CN1779718A - Visula partitioned drawing device and method for virtual endoscope - Google Patents
Visula partitioned drawing device and method for virtual endoscope Download PDFInfo
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Abstract
A visible blocking - drawing device of virtual endosope consists of input unit, processing unit and output unit. Its blocking - drawing method includes obtaining a continuous two - dimensional section through CT, picking up interested region from obtained section, presenting divided out tissue organ in 3D grid form, picking up central line of model to direct movement of view - point in roaming, carrying out virtual roaming by utilizing model central line and model grid data, recording screen image viewed and browsed by user in form of file.
Description
Technical field
The present invention relates to the observability piecemeal drawing apparatus and the method thereof of the technical field that Medical Image Processing combines with visualization in scientific computing, particularly a kind of virtual endoscope.
Background technology
Recent years, virtual endoscope is widely used in the inspection of human organ.Combine Medical Image Processing and computer graphics techniques, virtual endoscope has little by little replaced conventional endoscope.Compare with conventional endoscope, virtual endoscope is a kind of complete touchless inspection means, it need not to insert foreign matter in the patient body, thereby greatly alleviated patient's misery, simultaneously can also arrive the zone that conventional endoscope can't be checked, viewpoint direction changes easily, can make and once check the data repeated use.
But be accompanied by the develop rapidly of medical imaging device, the resolution of medical image is also more and more higher.Though present computer hardware level has also obtained develop rapidly, is unable to catch up with the growth of data volume always.Specific to the virtual endoscope that we studied, also inevitably run into such problem, show that mainly it is to difficulty that real-time demonstration brought.Virtual endoscope is because roam in human body, and therefore the speed of roaming is to weigh the important indicator of system performance.In general, if the computing machine per second can show 15 width of cloth pictures, human eye promptly can not felt shake.But for virtual endoscope, also be acceptable about per second 5 width of cloth, because it is to be used for medical examination, the doctor need examine, and it is unfavorable on the contrary too soon to change, but too slow and can influence work efficiency.For example all want couple of seconds could show a width of cloth picture the commodity virtual endoscope software on the market (as the Advanced Windows of GE), this is just too slow.In fact this also is the bottleneck place of virtual endoscope software development, and difficult point also is this.
For the speed of accelerating to draw, some typical methods have been proposed in virtual endoscope successively, mainly can be divided into iso-surface patch and volume drawing.
1 iso-surface patch
Extract the geological information of body surface by Marching Cubes method from data fields, and then generate the computer representation (normally triangular plate grid) of the object of observation, iso-surface patch shows based on this.But be accompanied by the develop rapidly of medical imaging device, the resolution of medical image is more and more higher, and this just makes that the dough sheet number that produces is more and more huger.If directly whole dough sheet data are drawn, then roaming does not reach real-time requirement, and this just needs to reduce the drafting amount of dough sheet.Two kinds of methods that improve iso-surface patch speed are arranged at present: grid abbreviation and visibility analysis.
Cao Yong etc. in virtual endoscope, and according to the characteristics of medical data, have done some improvement of using to this method with progressive meshes (progressive grid) the method first Application of Hoppe.The abbreviation of the porch of organ has been done strict restriction, prevents because abbreviation has destroyed the original benefit of opening up of data.Simultaneously some wrong edge contractions have been done the punishment constraint, so that this method is fit to virtual roaming more.Li Guangming combines grid abbreviation and the segmentation relevant with viewpoint to accelerate virtual roaming.According to the characteristics of medical image, by the QEM method of improving error criterion the three-dimensional model after rebuilding to be simplified, the base net lattice that obtain simplifying are noted the mapping relations of original mesh and base net lattice simultaneously; When drawing, the part in the viewpoint is segmented then, and, made it more approach master pattern according to the position on mapping relations adjustment segmentation summit.
