CN106327416A - Screen dot watermark method based on printed product - Google Patents
Screen dot watermark method based on printed product Download PDFInfo
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- CN106327416A CN106327416A CN201610720563.7A CN201610720563A CN106327416A CN 106327416 A CN106327416 A CN 106327416A CN 201610720563 A CN201610720563 A CN 201610720563A CN 106327416 A CN106327416 A CN 106327416A
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- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T1/00—General purpose image data processing
- G06T1/0021—Image watermarking
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Abstract
The invention discloses a screen dot watermark method based on a printed product. The screen dot watermark method comprises a watermark embedding step and a watermark extraction step. In the watermark embedding step, a feature area extraction algorithm and a regular jittering screening algorithm are applied to an original image so that a feature area is acquired and a screened image is generated; original watermark information is coded so that watermark information is generated; and a screen dot area is selected in the screened image, and the watermark information is embedded in the screen dot area so that a screen dot image is acquired and a printed product carrying the watermark information is generated. In the watermark extraction step, the image of the printed product carrying the watermark information is acquired, and the feature area is acquired through the feature area extraction algorithm; the image of the feature area is acquired so that the screen dot image is acquired; the watermark information in the screen dot image is extracted; and watermark decoding is performed on the watermark information so that the final value of the watermark information is acquired. The overall effect of the printed product can be guaranteed, and the watermark information can be simply and effectively hidden in the image of the printed product.
Description
Technical field
The present invention relates to printing technology, particularly relate to a kind of site based on leaflet water mark method.
Background technology
China has become as third place in the world big printing big country, and the press output value of China in 2010 has exceeded 600,000,000,000 yuan of people
People's coin, the packaging output value has exceeded 1 trillion yuan RMB, but can not be ignored is improving constantly due to print reproduction technology, and one
Aspect, high-end anti-counterfeiting technology needs to put into hardware device or special printing material, and application cost is too high, it is difficult to for common bag
In the printing of dress, books and periodicals and marketable securities；On the other hand, common anti-counterfeiting technology threshold is relatively low and there may be pollution (such as food
Packaging safety) etc. problem, cause the packages printing of shiploads of merchandise, book and periodical printing counterfeiting, infringement, problem of environmental pollution also compares
Seriously.Therefore, low cost, economic and environment-friendly novel printing product Information Hiding Techniques excellent in the urgent need to research anti-counterfeiting performance.
At present, leaflet Information Hiding Techniques is concentrated mainly in following several ways: (1) utilize special typography and
Material carries out Information hiding, such as: RMB anti-counterfeiting, but owing to its typography of this kind of mode is extremely complex, cost is high, it is difficult to should
In common printed product are false proof；(2) utilize the mode that specialty inks is false proof, such as: anti-forgery ink, but a lot of anti-forgery ink makes
Non-ferrous metal link can be caused to pollute, do not meet current " green printing " requirement；(3) data base's telephone service mode is also deposited
In-convenience in use etc. problem；Anti-counterfeiting printing technology based on digital watermarking has become the focus of current research, but owing to inciting somebody to action
Adjust graph text information to carry out rasterizing continuously to process in the processing procedure generating halftone screen point graph text information, watermark can be had a strong impact on
The quality embedded, thus limit and affect the application in leaflet of this technology to a great extent.Along with information
The development of technology, other have been able to be copied easily, anti-counterfeiting performance such as laser hologram image label anti-counterfeit, anti-counterfeit bar code etc.
Poor.Meanwhile, these anti-counterfeit printing modes above-mentioned are only in the false proof aspect of leaflet, the most do not possess print quality with
Track, circulation supervision and information hidden function.
