CN106056528A - Engineering drawing copyright protection and modification positioning method - Google Patents
Engineering drawing copyright protection and modification positioning method Download PDFInfo
- Publication number
- CN106056528A CN106056528A CN201610379516.0A CN201610379516A CN106056528A CN 106056528 A CN106056528 A CN 106056528A CN 201610379516 A CN201610379516 A CN 201610379516A CN 106056528 A CN106056528 A CN 106056528A
- Authority
- CN
- China
- Prior art keywords
- pel
- watermark
- virtual point
- straight line
- unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 54
- 238000012986 modification Methods 0.000 title abstract 5
- 230000004048 modification Effects 0.000 title abstract 5
- 238000001514 detection method Methods 0.000 claims abstract description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 4
- 238000010586 diagram Methods 0.000 claims description 27
- 230000004807 localization Effects 0.000 claims description 9
- 238000013519 translation Methods 0.000 claims description 8
- 239000000284 extract Substances 0.000 claims description 6
- 230000000694 effects Effects 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
- 238000007689 inspection Methods 0.000 claims 1
- 230000008859 change Effects 0.000 description 8
- 238000013461 design Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 229910002056 binary alloy Inorganic materials 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 241001212149 Cathetus Species 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000003044 adaptive effect Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T1/00—General purpose image data processing
- G06T1/0021—Image watermarking
- G06T1/0042—Fragile watermarking, e.g. so as to detect tampering
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
- G06F21/10—Protecting distributed programs or content, e.g. vending or licensing of copyrighted material ; Digital rights management [DRM]
- G06F21/16—Program or content traceability, e.g. by watermarking
Abstract
The invention discloses an engineering drawing copyright protection and modification positioning method. The method comprises the following steps: all primitives in the engineering drawing are acquired sequentially; according to types of the primitives, virtual points of a corresponding primitive are acquired; according to a virtual point embedding watermark, the primitive is marked, watermarks are embedded sequentially until all primitives are marked; after the engineering drawing is modified, the water mark embedded in each primitive is extracted sequentially, and a watermark sequence after modification is acquired; in the modified watermark sequence, the original watermark sequence is restored according to the watermark appearing frequencies and a relative position relationship; and the original watermark sequence is compared with the modified watermark sequence, a different position is found out, the modified operation on the engineering drawing is recognized according to watermark features of the position, the operation is finally positioned on the engineering drawing, and modification positioning on the engineering drawing is realized. The method uses vulnerability of the watermarks to carry out detection and positioning on modifications in the engineering drawing, and the robustness of the watermarks is used for protecting the copyright of the engineering drawing.
Description
Technical field
The invention belongs to field of information security technology, more particularly, to a kind of engineering drawing copyright protection and amendment location
Method.
Background technology
Along with the universal of computer utility and the development of the Internet collaborative design, product design informationization builds dynamics
Continuing to increase, engineering drawing safety and version quickly detect the attention the most day by day obtaining enterprise customer；Quickly position engineering drawing
Amendment is favorably improved version management efficiency and copyright protection dynamics.
Existing version detection method, extracts the pel in engineering drawing by ObjectARX secondary developing platform,
Then to compare one by one each pel in original engineering drawing and purpose project figure by bidirectional research；By DC (Divide-
And-Conquer) different types of pel during method processes engineering drawing, improves and compares accuracy.But, two kinds of method efficiency are relatively
Low, need original engineering drawing as reference.When pel quantity is bigger, efficiency is especially prominent；Existing engineering drawing version
Open defect is there is in detection method in terms of detection efficiency and accuracy.
A kind of based on virtual point the semi-fragile watermarking embedding grammar of prior art, is applied to work by semi-fragile watermarking
Journey figure amendment location, improves the accuracy of detection, but the method is complicated to the operation of pel, and detection efficiency still needs to be carried
High.
Summary of the invention
For disadvantages described above or the Improvement requirement of prior art, the invention provides a kind of engineering drawing copyright protection and amendment
Localization method, its object is to resist global operation by embedding semi-fragile watermarking in engineering drawing, and local, location is repaiied
Change, thus solve existing engineering drawing version detection method detection efficiency low technical problem.
For achieving the above object, according to one aspect of the present invention, it is provided that a kind of engineering drawing copy-right protection method, based on
Semi-fragile watermarking, specifically includes following steps:
(1) traversal engineering drawing data base, obtains sequence of graphical elements；And each pel in traversing graph metasequence successively, by every two
It is a pel pair that individual adjacent pel is compiled；
(2) pel at engineering drawing is embedded in digital watermarking；Wherein, digital watermark embedding position is according to the kind of pel pair
Select.
Owing to the amendment of engineering drawing can cause the watermark embedded change, by analyzing watermark before engineering drawing is revised
The change of rear generation realizes revising engineering drawing the judgement of operation, and positions amendment；Due to the watermark information embedded
Can restore after engineering drawing is revised, serve engineering group's copyright authentication and the effect of protection, be embedded into engineering drawing
Digital watermarking, plays the effect to engineering drawing copyright protection.