Though by the speed that the grid abbreviation can be accelerated to roam, the quality of image can not be guaranteed.In virtual endoscope, can be faster more correctly determine the position of pathology body in order to make the user, the picture quality during roaming should be placed above the other things all the time.In when roaming, because viewpoint is very near with the intestines wall all the time, the later data of any abbreviation all can cause the attenuating of picture quality, and such abbreviation even can cause the disappearance of the little polyp of pathology.Because the inspection environment of endoscope is an enclosed areas, therefore can set up Portal (inlet) and the such structure of Cell (closed region) is carried out visibility analysis by minute block operations.By the flexural property of enteron aisle, Hong has proposed the piecemeal based on center line, when roaming with the spot projection on the Portal to screen coordinate, and by the observability between Z-buffer memory computing block and the piece.Knapp has strengthened the operation of center line piecemeal, has solved the piecemeal at the enteron aisle upwarped district.
2 volume drawing
Some virtual endoscope systems employing virtual video cameras come the video camera in the simulating reality, so adopt ray cast to carry out the imaging of virtual video camera very naturally; Obtain the position and the direction of surface point by surface inspecting method, just can obtain final imaging results by illumination model again.The most frequently used illumination model is the Phone illumination model, and it has taken all factors into consideration absorption, reflection and three kinds of effects of transmission of body surface.The ray cast method is based on the Phone illumination model.By this method, can directly obtain the distance of each detected surface point to optical centre (focus).So, except the image of final generation, can also obtain the surface information and the depth information of scene, this will help being implemented in the roaming of virtual endoscope volume data.And the ray cast method, under the certain condition constraint, irradiation light from showing that internal volume sends, is passed the volume elements of 3-D view with specific perspective geometry shape, generates many surface view.By suitable amending method and perspective display parameter, the virtual surface view that is generated just can be simulated the image that those obtain with true endoscope effectively.
Draw for the real-time sense of reality of finishing the virtual endoscope volume data, when endoscope body is drawn, can use a kind of volume data and dynamically simplify technology.For the drafting of endoscopic images, only need the data relevant with viewpoint are drawn, the data that need to handle only are confined near the viewpoint, and the body of finding a view of volume drawing may be defined as a rectangular pyramid.So each drafting is only had an X-rayed volume drawing to the data in this rectangular pyramid.Because data volume proportion in whole data fields total amount of data of rectangular pyramid is very little, for each drafting, the information outside the rectangular pyramid need not to consider, so be easy to realize real-time demonstration.In addition, Gobetti etc. is applied to virtual endoscope with the texture technology in the high-performance video card.But texture lacks shade, makes the image of roaming lack authenticity.The capacity of texture memory has also limited the data presented amount in addition.J ó zsef uses ray tracing method to judge that empty voxel is to reduce the drafting time.Mehran is subdivided into a lot of voxel pieces with volume data, calculates observability between these voxel block boundary voxels by ray tracing method, then the direct volume drawing method is used for those visible voxel pieces.
In virtual endoscope, in order to make the doctor can be faster more correctly determine the position of pathology body, the picture quality during roaming should be placed above the other things all the time.But directly all polygons of organ grid model are all drawn, then roaming does not reach real-time requirement, and this just needs to reduce the polygon amount of rendering model.Comprehensive above two kinds of method for drafting, the present invention adopts visibility analysis to reduce the polygon quantity of rendering model.
Summary of the invention
The technical matters that desire of the present invention solves is that the roaming acceleration in the virtual endoscope keeps with picture quality and how this technology well is in the same place with combination of hardware.For this reason, the observability piecemeal drawing apparatus and the method thereof that the purpose of this invention is to provide a kind of virtual endoscope.
The present invention is based on the human organ grid model real-time rendering method of the method for visibility analysis and center line.This method is at first carried out smooth treatment to eliminate " camera lens shake " phenomenon in the roaming to center line, makes this center line help piecemeal more simultaneously and handles.According to the rich bent characteristic of enteron aisle and the bifurcated characteristic of tracheae, grid data is carried out piecemeal then by the feature of center line.Compare with the method for partition based on center line in the past, our method of partition is more reasonable.This method is applied to the visibility analysis in the buildings roaming in the virtual endoscope at last, has realized for the first time the observability of bifurcated is calculated and the piecemeal processing.It has not only accelerated the speed of roaming, and the picture quality of roaming is guaranteed.
Virtual endoscope is that computer graphic image is handled and the application of virtual reality technology at medical domain, realize peeping observation in the human body by making up virtual human body model and computing machine display technique, replenish for real physics endoscopy provides function, have great importance clinically.