Leaflet data source before printing can be as piece image, then if whether employing watermarking algorithm can be real
Information hiding on existing leaflet？Image watermark is different according to embedded domain, can be divided into spatial domain and transform domain two class, LSB algorithm
It is a kind of common air space algorithm, will be embedded on the position of impact minimum of each pixel value by watermark bit；Calculate in transform domain watermark
In method, algorithm based on DFT, algorithm based on DCT, algorithm based on DWT can be divided into again, it is achieved thinking is similar, i.e. by becoming
Get the data of transform domain in return, represented the watermark value of embedding by the relativeness controlling particular factor.In recent years, in order to carry
The performance of hi-vision watermark opposing geometric attack, the watermarking algorithm in feature based region becomes more and more popular, and first passes through spy
Levy extracted region algorithm, obtain characteristic area, in this characteristic area, in transform domain, carry out watermark embedding and extraction.
Conventional watermarking algorithm, is primarily directed to digital image file and carries out watermark embedding and extraction, but experience
After printing process, owing to image receives the biggest impact, so being difficult to extract correct watermark information.In order to resist print
Brush or print procedure, need to use anti printing and scanning watermarking algorithm, mainly by passing through some coefficients at transform domain
Relativeness realize watermark embed, such as: the coefficient after dct transform has been carried out special classification according to position, has passed through
After classification, the quantity of each apoplexy due to endogenous wind sign expresses watermark information, enhances the robustness that the opposing of this algorithm is print scanned.
This kind of algorithm can realize resisting print scanned effect, but is primarily present two aspect problems: one is resistant to beat
The effect of print scanning has much room for improvement；Two when being to carry out watermark extracting every time, it is necessary to by dedicated scan instrument entire scan leaflet,
And just can obtain watermark information through multiple processing procedures such as correction, denoising, extractions, so the process of extraction is complicated, to sweeping
Retouching instrument requirement high, may change a scanner, extracting result will be affected.
Above watermarking algorithm, is all to be hidden in raw image files, watermark information without reference to core
Printing process.Before a width leaflet printing, need printing material is carried out prepress treatment, specifically include that color separation and screening, point
Color is by the image of RGB pattern, and color separation is four monochrome images of CMYK；Screening is then that every image is made halftone dot image,
Make forme by halftone dot image, re-use forme and print.And the shade in a kind of monochrome image, then it is by net
Dot percentage in dot image realizes, and percentage ratio is the biggest, then the color presented after printing is the deepest, otherwise color is the most shallow, and
The parameters such as dot shape in halftone dot image, screen line number, angle of halftone screen line, all can produce direct shadow to the visual effect of leaflet
Ring.
Leaflet could print through Screening Image, and Screening Image can contain the biggest quantity of information, such as: often
2540dpi and 175lpi by the standard of Screening Image, i.e. 2540 points of per inch, 175 netting twines of per inch are so flat 1
Then there is 175*175 site on the area of side's inch, 1bit watermark value can be hidden by each site in theory, it is contemplated that with
Step and error control coding, actual watermark capacity can reduce, but still can hide substantial amounts of watermark in halftone dot image
Information.
From the above it can be seen that use traditional digital figure watermark algorithm, watermark information is hidden in numeral
In image file, this kind of algorithm cannot resist printing or the printing process attack to watermark information；Anti printing and scanning watermarking algorithm,
On the one hand having much room for improvement in the print scanned effect of opposing, on the other hand it extracts process complexity, and scanning device is required height；Knot
Close site and carry out Information hiding, be the research aspect most with development potentiality, but if only at e-file category research network
The Information hiding of dot image, image attack and watermark extracting, do not have actual replicability.
Summary of the invention
In view of this, it is an object of the invention to propose a kind of site based on leaflet water mark method, it is possible to ensureing
While the whole structure of leaflet, simple and effective watermark information is hidden in leaflet image.