Preferably, above-mentioned engineering drawing copy-right protection method, when two pels that pel is internal are straight line pel, embed
The method of digital watermarking is specific as follows:
(2.1) virtual point V of the first straight line pel AB is obtainedp1Coordinate, and virtual point V of the second straight line pel CDp2
Coordinate,
Wherein,It it is virtual point Vp1Abscissa and vertical coordinate,It it is virtual point Vp2Abscissa
And vertical coordinate；(xa,ya) it is abscissa and the vertical coordinate, (x of the terminal A of the first straight line pel ABb,yb) it is straight line pel AB
The abscissa of terminal B and vertical coordinate, (xc,yc) it is abscissa and the vertical coordinate, (x of the end points C of the second straight line pel CDd,yd) be
The abscissa of the end points D of the second straight line pel CD and vertical coordinate, ENC is virtual point encryption；H for calculate variable, be by with
The decimal digits that family the sets decimal less than 4；
(2.2) ratio between pel is obtained
Wherein LABRefer to the length of straight line pel AB,Refer to the distance between two virtual point；
Ratio r is double-precision floating points, and its binary coding has 64, and the 63rd represents sign bit, the 62nd to 52 table
Showing exponent bits, the 51st to the 0th is mantissa bit；
(2.3) ASCII character of the watermark unit that acquisition plan embeds, and this ASCII character is converted into the binary number of 5,
Replace mantissa the 4th to the 0th totally 5 bit of r with this binary number, embed digital watermarking, it is thus achieved that new pel
Between ratio r '；
(2.4) according to the ratio r between new pel ', obtainWherein,After referring to embed watermark
Distance between two virtual point；
(2.5) by the second straight line pel CD along virtual point Vp1With virtual point Vp2The rectilinear direction translation at placeDistance；Engineering drawing embeds the change in location pass of the variant present straight line pel after watermark and straight line pel
Fasten.
In said method, for the replacement position of r, embedding in mantissa part the 4th (coding after watermark unit conversion accounts for 5)
Enter the impact on r minimum, embed the impact on r mantissa part the 51st maximum, and the exponential part of r and mantissa part are common
Function influence embeds error；
This errorThe changing value of watermark unit virtual point distance, e after wherein Δ q is embeddingqTwo is virtual
The double precision degree floating-point exponent value of the straight length represented by Dian, pos represents watermark unit embedded location；By error expression
Can be seen that eq+ pos impact embeds error；So using dynamic position to embed watermark method, work as eqTime bigger, embedded location pos selects
At less mantissa position；In the range of engineering drawing required precision, pos=25-eq；Work as eqTime bigger, watermark unit embeds
Position pos takes low level, works as eqTime less, watermark unit embedded location pos takes a high position.
Preferably, above-mentioned engineering drawing copy-right protection method, the method for described ASCII character conversion is by each letter
ASCII character deducts the coding that 96 generations are new, obtains 0-25 and represents watermark unit a-z, and wherein the binary system of a is 00000, the two of z
System is 11001；It is 1011111 owing to the ASCII character of English alphabet is converted into binary system more than 95,95, the portion of mantissa of such r
Divide the figure place needing to replace the most, computational accuracy will be reduced, and mantissa's figure place is too much easily subject to destroy.
Preferably, above-mentioned engineering drawing copy-right protection method, when in two pels that pel is internal be straight line pel,
When another is circle diagram unit or circular arc pel, the method embedding digital watermarking is specific as follows:
(2.1) straight line pel AB virtual point V is obtainedp1,
Wherein,It it is virtual point Vp1Abscissa and vertical coordinate, (xa,ya) the horizontal seat of terminal A of straight line pel AB
Mark and vertical coordinate, (xb,yb) it is abscissa and the vertical coordinate of the terminal B of straight line pel AB, ENC is virtual point encryption, and h is
Calculate variable, be the decimal digits the being set by the user decimal less than 4；
(2.2) by circle diagram unit or the virtual point that the center of circle is this pel of circular arc pel, coordinate is
(2.3) ratio between pel is obtained
Wherein, the 51 of double-precision floating points r are mantissa bit to the 0th；
Wherein LABRefer to the length of straight line pel AB,Refer to the distance between two virtual point；
(2.4) ASCII character of the watermark unit that acquisition plan embeds, and this ASCII character is converted into the binary number of 5,
Replacing, with this binary number, 5 bits that the mantissa of r is corresponding, the bit that mantissa is replaced is according to the ratio between pel
The exponent bits of r determines；Embed digital watermarking, it is thus achieved that the new ratio r between pel '；
(2.5) according to the ratio r between new pel ', obtainWherein,After referring to embed watermark
Distance between two virtual point；
(2.6) by circle diagram is first or circular arc pel is along virtual point Vp1With virtual point Vp2The rectilinear direction translation at placeDistance；Engineering drawing variant present straight line pel after embedding watermark is first with circle diagram or circular arc pel
Change in location is closed and is fastened.
The method of above-mentioned embedding digital watermarking, to circle or circular arc pel, directly taking the center of circle is virtual point, on the one hand simplifies meter
Calculating, another aspect is random distribution due to engineering drawing cathetus pel, circle diagram unit and circular arc pel, and a part of virtual point adds
Close, another part is not encrypted, and enhances and cracks difficulty, improves the copyright protection intensity to engineering drawing.
