The detection method of mobile phone cam color reducibility and system
Technical field
The present invention relates to the camera work field, particularly a kind of detection method of mobile phone cam color reducibility and system.
Background technology
The mobile phone cam module has become a standard configuration of mobile phone, and the client is also more and more higher to the requirement of mobile phone image quality, and the quality of digital picture is judged usually from several aspects measurement such as definition, white balance, color reducibility, GTG.Wherein, color reducibility is one of basic demand.、
In the prior art, the way of assessment camera color reducibility all is by image sensor standard 24 colour atlas to be taken under certain environment, then picture shot is imported among the PC, pictures taken is analyzed, thereby obtain the color reducibility performance of this image sensor.
Yet this method can also be carried out at laboratory stage, if but just wasted time and energy very much in the production phase: can reduce production efficiency, increase production cost.
In view of this, need provide a kind of can be in the more convenient technology of assessing the color reducibility of mobile phone cam accurately of production phase.
Summary of the invention
In view of above-mentioned the deficiencies in the prior art part, the object of the present invention is to provide a kind of detection method and system of mobile phone cam color reducibility, to solve mobile phone cam of the prior art in process of production, during assessment camera color reducibility, production efficiency is underground, production cost is crossed problems such as height.
In order to achieve the above object, the present invention has taked following technical scheme:
A kind of detection method of mobile phone cam color reducibility wherein, may further comprise the steps:
S1, mobile phone cam is taken standard 24 colour atlas, obtains first image;
S2 changes the chromaticity coordinate of each color lump of first image, obtains the first chromaticity coordinate collection;
S3 compares the first chromaticity coordinate collection and the standard colorimetric coordinate set that is stored in the mobile phone, obtains mean value and the root-mean-square value of color reducibility;
S4 with the mean value of color reducibility and root-mean-square value in default threshold value relatively, obtains testing result: if greater than threshold value, then be substandard product, otherwise, then be qualified products;
Wherein, described standard colorimetric coordinate set is Lab chromaticity coordinate collection.
The detection method of described mobile phone cam color reducibility, wherein, the described first chromaticity coordinate collection is Lab chromaticity coordinate collection.
The detection method of described mobile phone cam color reducibility wherein, also comprises step S5, and described testing result is presented on the mobile phone screen.
The detection method of described mobile phone cam color reducibility, wherein, the form of described first image is rgb format.
A kind of detection system of mobile phone cam color reducibility wherein, comprising:
Memory module is used for storage standards chromaticity coordinate collection and threshold value;
The chromaticity coordinate modular converter for the first chromaticity coordinate collection of the image that mobile phone cam is shot, converts the chromaticity coordinate form that is pre-stored in the mobile phone to;
The chromaticity coordinate comparison module is used for the standard colorimetric coordinate set of the first chromaticity coordinate collection and memory module is compared, and obtains mean value and the root-mean-square value of color reducibility;
Evaluation module is used for the threshold value of mean value, root-mean-square value and the memory module of color reducibility relatively: as if greater than then being substandard product, otherwise, then be qualified products;
Wherein, described standard colorimetric coordinate set is Lab chromaticity coordinate collection.
The detection system of described mobile phone cam color reducibility wherein, also comprises a display module, is used for the assessment result of evaluation module is shown.
The detection system of described mobile phone cam color reducibility, wherein, described display module is mobile phone display screen.
The detection system of described mobile phone cam color reducibility, wherein, the described first chromaticity coordinate collection is Lab chromaticity coordinate collection.
The detection method of mobile phone cam color reducibility provided by the invention and system, it is taken standard 24 colour atlas by mobile phone cam, obtain first image, change the chromaticity coordinate of each color lump of first image then, obtain the first chromaticity coordinate collection, again the first chromaticity coordinate collection and the standard colorimetric coordinate set that is stored in the mobile phone are compared, obtain the mean value of color reducibility and root-mean-square value and with the mean value of color reducibility and root-mean-square value in default threshold value relatively, obtain testing result: if greater than threshold value, it then is substandard product, otherwise, then be qualified products.Make that the production phase can the more convenient Performance Evaluation that accurately carries out camera, improved production efficiency, reduced production cost.
Description of drawings
Fig. 1 is the flow chart of the detection method of mobile phone cam color reducibility in the embodiment of the invention.
Embodiment
The invention provides a kind of detection method and system of mobile phone cam color reducibility.For making purpose of the present invention, technical scheme and effect clearer, clear and definite, below with reference to accompanying drawing and give an actual example that the present invention is described in more detail.Should be appreciated that specific embodiment described herein only in order to explaining the present invention, and be not used in restriction the present invention.