We at first specify our method in this section, describe it and the contrive equipment that hardware combines then, set forth the concrete execution in step of our method at last.
By in the research virtual endoscope based on the loaming method of visibility analysis, we find that current approach all is that first piecemeal obtains cell and then calculates observability between these cell.Such piecemeal is also unreasonable for observability, because the cell that can cause in some viewpoint when roaming is many, and fewer at the cell of some viewpoint, make roam speed inhomogeneous.Our method is calculated by the observability in the buildings roaming and the characteristics of medical science model combine, and real-time rendering has been provided the solution of oneself.Obtain the initial position of piecemeal by the center line after smooth, in conjunction with the analysis of observability these piecemeal positions are adjusted, making final piecemeal is optimum to observability.
Our observability method for drafting is a kind of popularization of Hong method, determines piecemeal by observability and center line, and such method of partition is generalized to the tracheae roaming with bifurcated.This method comprises four parts: center line is smooth, the foundation of grid decomposition, observability calculating, Cells and Portals.
It mainly is to be used for virtual reality, real-time rendering and and medical image analysis that visibility analysis that we propose and piecemeal are handled.Compare with method of partition in the past, we have proposed 5 criterions of piecemeal for the first time.By these criterions, not only make piecemeal that the standard of supervising has been arranged, and the piecemeal in the similar virtual environment is also had very strong directive significance.
Description of drawings
Fig. 1. the staircase effect synoptic diagram of center line.
Fig. 2. the smooth synoptic diagram of center line.
Fig. 3. the grid decomposing schematic representation.
Fig. 4. the judgement angle comparison diagram of different possibility frontier points.
The boundary surface Portal synoptic diagram of Fig. 5 .Cell.
Fig. 6. observability is calculated synoptic diagram.
Fig. 7. the observability of crotch requires synoptic diagram.
Fig. 8. major branch is done the observability synoptic diagram of going up different portal position.
Fig. 9. definite synoptic diagram of portal position on the branch.
The structural drawing of Figure 10 .cell.
Figure 11. the result schematic diagram of mesh segmentation.
The figure as a result of Figure 12 .portal.
Figure 13. the comparison diagram of piecemeal and the roaming of method of partition not quality.
Figure 14. the observability piecemeal drawing apparatus structural drawing of virtual endoscope of the present invention.
Figure 15. the observability piecemeal method for drafting process flow diagram of virtual endoscope of the present invention.
Figure 16. the observability piecemeal drawing apparatus of virtual endoscope of the present invention and method surface chart thereof.
Embodiment
1 center line is smooth
In virtual endoscope, the stability of camera lens in order to keep roaming needs a level and smooth center line.But path extraction is based on the voxel space, so center line is made up of the point of series of discrete, and this has just produced " staircase effect ", as shown in Figure 1.Come smooth center line by piece-wise linearization, not only can eliminate the minus lap phenomenon, but also can obtain the branch block message between the line segment of center center line.
It is smooth that Bitter adopts the B-SPL that discrete center line is carried out, though the curve that obtains can be good at solving staircase effect, to having little significance of piecemeal, especially for the object of bending and bifurcated.In our method, come smooth center line by piece-wise linearization to center line, not only the minus lap phenomenon can be eliminated, but also the branch block message between the line segment of center can be obtained.
Suppose S{X
1, X
2..., X
nBe meant the point set that central points all on the center line is formed.S{X
1, X
2..., X
mIt is the subclass of one m point among the S.D represents point and the former distance threshold between the point on the center line on the smooth rear center line.Optimum straight-line segment l is meant point set s{X
1, X
2..., X
mProject to l obtain one group of new point set s ' X '
1, X '
2..., X '
m, satisfy max (| X
1-X '
1|, | X
2-X '
2| ..., | X
m-X '
m|)＜D and m are the line segment of maximum number that satisfies the point of this condition.Article one, smooth centre line L is exactly that straight-line segment l by many optimums is formed.Accompanying drawing 2 is the smooth process of center line, and wherein black line is original center line, and red line is through smooth later center line.