A kind of based on leaflet the site water mark method provided based on the above-mentioned purpose present invention, including: watermark embeds step
Rapid and watermark extraction step, wherein:
Described watermark embeds step, including:
Original image is used characteristic area extraction algorithm, obtains characteristic area；
Original image is used the screening algorithm of rule shake, generates Screening Image；
Original watermark information is encoded, generates watermark information；
In described Screening Image, select the dot area corresponding with described characteristic area；Revise in described dot area
Site feature, by described watermark information embed described dot area, it is thus achieved that embed watermark information halftone dot image；
Use the halftone dot image of described embedding watermark information, generate the leaflet being loaded with watermark information；
Described watermark extraction step, including:
Use image capture device, be loaded with the image of the leaflet of watermark information described in collection, and carried by characteristic area
Take algorithm, obtain described characteristic area；
Gather the image of described characteristic area further, it is thus achieved that the halftone dot image of described embedding watermark information；
Extract the described watermark information in the halftone dot image of described embedding watermark information；
Described watermark information is carried out watermark decoding, it is thus achieved that the end value of watermark information.
In some embodiments, described to original image use characteristic area extraction algorithm, obtain characteristic area concrete
Including:
By Harris Robust Algorithm of Image Corner Extraction, extract in original image and obtain some characteristic points；
With described characteristic point as the center of circle, raw conglobate described characteristic area.
In some embodiments, described by Harris Robust Algorithm of Image Corner Extraction, original image extracts acquisition some
Characteristic point specifically includes:
In original image, calculate the eigenvalue in field, every some place, obtain an eigenvalue matrix；
In all of eigenvalue, maximizing, it is designated as fmax；
Being multiplied by a predetermined coefficient A with fmax, screen threshold value T as characteristic point, characteristic point screening threshold value T is expressed as: T=
fmax*A；
Choose all eigenvalues point more than T, as described characteristic point, by all described characteristic points retained according to spy
Value indicative size is ranked up.
In some embodiments, described with described characteristic point as the center of circle, raw conglobate described characteristic area specifically wraps
Include:
Start to generate characteristic area from the characteristic point that eigenvalue is big successively；The radius of described characteristic area is according to watermark information
Embedding capacity and the number of repetition of watermark information determine；
In current signature region, if covering other characteristic points, then delete other capped characteristic points.
In some embodiments, the described screening algorithm that original image is used rule shake, generate Screening Image tool
Body includes:
Generating the threshold matrix of screening, then original image is stretched to target resolution, threshold matrix is with tiling simultaneously
The mode replicated expands to target resolution, generates the threshold binary image of target resolution, by the original image after stretching and threshold figure
As comparing, generate Screening Image.
In some embodiments, the site feature in the described dot area of described amendment, described watermark information is embedded
Described dot area also includes:
In described dot area, determine that M*M site is one piece of watermark region；Wherein, M sets according to described image acquisition
Standby acquisition range determines；
Described watermark information is embedded, by the site of edge in the exterior domain of described watermark region in described watermark region
It is set to special site and embeds synchronizing information；Described synchronizing information is for indicating the position of described watermark region.
In some embodiments, the tool of the described watermark information in the halftone dot image of described extraction described embedding watermark information
Body includes:
The halftone dot image of the described embedding watermark information collecting described collecting device carries out automatic threshold segmentation, obtains
Bianry image after segmentation；
Obtain maximum radius value by half drive matrix, in conjunction with maximum radius value and seed filling, obtain described dot area
Interior center, each site, determines the position of described special site；
Extract the described synchronizing information in described special site, determine the position of described watermark region；
Extract the described watermark information in site in described watermark region.
In some embodiments, described image capture device is USB camera, and described USB camera at least has 180
Image magnification again.
From the above it can be seen that site based on the leaflet water mark method that the present invention provides, watermark information is hidden
Ensconce the subregion of Screening Image.When watermark embeds, use characteristic area selection algorithm, from original image, obtain feature
Region, carries out screening to image, in the halftone dot image region corresponding with characteristic area, is positioned at dot area edge by amendment
Site feature embed synchronizing information, by the site feature in amendment dot area, it is achieved watermark information is hidden；Extracting water
During print, user uses mobile platform to gather leaflet image, uses characteristic area acquisition algorithm, obtains the characteristic area on leaflet
Territory, gathers halftone dot image on the area, obtains dot area synchronizing information, in each dot area, according to site feature,
Extract watermark information.By method of the invention, it is possible to ensure leaflet whole structure while, simple and effective by water
Official seal breath is hidden in leaflet image.