We assess the color reducibility of mobile phone cam usually with the difference of the color of the color of mobile phone cam actual photographed 24 colour atlas and standard 24 colour atlas.We are called color error to this index, and he has two indexs, and one is called absolute error (having comprised luminance difference), and another is exactly that color error has been ignored luminance difference.
In embodiments of the present invention, we represent that with following structure a color block (we can call it is first color block) is at the position of Lab chromaticity coordinate { L1, a1, b1}, and the reference colour of this color block is { L1` in the position of Lab chromaticity coordinate, a1`, so b1`} is Δ L=L1 – L1`, Δ a=a1 – a1`, Δ b=b1 – b1`.
So we can obtain the absolute error of this color lump
, color error
In like manner, other color lumps are also had corresponding absolute error Δ E2, Δ E3, Δ E4 ..., Δ E24; Color error Δ C2, Δ C3, Δ C4 ... thereby we can obtain the mean value of the color reducibility of this mobile phone cam Δ C24.
, root-mean-square value
,
Thereby we can assess this mobile phone cam color reducibility according to the mean value of setting the mobile phone cam color reducibility and the threshold value of root-mean-square value: if the mean value of this mobile phone cam color reducibility and root-mean-square value greater than threshold value, then are substandard product; Otherwise, then be qualified products.
See also Fig. 1, Fig. 1 is the flow chart of the detection method of mobile phone cam color reducibility in the embodiment of the invention.As shown in the figure, the detection method of mobile phone cam color reducibility of the present invention may further comprise the steps:
S1, mobile phone cam is taken standard 24 colour atlas, obtains first image;
S2 changes the chromaticity coordinate of each color lump of first image, obtains the first chromaticity coordinate collection;
S3 compares the first chromaticity coordinate collection and the standard colorimetric coordinate set that is stored in the mobile phone, obtains mean value and the root-mean-square value of color reducibility;
S4 with the mean value of color reducibility and root-mean-square value in default threshold value relatively, obtains testing result: if greater than threshold value, then be substandard product, otherwise, then be qualified products.
Further, described detection method also comprises step S5, and described testing result is presented on the mobile phone screen.
In embodiments of the present invention, described machine camera is taken first image that obtains to standard 24 colour atlas, its form is rgb format, and the standard colorimetric coordinate that is stored in the mobile phone is represented with the Lab chromaticity coordinate, so we need convert the chromaticity coordinate of RGB to the chromaticity coordinate of Lab usually.Its conversion formula is as follows:
And the color reducibility by color lump to be measured (i.e. the color lump of first image) and standard color block assessment camera, this realizes that principle is common practise, does not just do description here one by one more.
Simultaneously, the present invention also provides a kind of detection system of mobile phone cam color reducibility, comprising:
Memory module is used for storage standards chromaticity coordinate collection and threshold value;
The chromaticity coordinate modular converter for the first chromaticity coordinate collection of the image that mobile phone cam is shot, converts the chromaticity coordinate form that is pre-stored in the mobile phone to;
The chromaticity coordinate comparison module is used for the standard colorimetric coordinate set of the first chromaticity coordinate collection and memory module is compared, and obtains mean value and the root-mean-square value of color reducibility;
Evaluation module is used for the threshold value of mean value, root-mean-square value and the memory module of color reducibility relatively: as if greater than then being substandard product, otherwise, then be qualified products.
Further, described detection system also comprises a display module, is used for the assessment result of evaluation module is shown.(in embodiments of the present invention, described display module is mobile phone display screen)
The detection method of mobile phone cam color reducibility provided by the invention and system, it is taken standard 24 colour atlas by mobile phone cam, obtain first image, change the chromaticity coordinate of each color lump of first image then, obtain the first chromaticity coordinate collection, again the first chromaticity coordinate collection and the standard colorimetric coordinate set that is stored in the mobile phone are compared, obtain the mean value of color reducibility and root-mean-square value and with the mean value of color reducibility and root-mean-square value in default threshold value relatively, obtain testing result: if greater than threshold value, it then is substandard product, otherwise, then be qualified products.Make that the production phase can the more convenient Performance Evaluation that accurately carries out camera, improved production efficiency, reduced production cost.
Be understandable that, for those of ordinary skills, can be equal to replacement or change according to technical scheme of the present invention and inventive concept thereof, and all these changes or replacement all should belong to the protection range of the appended claim of the present invention.