Preferably, above-mentioned engineering drawing copy-right protection method, when in two pels that pel is internal be circle diagram unit or
Circular arc pel, when another is straight line pel, the method embedding digital watermarking is specific as follows:
(2.1) using the center of circle of circle diagram unit or circular arc pel as virtual point Vp1, virtual point Vp1Coordinate is
(2.2) straight line pel AB virtual point V is obtainedp2,
Wherein,It it is virtual point Vp2Abscissa and vertical coordinate, (xa,ya) horizontal stroke of terminal A of straight line pel AB
Coordinate and vertical coordinate, (xb,yb) it is abscissa and the vertical coordinate of the terminal B of straight line pel AB, ENC is virtual point encryption, h
For calculating variable, it it is the decimal digits the being set by the user decimal less than 4；
(2.3) ratio between pel is obtained
Wherein, the 51 of double-precision floating points r are mantissa bit to the 0th；
LABRefer to the length of straight line pel AB,Refer to the distance between two virtual point；
(2.4) ASCII character of the watermark unit that acquisition plan embeds, and this ASCII character is converted into the binary number of 5,
Replacing, with this binary number, 5 bits that the mantissa of r is corresponding, the bit that mantissa is replaced is according to the ratio between pel
The exponent bits of r determines；Embed digital watermarking, it is thus achieved that the new ratio r between pel '；
(2.5) according to the ratio r between new pel ', obtainWherein,After referring to embed watermark
Distance between two virtual point；
(2.6) by straight line pel along virtual point Vp1With virtual point Vp2The rectilinear direction translation at placeAway from
From；Engineering drawing is fastened embedding the change in location pass with circle diagram unit of the variant present straight line pel after watermark.
Preferably, above-mentioned engineering drawing copy-right protection method, when in two pels that pel is internal is circle or circular arc
Pel, when another is for circle or circular arc pel, the method embedding digital watermarking is as follows:
(2.1) center of circle taking the first circle or circular arc pel as the first virtual point, coordinate is
(2.2) center of circle taking the second circle or circular arc pel as the second virtual point, coordinate is
(2.3) ratio between pel is obtained
Wherein, the 51 of double-precision floating points r are mantissa bit to the 0th；
LABRefer to circle diagram unit or the radius of circular arc pel,Refer to the distance between two virtual point；
(2.4) ASCII character of the watermark unit that acquisition plan embeds, and this ASCII character is converted into the binary number of 5,
Replace that the mantissa of r is corresponding with this binary number 5；The bit being replaced in mantissa is according to the finger of the ratio r between pel
Numerical digit determines；Embed digital watermarking, it is thus achieved that the new ratio r between pel '；
(2.5) according to the ratio r between new pel ', obtainWherein,After referring to embed watermark
Distance between two virtual point；
(2.6) the second circle diagram unit or circular arc pel are translated according to the rectilinear direction at two virtual point placesDistance；Engineering drawing closes in the change in location embedded between the variant present circle diagram unit after watermark to be fastened.
For realizing the object of the invention, according to another aspect of the present invention, it is provided that a kind of engineered layout amendment location side
Method, extracts the watermark sequence being modified from the engineering drawing revised, and from the watermark sequence being modified, occurs according to watermark
Frequency and relative position relation restore original watermark sequence；Comparison the two watermark sequence, the position at amendment place, location
Put, specifically include following steps:
(1) from the engineering drawing revised, extract amended watermark sequence W', travel through this watermark sequence W', obtain water
Impression unit wi；
And travel through the watermark unit in amended watermark sequence W', it is combined into according to two watermark unit of adjacent position
Existing frequency, according to described frequency sequential query from high to low, reduction obtains original watermark sequence w；
And set up doubly linked list H according to described original watermark sequence w；I is watermark unit wiNumbering in watermark sequence；
I >=0, i is integer；
(2) by each watermark unit w of amended watermark sequence W'iCompare with the element in doubly linked list H,
Work as wiTerminate to identify identical with original watermark sequence, and wi-1∈ H, then judge that (i+1) individual pel is to last
Pel is the pel being modified, detection of end；
Work as wiTerminate from original watermark sequence to identify different, then judge whether doubly linked list H comprises watermark unit wi；If so,
Then enter step (3), if it is not, then enter step (5)；
(3) by wi-1And wi+1Compare with all elements in doubly linked list H, identify different from element in doubly linked list
Watermark unit wk；
(4) determine whether that i is less than the quantity of watermark unit in watermark sequence W', if so, enter step (5)；If it is not, then tie
Bundle detection；
(5) w is judged whetheriAnd wi-1Broadly fall into doubly linked list H, or judge whether wiAnd wi+1Broadly fall into doubly linked list H；If
It is then to show wiTwo pels be not modified, enter step (6)；If it is not, then enter step (7)；
(6) judge whether j=0, the most then make j=i, take w in described watermark sequence W'iNext watermark unit,
And enter step (4)；If it is not, then enter step (7)；Wherein, j is current wa unit wjThe numbering in watermark sequence；j
>=0, j are integer；
(7) work as i-k=2, then judge that (k+i) is deleted to the pel between i-th pel；As i-k ＞ 2, then judge
(k+i) is modified to the pel between i-th pel；Work as i-k=1, then judge do not have pel to be modified；
Make k=0, in watermark sequence W', take watermark unit wiNext watermark unit, and enter step (4)；Wherein,
K is watermark unit w different from element in doubly linked list that step (3) identifieskNumbering in watermark sequence, k >=0, k is
Integer.