When in commission heart linear light was sliding, we had adopted greedy method, and it comprises following two steps:
Step 1: set an initial value n.Point set { the X that links to each other from n front and back of current i point selection
i, X
I+1..., X
I+n.Connect X
iAnd X
I+nObtain initial line segment l, with point set { X
i, X
I+1..., X
I+nProject to obtain on the l another one point set X '
i, X '
I+1..., X '
I+n.
Step 2:distance=|X
j-X '
j|, i＜j＜i+n.
If э is distance＞D, n=n-1 then.Continue step 1, up to distance＜D, m=n.
If is distance＜D, n=n+1 then.Continue step 1, up to э distance＞D, m=n-1.
2 grids decompose
It is the basis that cell and portal set up that grid decomposes.It intersects by cutting planes and grid, and grid is decomposed.In grid decomposes, the most important thing is how to determine to cut apart frontier point and the boundary line of locating grid, accompanying drawing 3 has shown the process that grid decomposes, and cutting planes is the dotted line of left figure, and the red line of right figure is for decomposing the boundary line on the grid of back.
The grid that our method is based on center line decomposes, and at first determines segmentation plane by the point on the center line, but the coordinate information that the center line after smooth is only had a few, so needs the normal vector of calculation level could determine the position of segmentation plane.On the center line after smooth, the normal vector of putting on every section broken line all is the same, and therefore key is a normal vector of asking for tie point between the different line segments.Our computing method are by the normal vector of two central points before and after the tie point is asked on average, thereby obtain the coordinate O and the normal vector V of each central point, and then determine segmentation plane P by S and V.
(P x) has represented distance between some x and the cutting planes P to dis.Grid disassembles and starts from the grid from the selection of the shortest point of cutting planes, and mathematical expression is:
Wherein x be in the grid more arbitrarily.
For the accelerating selection process, can set a bounding box by the radius value on the central point, when net point then need not calculate, in bounding box, then judge whether to be minimum value by top formula outside this bounding box.After having selected initial point A, in order to make the search of frontier point, prevent the generation of " Rao Quan " phenomenon along fixing direction, can set up one is the center with an O, with OA as judging the angle reference frame of initial line just, as shown in Figure 4.
If the frontier point of current selected is the some B in the accompanying drawing 4, then the selection of other points can be determined by following two conditions:
1.
X is the point that links to each other with a B.
2. polar angle must increase.If current polar angle is ∠ AOB, polar angle ∠ AOD and ∠ AOC so
Must be bigger than ∠ AOB, wherein C and D are possible frontier points.
By top Rule of judgment, finally can obtain the represented boundary line of red line in the accompanying drawing 3.
3 observabilities are calculated
In the observability of virtual scene was calculated, grid data often was divided into the Cell of a lot of sealings.By the cell that estimates that current view point can be seen, and only these cell are drawn, can reduce the render time of dough sheet greatly.In addition, do not exist in the virtual endoscope, such as " add a window somewhere, or add a room " such modification problem in the buildings roaming, usually occurring as the problem that needs in the buildings roaming often grid data to be revised.Therefore in our observability method for drafting, the calculating of observability and piecemeal is all finished in pre-service.
Decompose through grid, can obtain the frontier point on each Cell, but these frontier points coplane not.These frontier point projectables are to segmentation plane, obtain the represented irregular polygon ABCDEFGHIJK of accompanying drawing 5.It is very difficult calculating observability by so irregular polygon, replaces this irregular polygon by minimum circumscribed circle in our method.In addition, external fenestra can well be simulated enteron aisle and be eliminated anisotropic influence.
Whether the observability between Cell and the Cell is calculated and can be existed the light that is not subjected to stop to judge by judging between two Cell.Clearly, such light necessarily passes Portal between Cell and the Cell.Accompanying drawing 6 has shown the observability calculation process.At P
nThe cutting planes at place is S
n, n=1,2,3 ...Project (S
n,, P
n) expression P
nProject to cutting planes S
nArea.Visible (C
n, C
m) two Cell C of expression judgement
nAnd C
mBetween observability.If Visible is (C
n, C
m) be TRUE, C then
nAnd C
mBe visible.Otherwise, C
nAnd C
mBe sightless.