Accompanying drawing explanation
In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
In having technology to describe, the required accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only this
Some embodiments of invention, for those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to
Other accompanying drawing is obtained according to these accompanying drawings.
Fig. 1 is site based on the leaflet water mark method flow chart of the embodiment of the present invention；
Fig. 2 (a) is original image (Lena)；
Fig. 2 (b) has been the original image after characteristic area extracts；
Fig. 2 (c) is the original image (Lena) Screening Image after screening processes；
Fig. 2 (d) is it is observed that the image of dot shape after in Fig. 2 (c), encircled is amplified.
Detailed description of the invention
For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with specific embodiment, and reference
Accompanying drawing, the present invention is described in more detail.
Embodiments provide a kind of site based on leaflet water mark method.With reference to Fig. 1, for the embodiment of the present invention
Site based on leaflet water mark method flow chart.
Described site based on leaflet water mark method, embeds step 101 and watermark extraction step 102 including watermark.Its
In, watermark embeds step 101 for being embedded in original image by watermark information and generating the leaflet being loaded with watermark information；Water
Print extraction step 102, for the leaflet being loaded with watermark information is read out process, extracts watermark information therein.Specifically
:
Watermark embeds step 101, including:
Step 1011, to original image use characteristic area extraction algorithm, obtain characteristic area.
In this step, in original image, use characteristic area extraction algorithm to obtain characteristic area, i.e. first pass through characteristic point
Detection, obtains multiple characteristic point in piece image.In the present embodiment, described feature point extraction algorithm selects Harris angle point
Extraction algorithm.General, the angle point number obtained in piece image is the most, needs to carry out shining choosing to these angle points, first
Removing angle point close together, screen further according to characteristic strength, several angle points that selection intensity is bigger, with each feature
One circular characteristic area of feature centered by Dian, the radius value of the characteristic area of this circle obtains according to characteristic strength.
Concrete, the screening of characteristic point and the determination process of characteristic area include:
1) in view picture original image, calculate the eigenvalue in field, every some place, obtain an eigenvalue matrix.
2) in all of eigenvalue, maximizing, it is designated as fmax, this is the maximum of entire image eigenvalue.
3) being multiplied by a predetermined coefficient A with fmax, screen threshold value T as characteristic point, characteristic point screening threshold value T is expressed as: T
=fmax*0.7.In the present embodiment, predetermined coefficient A is 0.7, then characteristic point screening threshold value T=fmax*0.7.Described default system
Number A is an experiment value, different image patterns, and the value of predetermined coefficient A is different.
4) all eigenvalues are more than the point of T, as the characteristic point remained, these characteristic points are big according to eigenvalue
Little it is ranked up.
5) start to determine characteristic area from the characteristic point that eigenvalue is big successively, the radius of characteristic area, such as: r=50, half
Size watermark the to be considered embedding capacity in footpath and watermark number of repetition, every block feature region embeds whole watermarks, each
Characteristic area repeats to embed；
If r is big, then, in entire image, characteristic area quantity is few, but each characteristic area is big, and the most each region can be embedding
The watermark capacity entered is big, but it is few to repeat to embed watermark number of times；
Otherwise, r is little, then in entire image, characteristic area quantity is many, but each characteristic area is little, and the most each region is permissible
The watermark capacity embedded is little, but it is big to repeat to embed watermark number of times.
6) in current signature region, if covering other characteristic points, then other capped characteristic points are deleted.
Through step 1)-6) after, view picture original image is left several characteristic area.