Above-mentioned detection method, not only detection current wa unit wi；Also compare wiNext watermark unit wi-1On or
One watermark unit wi+1；If current wa unit wiIdentical with an element in doubly linked list H, then it is by its adjacent watermark
Unit wi-1、wi+1Compare with the element in doubly linked list H, determine whether pel is modified, reach to prevent the purpose of erroneous judgement.
In general, by the contemplated above technical scheme of the present invention compared with prior art, it is possible to show under acquirement
Benefit effect:
(1) the engineered layout guard method that the present invention provides, is embedded into semi-fragile watermarking in engineered layout；This number
Word watermark will not change the attribute of pel, but can resist global attack, and robustness is preferable；Use containing watermark engineering drawing with
Carry out copyright authentication, it is ensured that engineering drawing safety on network；And in collaborative design, reduce designer at engineering drawing
Institute's time spent in management and version detection, improve design efficiency and safety, meet present Internet advertising distribution collaborative design
Demand, reaches to improve design efficiency, the purpose of guarantee design safety；
(2) the engineered layout guard method that the present invention provides, by the virtual point on adaptive refinement algorithms selection pel；
Judge that the virtual point selected, if appropriate for embedding watermark, if it is not, then adjust parameter, continuing to calculate, being suitable for until obtaining
Embed the virtual point of watermark；Carrying out Hash operation for different parameter inputs, each pel is according to having and only only one
Virtual point；
Calculating to virtual point is encrypted, and enhances the safety of user profile, improves disguise, makes the watermark of embedding
There is higher reliability；When the virtual point calculated is undesirable, then adjust parameter, continue to calculate next virtual point,
Until the virtual point of correct position occurs；Finally, for the pel of different types, algorithm does not the most use self adaptation
Computations, but directly selected characteristic point is as virtual point, such as circle, directly choosing the center of circle is virtual point, circle diagram unit
Engineering drawing is random distribution, so the virtual point of encryption and unencrypted virtual point random distribution, increases and crack difficulty；
(3) the engineered layout guard method that the present invention provides, uses semi-fragile watermarking, and such watermark is single to local
Primitive operation has stronger sensitivity, can position the amendment of engineering drawing local, can quickly judge the type of operation and position
The position of operation, has the advantages that positional accuracy is high, locating speed is fast.
Accompanying drawing explanation
Fig. 1 is the engineering drawing copyright protection that the embodiment of the present invention 1 provides and the watermark embedding principle revising localization method
Schematic diagram；
Fig. 2 is the engineering drawing copyright protection that the embodiment of the present invention 2 provides and the double-precision floating points knot revising localization method
Structure schematic diagram；
Fig. 3 be fact Example 4 of the present invention provide engineering drawing copyright protection and amendment localization method watermark embed flow process show
It is intended to；Wherein, Fig. 3 (a) embeds schematic flow sheet, if 3 (b) is the watermark sequence schematic diagram embedded；
Fig. 4 is the engineering drawing copyright protection that the embodiment of the present invention 3 provides and the schematic flow sheet revising localization method；
Fig. 5 is the schematic diagram extracting amended watermark sequence in the embodiment of the present invention from the engineering drawing revised；
Wherein, Fig. 5 (a) is to extract schematic flow sheet, and Fig. 5 (b) is the watermark sequence schematic diagram extracted；
Fig. 6 is the schematic diagram restoring original watermark information in the embodiment of the present invention from amended watermark sequence.
Detailed description of the invention
In order to make the purpose of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, right
The present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, and
It is not used in the restriction present invention.If additionally, technical characteristic involved in each embodiment of invention described below
The conflict of not constituting each other just can be mutually combined.
As shown in Figure 1, be embodiment 1 provide engineering drawing copy-right protection method in watermark embed principle schematic；
Wherein, AB refers to that straight line pel AB, CD refer to straight line pel CD, Vp1It is the virtual point of straight line pel AB, Vp2It is straight line pel CD
Virtual point, q is the distance between virtual point, and p is the length of straight line pel AB, and s is the length of straight line pel CD, and C'D' is water
New position after straight line pel CD moves after print embedding, straight line pel CD translates along the rectilinear direction at two virtual point places；
Connect two virtual point and obtain virtual line Vp1Vp2；Calculate the length ratio of virtual line length and second pel p
Value r；Watermark unit is embedded in the double-precision floating point type mantissa part of this ratio r；And by second straight line pel CD edge
The rectilinear direction of virtual point translates a segment distance, and translation distance is
As shown in Figure 2, C (wj) it is that watermark unit changes 5 binary codings obtained；Pos is that this watermark unit exists
Embedded location in engineering drawing, with C (wj) replace the corresponding figure place of mantissa part.
