade tip clearance peak-to-peak value extraction method and blade rotating speed calculation method and device |
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| JPS62237889A (en) * | 1986-04-09 | 1987-10-17 | Sony Corp | Measuring method for image pickup tube beam spot shape |
| JP3282868B2 (en) * | 1993-02-05 | 2002-05-20 | 松下電器産業株式会社 | Resolution inspection method |
| KR19980076118A (en) * | 1997-04-07 | 1998-11-16 | 구자홍 | Focus-Resolution Inspection Mechanism and Method of Imager |
| KR100547362B1 (en) * | 2003-08-14 | 2006-01-26 | 삼성전기주식회사 | Image evaluation chart and efficiency test method using thereof |
| JP2006245891A (en) * | 2005-03-02 | 2006-09-14 | Mitsubishi Electric Corp | Chart for inspecting image of camera module, and image inspecting method and image inspecting device for the camera module using the chart for inspecting image |
| JP5083011B2 (en) * | 2007-04-19 | 2012-11-28 | パナソニック株式会社 | Method for evaluating camera shake correction function of image pickup apparatus and method for generating camera shake model waveform |
| JP4835610B2 (en) * | 2007-04-19 | 2011-12-14 | パナソニック株式会社 | Evaluation method of captured images |
| JP5420372B2 (en) * | 2009-11-04 | 2014-02-19 | 池上通信機株式会社 | Test chart and its usage |
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| JP6061133B2 (en) | 2017-01-18 |
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| CN103813095A (en) | 2014-05-21 |
| KR20140058373A (en) | 2014-05-14 |
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