Illustrate as a example by Lena picture, with reference to Fig. 2 (a) and Fig. 2 (b)；Wherein, Fig. 2 (a) is original image (Lena), Fig. 2
B () has been the original image after characteristic area extracts.Visible, after feature extraction, obtain 7 validity feature regions,
The blue thick line circle of the characteristic area including Lena eyes of center position marks.
Step 1012, the screening algorithm shaking original image use rule, generate Screening Image.
In this step, use the screening algorithm of rule shake, firstly generate the threshold matrix of screening, then by original figure
As being stretched to target resolution, threshold matrix expands to target resolution in the way of tiling duplication simultaneously, generates target and differentiates
The threshold binary image of rate, compares the original image after stretching with threshold binary image, generates image after screening.
Step 1013, by original watermark information encode, generate watermark information.
In this step, original watermark information is carried out coded treatment, generate the watermark information for embedding leaflet.Example
As, in the dot area of a 5*5, the site being positioned at edge indicates synchronizing information, and the dot area of residue 3*3 represents watermark
Value, in 9 sites, represents 0 and 1 with difformity site, can represent 9bit data, these data are to original watermark respectively
Information carries out coding and obtains, particular make-up: the Bose-Chaudhuri-Hocquenghem Code to original watermark information employing (7,4,1) of 4bit, it may be assumed that original letter
Breath 4bit, coding obtains 7bit, and error correcting capability is 1bit, additionally uses 2bit error-detecging code.Aforesaid original watermark information encodes
Method can be extended to different size site watermark region, such as 7*7 or 9*9.
Step 1014, in described Screening Image, select the dot area corresponding with described characteristic area；Revise described net
Site feature in some region, embeds described dot area by described watermark information, it is thus achieved that embed the halftone dot image of watermark information.
Through abovementioned steps by original image by screening process, after generating Screening Image, in this step, with artwork
The dot area that middle characteristic area is corresponding, realizes watermark by amendment site feature and embeds.With reference to Fig. 2 (c) and Fig. 2 (c)；Its
In, the Screening Image that Fig. 2 (c) is original image (Lena) after screening processes, in figure with circle represent in Screening Image with
The dot area that in original image, characteristic area is corresponding.Fig. 2 (d) is after encircled amplification it is observed that site in Fig. 2 (c)
The image of shape, it can be seen that there is the site of square and circular two kinds of shapes in this region, site feature is by screening
Process control.Owing to, in watermark extraction step, (image capture device used in the present embodiment is for taking the photograph for image capture device
As head) each width leaflet image gathered can be only the sub-fraction of leaflet, so must solve to embed watermark region
Stationary problem, i.e. gathering in image, determined the scope of one piece of watermark region by some special sites, implement process
Including:
(1) scope of watermark region is determined
Selecting M*M site is one piece of watermark region, and M is determined by the piece image region of camera collection, such as 5*5.
(2) synchronization of watermark region
The width leaflet topography that photographic head gathers every time, can be only the sub-fraction of leaflet, for solving to embed
The stationary problem of watermark region, needs to embed synchronizing information in the watermark of site, i.e. one piece of site watermark region being square
In, by the feature indication synchronizing information of site, edge, and select three angles to use special site to represent from four angles, choosing
The purpose selecting three angles is to contain directional information.When selecting special site, it may be considered that special dot area, or
Special dot shape.
Step 1015, use the halftone dot image of described embedding watermark information, generate the leaflet being loaded with watermark information.
Through abovementioned steps, obtain embedding the halftone dot image of watermark information, in this step, this embedding watermark can be used
The halftone dot image of information generates the leaflet being loaded with watermark information.Want the watermark letter extracting in the leaflet being loaded with watermark information
During breath, then need to perform described watermark extraction step 102.
Watermark extraction step 102, including:
Step 1021, use image capture device, be loaded with the image of the leaflet of watermark information described in collection, and by spy
Levy extracted region algorithm, obtain described characteristic area.