Below in conjunction with embodiment, it is specifically described the mistake that in the engineering drawing copy-right protection method that the present invention provides, watermark embeds
Journey；In the present embodiment, two pels are straight line pel, and the method embedding digital watermarking is specific as follows:
(1) watermark information embedded according to plan, obtains watermark sequence W={w, *, w, * ..., w, #}, at this watermark sequence
In, separated by * symbol between * symbol, end up with # symbol；Launch watermark information and obtain W={w1,...,wi,...,wm,*,
w1,...,wi,...,wm,*,...,w1,...,wi,...,wm,#}；
In embodiment, the origin identification of agreement watermark sequence is * symbol, terminates to be designated # symbol；I refers to watermark unit
Numbering；
(2) watermark letters is sequentially embedded in the double-precision floating points mantissa part of ratio, replaces mantissa with watermark
The position of partial response；
As in figure 2 it is shown, r uses double-precision floating points to represent, the ratio r after watermark embedding '=EMB (C (wi),pos,r)；
EMB is imbedding function, C (wj) it is wiEncoded radio；
Deduct the encoded radio of 96 acquisition letters with the ASCII character of letter, the ASCII character of such as a is 96, and its encoded radio is 0,
The encoded radio of ' * ' and ' # ' is respectively 0 and 27；Telescopiny has only to revise 5 in mantissa part；Pos represents and embeds position
Put, pos=25-eq。
As schematically shown in Figure 3, wherein, Fig. 3 (a) is embedding for the engineering drawing amendment localization method flow process that the embodiment of the present invention 3 provides
Enter schematic flow sheet, if 3 (b) is the watermark sequence schematic diagram embedded；In figure, 5 represent the 5th pel, and in figure, 6 represent the 6th figure
Unit, specific as follows:
(1) obtaining the end points that A, B are straight line AB at 2, A, C 2 are the end points of straight line AC, A point coordinates (103.57,
251.43), the coordinate of C point is (459.65,251.43), and the coordinate of B point is (103.57,80.081)；
(2) calculate the virtual point coordinate of straight line AB according to AES according to the coordinate of A, B and C point, its coordinate is Vp5
=(103.57,361.206), the virtual point coordinate of straight line AC, its coordinate is Vp6=(174.786,251.43)；
(3) virtual line V is obtained according to virtual point coordinatep5Vp6LengthAnd calculate straight line AB
Length LAB=549.38；
(4) virtual line V is calculatedp5Vp6Lenth ratio with straight line ABThe double-precision floating point of r
Number representation is
(-1)0x2-3x1.90640906400000000000005684341886080801486968994140625；
Wherein sign bit is 0, and exponential part is-3, and mantissa part is
1.90640906400000000000005684341886080801486968994140625；Being converted into binary coding is
0011111111001110011101101100100010110100001110010101100000010000；
(5) according to pos=25-eq, it is thus achieved that watermark embedded location pos=25-(-3)=28, i.e. watermark are opened from the 28th
Begin to embed；
(6) from the figure 3, it may be seen that in the 5th pel and the 6th pel watermark unit to be embedded be letter ' k ', by letter k '
Being converted to binary coding is 01011；
(7) from the 28th start, replace 5 bits 10 110 next successively with 01011, it is thus achieved that embed after watermark
Ratio r between pel ', the double-precision floating points of r' is
00111111110011100111011011001000010111000011100101011000 00010000 i.e. r'=
0.237999918043613；
(8) by straight line AC according to Vp1Vp2Direction translate a segment distance, translation distance isThe coordinate of some A ' is (103.5700419,251.4300272), and the coordinate of C ' is
(459.6500419,251.4300272), a watermark unit has embedded, as shown in Figure 3.
The engineering drawing amendment localization method flow process that the embodiment of the present invention provides is as schematically shown in Figure 4, specific as follows:
(1) from the engineering drawing revised, amended watermark sequence W' is extracted；As shown in Figure 5；Wherein, Fig. 5 (a) is
Extract schematic flow sheet, first calculate virtual point, then calculate the length of two virtual point and the lenth ratio r of straight line AB, pass through r
Calculate the embedded location of watermark, finally extract corresponding 5 binary codings from the 28th, be ultimately converted to watermark unit
Corresponding letter；Fig. 5 (b) is the watermark sequence schematic diagram extracted；
(2) original watermark information w is restored from amended watermark sequence W', as shown in Figure 6, in step (1)
The amended watermark sequence extracted, the successively watermark unit in traversal watermark sequence, and add up two of adjacent position
The frequency that watermark unit combination occurs, finally as shown in the statistical table in figure, owing to before embedding, the initial watermark unit of regulation is
' * ' symbol, so from ' * ' sign-on, according to the inquiry successively of frequency of occurrences order from high to low, reduction obtains initial condition
Official seal breath is jack；
(3) the watermark information w restored in * symbol and step (2) is combined (i.e. * jack) and set up doubly linked list
H；
(4) element (as shown in Figure 4) in amended watermark sequence W' all with doubly linked list H are traveled through successively
Element compares, and traverses ' * ' symbol, and ' * ' symbol belongs to H, and does not has watermark unit before it, and watermark unit below is
Letter ' j ', it is determined that ' * ' symbol watermark unit is not tampered；
Next traversal ' j ', ' j ' belongs to H, and before it, a watermark unit is ' * ' symbol, and latter one watermark unit is
' a ', ' * ' symbol and ' a ' broadly fall into H, so, ' j ' is not tampered；Same, ' a ' and ' c ' is not the most tampered, note
It is designated as 4 under record；
(5) carrying out successively until traversing ' e ', ' e ' is not belonging to H, and its previous watermark unit ' c ' belongs to H, later
Watermark unit ' m ' is not belonging to H, it is determined that ' e ' is tampered, does not record subscript；
Continuing traversal until traversing ' a ', ' a ' belongs to H, and the watermark unit ' c ' that ' a ' is below belongs to H, it is determined that
' a ' is not tampered, and records and is designated as 8, and (8-4) is more than 3, judges according to the method shown in Fig. 4, the 6th pel and the 7th
Pel is modified；In this embodiment, subscript is watermark unit numbering in watermark sequence.