Halftone dot image after embedding watermark generates leaflet by printing, if user's watermark information to be extracted, it is necessary to
Watermark is extracted, for telling the position in user characteristics region, it is possible to use common camera collection is printed in the range of characteristic area
Product image, by characteristic area extraction algorithm, obtains characteristic area.Here, user operation for convenience, can be by characteristic area
Extraction procedure, is transplanted on mobile platform, such as: use mobile phone to take pictures leaflet, and photograph image extracts characteristic area, and
Screen marks characteristic area position.
In actual applications, if realizing the characteristic area extraction algorithm of image on Android mobile platform, need
Programming realization on intelligent platform, it is necessary first to combine photographic head programming, it is possible to obtain the current view data gathered；Then pass through
Algorithm extracts characteristic area, for the image processing algorithm that early stage C language can be used to realize, can use android-jni
Technology is transplanted, will C language realize image processing function, be packaged obtaining a .c file according to particular requirement,
And writing Android.mk file, compiled by NDK in cygwin, generate a .so library file, this file realizes can
So that Android engineering to use.
The image of step 1022, the further described characteristic area of collection, it is thus achieved that the halftone dot image of described embedding watermark information.
In the present embodiment, use the USB camera with enough amplifications, the leaflet be loaded with watermark information is adopted
Collection image, the image at this moment collected can be leaflet small part, can comprise the dot area of some.Wherein,
When being normally applied, conventional USB camera uses 180 times or 540 times of camera lenses；Use 180 times of camera lenses, the piece image of collection
In, site number is more, but sharpness of dots is slightly worse；Using 540 times of camera lenses, in the piece image of collection, site number is less,
But sharpness of dots is good；The selection standard of the amplification of camera lens is i.e.: ensure to comprise complete being embedded with in piece image
The region of synchronizing information, is embedded with the size in the region of synchronizing information, determines according to coded format and watermark data.
Step 1023, the described watermark information extracted in the halftone dot image of described embedding watermark information.
On the characteristic area of leaflet, use this regional network dot image of camera collection gathering site, sequentially pass through
Automatic threshold segmentation, dot location location, watermark region location, watermark information extract multiple processing procedures and extract watermark information,
The process of implementing includes:
(a) automatic threshold segmentation
The halftone dot image of the described embedding watermark information collecting described collecting device carries out automatic threshold segmentation, obtains
Bianry image after segmentation.
B () dot location positions
Obtain maximum radius value by half drive matrix, in conjunction with maximum radius value and seed filling, obtain described dot area
Interior center, each site, determines the position of described special site.
C () watermark region positions
In the image collected, by extracting the position of feature site, determine the position at 3 angles of watermark region, by 3
The position at individual angle and the position of other sites, edge, it may be determined that the scope of watermark region, if the scope of watermark region is complete
In present image, then the current image gathered meets the requirements, and can carry out watermark extracting；If in current acquired image, look for
Less than 3 feature sites, or watermark region scope is not exclusively in present image, then present image can not carry out follow-up water
Print is extracted.
D () extracts watermark information
In the range of watermark region, according to dot shape, obtain that each site represents 0,1 yard, i.e. extracts described water
Described watermark information in site in print region.
Step 1024, described watermark information is carried out watermark decoding, it is thus achieved that the end value of watermark information.
Result is first carried out error detection, without mistake being detected, then it is carried out BCH decoding, thus obtain watermark letter
The end value of breath.
As seen from the above-described embodiment, the present invention provide site based on leaflet water mark method, in Screening Image with
The dot area that artwork characteristic area is corresponding carries out Information hiding, can shorten watermark and embed the time, reduces watermark and embeds whole
Width Screening Image causes and significantly affects.Meanwhile, embed the watermark information with synchronizing information one piece of dot area, mainly pass through
Some special sites of watermark region scope realize, so when extracting watermark, as long as in the leaflet halftone dot image collected,
Comprise one piece of complete watermark region, then can extract efficient watermark information.Additionally, use mobile device to gather leaflet
Image, by characteristic area extraction algorithm, obtains characteristic area, and marks characteristic area position on screen.This part is permissible
Realizing on a mobile platform, watermark extracting equipment is simple, it is not necessary to special professional equipment.