Above-mentioned detection method not only detects current wa unit wi；Also compare the next watermark list of current wa unit
Unit wi-1Or upper watermark unit wi+1；If current wa unit wiEqual to an element in H, then compare next watermark unit
wi-1With the element in chained list H；Or relatively upper watermark unit wi+1With the element in chained list H, reach to prevent the mesh of erroneous judgement
's.
Explanation of technical terms involved in the present invention is as follows:
Watermark unit, is the unit of watermark information minimum, uses wiRepresent；Watermark unit in embodiment is exactly a word
Female；
Watermark information is made up of some watermark unit, uses w={w1,...,wi,...,wmRepresent, such as w={j, a, c,
k}；
Watermark sequence, is obtained by watermark information extension, represents with W；W={w, *, w, * ..., w, #}, by " * "
Separate, end up with " # ", launch watermark information and obtain W={w1,...,wi,...,wm,*,w1,...,wi,...,wm,*,...,
w1,...,wi,...,wm,#}。
Watermark sequence length is determined by engineering drawing pel quantity, and last w may be imperfect, is to end up with " # " symbol；
New watermark sequence, represents with W', is the watermark sequence extracted engineering drawing after amendment；
Virtual point, each pel can be according to being calculated a virtual point, and this point is divided into two parts pel, but
It is not present in engineering drawing；
Virtual line refers to connect the straight line that two virtual point are formed, and this straight line is not present in engineering drawing；Virtual length
Degree refers to the distance between two virtual point.
As it will be easily appreciated by one skilled in the art that and the foregoing is only presently preferred embodiments of the present invention, not in order to
Limit the present invention, all any amendment, equivalent and improvement etc. made within the spirit and principles in the present invention, all should comprise
Within protection scope of the present invention.
Claims (7)
1. an engineering drawing copy-right protection method, it is characterised in that comprise the steps:
(1) traversal engineering drawing data base, obtains sequence of graphical elements；And each pel in traversing graph metasequence successively, by each two phase
It is a pel pair that adjacent pel is compiled；
(2) adjacent graphical elements at engineering drawing is embedded in digital watermarking；Wherein, embedding algorithm position is according to the kind of pel pair
Class selects；
Described numeral plays the effect of engineering drawing copyright protection, when engineering drawing is illegally distorted, and described digital watermarking changes therewith.
2. engineering drawing copy-right protection method as claimed in claim 1, it is characterised in that in described step (2), when pel is internal
Two pels when being straight line pel, embed the method for digital watermarking and include following sub-step:
(2.1) virtual point V of the first straight line pel AB is obtainedp1Coordinate, and virtual point V of the second straight line pel CDp2Seat
Mark,
Wherein,It it is virtual point Vp1Abscissa and vertical coordinate,It it is virtual point Vp2Abscissa and vertical
Coordinate；(xa,ya) it is abscissa and the vertical coordinate, (x of the terminal A of the first straight line pel ABb,yb) it is the terminal B of straight line pel AB
Abscissa and vertical coordinate, (xc,yc) it is abscissa and the vertical coordinate, (x of the end points C of the second straight line pel CDd,yd) it is second
The abscissa of the end points D of straight line pel CD and vertical coordinate, ENC is virtual point encryption, and h is for calculating variable；
(2.2) ratio between pel is obtained
Wherein LABRefer to the length of straight line pel AB,Refer to the distance between two virtual point；Ratio r is that double precision is floated
Counting, its binary coding includes 64 bits, and the 63rd is sign bit, and the 62nd to 52 is exponent bits, and the 51st to the 0th is tail
Numerical digit；
(2.3) obtain the ASCII character of the watermark unit intending embedding, and described ASCII character is converted into the binary number of 5；With
Described binary number replaces 5 bits that the mantissa of described ratio r is corresponding, embeds digital watermarking, it is thus achieved that between new pel
Ratio r '；Wherein, bit mantissa being replaced determines according to the exponent bits of the ratio r between pel；
(2.4) according to the ratio r between new pel ', obtainWherein,Refer to embed watermark latter two
Distance between virtual point；
(2.5) by the second straight line pel CD along virtual point Vp1With virtual point Vp2The rectilinear direction translation at place
Distance.
3. engineering drawing copy-right protection method as claimed in claim 2, it is characterised in that the method for described ASCII character conversion is, by word
Female ASCII character deducts 96, generates new coding.