Those of ordinary skill in the field are it is understood that the discussion of any of the above embodiment is exemplary only, not
It is intended to imply that the scope of the present disclosure (including claim) is limited to these examples；Under the thinking of the present invention, above example
Or can also be combined between the technical characteristic in different embodiments, step can realize with random order, and exists such as
Other change of the many of the different aspect of the upper described present invention, in order to concisely they do not provide in details.
Embodiments of the invention be intended to fall into all such replacement within the broad range of claims,
Amendment and modification.Therefore, all within the spirit and principles in the present invention, any omission of being made, amendment, equivalent, improvement
Deng, should be included within the scope of the present invention.
Claims (8)
1. site based on a leaflet water mark method, it is characterised in that including: watermark embeds step and watermark extracting step
Suddenly, wherein:
Described watermark embeds step, including:
Original image is used characteristic area extraction algorithm, obtains characteristic area；
Original image is used the screening algorithm of rule shake, generates Screening Image；
Original watermark information is encoded, generates watermark information；
In described Screening Image, select the dot area corresponding with described characteristic area；Revise the net in described dot area
Point feature, embeds described dot area by described watermark information, it is thus achieved that embed the halftone dot image of watermark information；
Use the halftone dot image of described embedding watermark information, generate the leaflet being loaded with watermark information；
Described watermark extraction step, including:
Use image capture device, be loaded with the image of the leaflet of watermark information described in collection, and extract calculation by characteristic area
Method, obtains described characteristic area；
Gather the image of described characteristic area further, it is thus achieved that the halftone dot image of described embedding watermark information；
Extract the described watermark information in the halftone dot image of described embedding watermark information；
Described watermark information is carried out watermark decoding, it is thus achieved that the end value of watermark information.
Method the most according to claim 1, it is characterised in that described to original image use characteristic area extraction algorithm,
Acquisition characteristic area specifically includes:
By Harris Robust Algorithm of Image Corner Extraction, extract in original image and obtain some characteristic points；
With described characteristic point as the center of circle, raw conglobate described characteristic area.
Method the most according to claim 2, it is characterised in that described by Harris Robust Algorithm of Image Corner Extraction, in original graph
Extract the some characteristic points of acquisition in Xiang to specifically include:
In original image, calculate the eigenvalue in field, every some place, obtain an eigenvalue matrix；
In all of eigenvalue, maximizing, it is designated as fmax；
Being multiplied by a predetermined coefficient A with fmax, screen threshold value T as characteristic point, characteristic point screening threshold value T is expressed as: T=
fmax*A；
Choose all eigenvalues point more than T, as described characteristic point, by all described characteristic points retained according to eigenvalue
Size is ranked up.
Method the most according to claim 3, it is characterised in that described with described characteristic point as the center of circle, raw conglobate institute
State characteristic area to specifically include:
Start to generate characteristic area from the characteristic point that eigenvalue is big successively；Embedding according to watermark information of the radius of described characteristic area
The number of repetition entering capacity and watermark information determines；
In current signature region, if covering other characteristic points, then delete other capped characteristic points.
Method the most according to claim 1, it is characterised in that the described screening calculation that original image is used rule shake
Method, generates Screening Image and specifically includes:
Generating the threshold matrix of screening, then original image is stretched to target resolution, threshold matrix is with duplication of tiling simultaneously
Mode expand to target resolution, generate the threshold binary image of target resolution, the original image after stretching entered with threshold binary image
Row compares, and generates Screening Image.