4. engineering drawing copy-right protection method as claimed in claim 1, it is characterised in that in described step (2), when pel internal two
In individual pel one be straight line pel, another for circle diagram unit or during circular arc pel, embed the method for digital watermarking include as
Lower sub-step:
(2.1) straight line pel AB virtual point V is obtainedp1,
Wherein,It it is virtual point Vp1Abscissa and vertical coordinate, (xa,ya) straight line pel AB terminal A abscissa and
Vertical coordinate, (xb,yb) it is abscissa and the vertical coordinate of the terminal B of straight line pel AB, ENC is virtual point encryption, and h is for calculating
Variable；
(2.2) by circle diagram unit or the virtual point that the center of circle is this pel of circular arc pel, coordinate is
(2.3) ratio between pel is obtained
Wherein, the 51 of double-precision floating points r are mantissa bit to the 0th；
Wherein LABRefer to the length of straight line pel AB,Refer to the distance between two virtual point；
(2.4) obtain the ASCII character of the watermark unit intending embedding, and this ASCII character is converted into the binary number of 5；With institute
State binary number and replace 5 bits that the mantissa of described ratio r is corresponding, embed digital watermarking, it is thus achieved that between new pel
Ratio r '；Wherein, bit mantissa being replaced determines according to the exponent bits of the ratio r between pel；
(2.5) according to the ratio r between new pel ', obtainWherein,Refer to embed watermark latter two
Distance between virtual point；
(2.6) by circle diagram is first or circular arc pel is along virtual point Vp1With virtual point Vp2The rectilinear direction translation at placeDistance.
5. engineering drawing copy-right protection method as claimed in claim 1, it is characterised in that in described step (2), when pel internal two
In individual pel one be circle diagram unit or circular arc pel, when another be straight line pel, embedding digital watermarking method include as
Lower sub-step:
(2.1) using the center of circle of circle diagram unit or circular arc pel as virtual point Vp1, virtual point Vp1Coordinate is
(2.2) straight line pel AB virtual point V is obtainedp2,
Wherein,It it is virtual point Vp2Abscissa and vertical coordinate, (xa,ya) straight line pel AB terminal A abscissa and
Vertical coordinate, (xb,yb) it is abscissa and the vertical coordinate of the terminal B of straight line pel AB, ENC is virtual point encryption, and h is for calculating
Variable；
(2.3) ratio between pel is obtained
Wherein, the 51 of double-precision floating points r are mantissa bit to the 0th；
LABRefer to the length of straight line pel AB,Refer to the distance between two virtual point；
(2.4) obtain the ASCII character of the watermark unit intending embedding, and this ASCII character is converted into the binary number of 5；With institute
State binary number and replace 5 bits that the mantissa of described ratio r is corresponding, embed digital watermarking, it is thus achieved that between new pel
Ratio r '；Wherein, bit mantissa being replaced determines according to the exponent bits of the ratio r between pel；
(2.5) according to the ratio r between new pel ', obtainWherein,Refer to embed watermark latter two
Distance between virtual point；
(2.6) by straight line pel along virtual point Vp1With virtual point Vp2The rectilinear direction translation at placeDistance.
6. engineering drawing copy-right protection method as claimed in claim 1, it is characterised in that in described step (2), when pel internal two
In individual pel one is circle or circular arc pel, and another is for circle or during circular arc pel, embed the method for digital watermarking include as
Lower sub-step:
(2.1) center of circle taking the first circle or circular arc pel as the first virtual point, coordinate is
(2.2) center of circle taking the second circle or circular arc pel as the second virtual point, coordinate is
(2.3) ratio between pel is obtained
Wherein, the 51 of double-precision floating points r are mantissa bit to the 0th；
LABRefer to circle diagram unit or the radius of circular arc pel,Refer to the distance between two virtual point；
(2.4) ASCII character of the watermark unit that acquisition plan embeds, and this ASCII character is converted into the binary number of 5, use institute
State binary number and replace 5 bits that the mantissa of described ratio r is corresponding, embed digital watermarking, it is thus achieved that between new pel
Ratio r '；Wherein, bit mantissa being replaced determines according to the exponent bits of the ratio r between pel；
(2.5) according to the ratio r between new pel ', obtainWherein,Refer to embed watermark latter two
Distance between virtual point；
(2.6) the second circle diagram unit or circular arc pel are translated according to the rectilinear direction at two virtual point places
Distance.
7. an engineered layout amendment localization method, it is characterised in that following steps:
(1) from the engineering drawing revised, extract amended watermark sequence W', travel through this watermark sequence W', obtain watermark list
Unit wi；
And travel through the watermark unit in amended watermark sequence W', occur according to two watermark unit combinations of adjacent position
Frequency, according to described frequency sequential query from high to low, reduction obtains original watermark sequence w；
And set up doubly linked list H according to described original watermark sequence w；I is watermark unit wiNumbering in watermark sequence；I >=0,
I is integer；
(2) by each watermark unit w of amended watermark sequence W'iCompare with the element in doubly linked list H,
Work as wiTerminate to identify identical with original watermark sequence, and wi-1∈ H, then judge that (i+1) individual pel is to last pel
For the pel being modified, detection of end；
Work as wiTerminate from original watermark sequence to identify different, then judge whether doubly linked list H comprises watermark unit wi；The most then enter
Enter step (3), if it is not, then enter step (5)；
(3) by wi-1And wi+1Compare with all elements in doubly linked list H, identify the water different from element in doubly linked list
Impression unit wk；
(4) determine whether that i is less than the quantity of watermark unit in watermark sequence W', if so, enter step (5)；If it is not, then terminate inspection
Survey；
(5) w is judged whetheriAnd wi-1Broadly fall into doubly linked list H, or judge whether wiAnd wi+1Broadly fall into doubly linked list H；The most then
Show wiTwo pels be not modified, enter step (6)；If it is not, then enter step (7)；
(6) judge whether j=0, the most then make j=i, take w in described watermark sequence W'iNext watermark unit, go forward side by side
Enter step (4)；If it is not, then enter step (7)；Wherein, j is current wa unit wjThe numbering in watermark sequence；J >=0,
J is integer；
(7) work as i-k=2, then judge that (k+i) is deleted to the pel between i-th pel；As i-k ＞ 2, then judge (k+
I) it is modified to the pel between i-th pel；Work as i-k=1, then judge do not have pel to be modified；
Make k=0, in watermark sequence W', take watermark unit wiNext watermark unit, and enter step (4)；Wherein, k is step
Suddenly watermark unit w different from element in doubly linked list that (3) are identifiedkNumbering in watermark sequence, k >=0, k is integer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610379516.0A CN106056528A (en) | 2016-05-31 | 2016-05-31 | Engineering drawing copyright protection and modification positioning method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610379516.0A CN106056528A (en) | 2016-05-31 | 2016-05-31 | Engineering drawing copyright protection and modification positioning method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106056528A true CN106056528A (en) | 2016-10-26 |
Family
ID=57171755
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610379516.0A Pending CN106056528A (en) | 2016-05-31 | 2016-05-31 | Engineering drawing copyright protection and modification positioning method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106056528A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113515727A (en) * | 2019-05-13 | 2021-10-19 | 创新先进技术有限公司 | Picture processing method and device based on block chain |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002259346A (en) * | 2001-02-28 | 2002-09-13 | Ntt Communications Kk | System/device for protecting copyright, recording medium with copyright protection program recorded and copyright protection program |
| CN104166957A (en) * | 2014-06-12 | 2014-11-26 | 厦门合道工程设计集团有限公司 | Method for embedding and extracting vector graph copyright images |
| CN105488434A (en) * | 2015-12-03 | 2016-04-13 | 江苏师范大学 | Mark based vector map completeness authentication method |
-
2016
- 2016-05-31 CN CN201610379516.0A patent/CN106056528A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002259346A (en) * | 2001-02-28 | 2002-09-13 | Ntt Communications Kk | System/device for protecting copyright, recording medium with copyright protection program recorded and copyright protection program |
| CN104166957A (en) * | 2014-06-12 | 2014-11-26 | 厦门合道工程设计集团有限公司 | Method for embedding and extracting vector graph copyright images |
| CN105488434A (en) * | 2015-12-03 | 2016-04-13 | 江苏师范大学 | Mark based vector map completeness authentication method |
Non-Patent Citations (1)
| Title |
|---|
| 陈永府等: "Semi-fragile watermarking for automatic detection of engineering drawing modifications in collaborative design", 《COMPUTER-AIDED DESIGN AND APPLICATIONS》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113515727A (en) * | 2019-05-13 | 2021-10-19 | 创新先进技术有限公司 | Picture processing method and device based on block chain |
| CN113515727B (en) * | 2019-05-13 | 2024-05-07 | 创新先进技术有限公司 | Picture processing method and device based on block chain |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhao et al. | Robust hashing for image authentication using Zernike moments and local features | |
| Amano et al. | A feature calibration method for watermarking of document images | |
| Wang et al. | Reversible fragile watermarking for 2-D vector map authentication with localization | |
| CN108595710B (en) | Rapid massive picture de-duplication method | |
| Raju et al. | Copy-move forgery detection using binary discriminant features | |
| Wang et al. | Reversible fragile watermarking for locating tampered blocks in 2D vector maps | |
| Hosny et al. | Copy‐for‐duplication forgery detection in colour images using QPCETMs and sub‐image approach | |
| Tan et al. | Print-Scan Resilient Text Image Watermarking Based on Stroke Direction Modulation for Chinese Document Authentication. | |
| CN106780287B (en) | Lossless watermarking method based on vector geographic line data organization characteristics | |
| CN105205355A (en) | Embedding method and extracting method for text watermark based on semantic role position mapping | |
| Melkundi et al. | A robust technique for relational database watermarking and verification | |
| CN116385250B (en) | Track data double watermarking method based on robust watermarking and fragile watermarking | |
| CN102855423A (en) | Tracking method and device of literary works | |
| CN101751656B (en) | Watermark embedding and extraction method and device | |
| Bedi et al. | A new watermarking approach for non-numeric relational database | |
| Alkhafaji et al. | Payload capacity scheme for quran text watermarking based on vowels with kashida | |
| Jalil et al. | A novel text watermarking algorithm using image watermark | |
| CN102855424A (en) | Digital fingerprint extraction method and device and literary works identification method and device | |
| CN106056528A (en) | Engineering drawing copyright protection and modification positioning method | |
| Hu et al. | An image based algorithm for watermarking relational databases | |
| CN116805069B (en) | Track data zero watermark generation method, track data zero watermark detection device and storage medium | |
| Singh et al. | Detection of seal and signature entities with hierarchical recovery based on watermark self embedding in tampered digital documents | |
| Bedi et al. | A unique approach for watermarking non-numeric relational database | |
| Sun et al. | Multiple watermarking relational databases using image | |
| CN104866737B (en) | A kind of DEM fragile watermark completeness certification methods for taking features of terrain into account |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20161026 |
|
| WD01 | Invention patent application deemed withdrawn after publication |