Method the most according to claim 1, it is characterised in that the site feature in the described dot area of described amendment, will
Described watermark information embeds described dot area and also includes:
In described dot area, determine that M*M site is one piece of watermark region；Wherein, M is according to described image capture device
Acquisition range determines；
In described watermark region, embed described watermark information, the site of edge in the exterior domain of described watermark region is arranged
For special site and embed synchronizing information；Described synchronizing information is for indicating the position of described watermark region.
Method the most according to claim 6, it is characterised in that in the halftone dot image of described extraction described embedding watermark information
Described watermark information specifically include:
The halftone dot image of the described embedding watermark information collecting described collecting device carries out automatic threshold segmentation, is split
After bianry image；
Maximum radius value is obtained by half drive matrix, in conjunction with maximum radius value and seed filling, each in obtaining described dot area
Center, site, determines the position of described special site；
Extract the described synchronizing information in described special site, determine the position of described watermark region；
Extract the described watermark information in site in described watermark region.
8. according to the method described in claim 1-7 any one, it is characterised in that described image capture device is USB shooting
Head, described USB camera at least has the image magnification of 180 times.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108615218A (en) * | 2018-05-02 | 2018-10-02 | 北京印刷学院 | The printing quantum dot method of detecting watermarks of pseudo-random information spatial domain modulation |
| CN109274855A (en) * | 2018-07-31 | 2019-01-25 | 北京印刷学院 | A kind of (k, n) halftoning visual encryption method based on characteristic area |
| CN112848727A (en) * | 2021-01-07 | 2021-05-28 | 北京印刷学院 | Screening method, printing method, system and device for image halftone color generation |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101923701A (en) * | 2010-07-19 | 2010-12-22 | 西安建筑科技大学 | Anti-counterfeiting authentication method of anti-counterfeiting image of printed matter based on digital watermarking technology |
| CN103065073A (en) * | 2013-01-25 | 2013-04-24 | 山东大学 | Anti-fake method for digital print based on digital watermark technology |
| CN103247016A (en) * | 2013-04-19 | 2013-08-14 | 上海理工大学 | Digital watermarking anti-counterfeiting method and system based on artistic screening |
| CN103854249A (en) * | 2013-12-28 | 2014-06-11 | 辽宁师范大学 | Digital image watermarking method based on local index torque characteristic |
-
2016
- 2016-08-24 CN CN201610720563.7A patent/CN106327416B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101923701A (en) * | 2010-07-19 | 2010-12-22 | 西安建筑科技大学 | Anti-counterfeiting authentication method of anti-counterfeiting image of printed matter based on digital watermarking technology |
| CN103065073A (en) * | 2013-01-25 | 2013-04-24 | 山东大学 | Anti-fake method for digital print based on digital watermark technology |
| CN103247016A (en) * | 2013-04-19 | 2013-08-14 | 上海理工大学 | Digital watermarking anti-counterfeiting method and system based on artistic screening |
| CN103854249A (en) * | 2013-12-28 | 2014-06-11 | 辽宁师范大学 | Digital image watermarking method based on local index torque characteristic |
Non-Patent Citations (2)
| Title |
|---|
| JONATHAN WEINHEIMER,等: "Towards a robust feature-based watermarking scheme", 《PROCEEDINGS OF IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCEEDING》 * |
| 闻爱华: "基于半色调图像的抗打印扫描数字水印算法研究", 《中国优秀硕士学位论文全文数据库》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108615218A (en) * | 2018-05-02 | 2018-10-02 | 北京印刷学院 | The printing quantum dot method of detecting watermarks of pseudo-random information spatial domain modulation |
| CN108615218B (en) * | 2018-05-02 | 2022-02-15 | 北京印刷学院 | Printed quantum dot watermark detection method based on pseudo-random information spatial modulation |
| CN109274855A (en) * | 2018-07-31 | 2019-01-25 | 北京印刷学院 | A kind of (k, n) halftoning visual encryption method based on characteristic area |
| CN112848727A (en) * | 2021-01-07 | 2021-05-28 | 北京印刷学院 | Screening method, printing method, system and device for image halftone color generation |
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