Suppose that current viewpoint is positioned at C
1, P
1Be to connect C
1And C
2Portal.Because this portal is the maximum visibility areas of current view point, therefore the area in initial unshielding light zone is P
1Can draw following conclusion by accompanying drawing 6:
Because P
1≠ 0, so Visible (C
1, C
2)=TRUE.P
1 2＝Project(S
2，P
1)。If P
1 2-P
2＞0, Visible (C
1, C
3)=TRUE.Otherwise Visible (C
1, C
3)=FALSE.P
1 3＝Project(S
3，P
1 2)。If P
1 3-P
3＞0, Visible (C
1, C
4)=TRUE.Otherwise Visible (C
1, C
4)=FALSE.
According to above derivation, the observability of any two Cell can both be established.
The foundation of 4 Cells and Portals
Our purpose is in order to reduce the Cell number that current view point is seen when drawing, so choosing of cutting planes position is very important.According to the flexural property of enteron aisle, cutting planes can be chosen in enteron aisle easily, but exists difficulty the choosing of cutting planes of crotch.Compare with the method for partition based on center line in the past, our method has solved piecemeal problem and the size of piece and the equilibrium problem of observability of crotch in conjunction with visibility analysis.
Before how description sets up cell and portal, five piecemeal requirements are described at first:
1. the position of turning point can be used as initial piecemeal position on the center line.
2.cell length must be within certain threshold range.
3. the narrowest position is the optimal location of piecemeal on the enteron aisle.
4. it is invisible mutually that the piecemeal of crotch makes the later cell of cell before the bifurcated and bifurcated.In accompanying drawing 7, make cell1 and cell2, cell3 invisible mutually by piecemeal at crotch.
5.Cell the dough sheet number must surpass certain threshold value.
The foundation of cell and portal is the core of our method, and it comprises following four steps:
1. the position of initialization Portal
Through smooth operation, center line can well instruct piecemeal, and the line segment tie point on institute's own centre line can be as the initial position of portal.
2. the grid of crotch cutting
When handling bifurcated, the position of the portal on major branch is done at first is determined.As requested 1, it is chosen to separate the nearest initial portal position of fork.Calculate the distance between this position and the bifurcation site then, judge whether to meet the demands 2.Determine a scope according to the minimum and maximum length of cell again, near bifurcated, seek the narrowest position of enteron aisle by this scope.Accompanying drawing 8 has shown the influence of the diverse location of the dried portal of going up of major branch to observability.
After being positioned at portal position that major branch does and being determined, next need to determine the position of portal on the branch, and make the portal of this position meet the demands 4.Determine that the position of portal comprises following two steps on the branch:
(1) thick calculating
Directly decompose to determine that in conjunction with observability and grid the position of portal on the branch is very consuming time.Comprise fortunately that each some O on the center line of range information comprises the coordinate information S of this point and this puts the bee-line R on border, can be expressed as O (S, R).In Fig. 4-9, central point O is projected to cutting planes P can obtain a new some O ' (S ', R ').In accompanying drawing 5, each portal all can be expressed as P (S, R), S is the center of this portal, R is the radius of portal.Begin searching from crotch and satisfy distance (O
B' (S
B', R
B'), P (S, R))＜(R
B+ R) and distance (O
C' (S
c' R
C'), P (S, R))＜(R
C+ R) initial position finally can obtain B and C 2 points in the accompanying drawing 9.
(2) accurate Calculation
As shown in Figure 9, the accurate position of crotch can begin to seek from initial position B and the C that slightly calculates.Seek new portal P along two branch pointwise ground
1And P
2, up to P
1And P
2Satisfy Project (P, P
1)-A＜0 and Project (P, P
2Till)-A＜0.Finally can obtain position D and the E of portal on the branch.
3. adjust the position of final portal
The portal invariant position that keeps crotch, comprise that major branch is done and branch on portal.The portal that adjusts other is to satisfy condition 2.
4. storage cell and set up observability table between each cell
Because the face data are stored with half of data structure, therefore be easy to obtain the data of cell between each portal.Each cell also stores other cell that viewpoint can be seen among the current cell in addition.The data structure of Cell as shown in Figure 10.
5 with the installation drawing of combination of hardware
Main practical function of the present invention is in order to reduce the hardware cost of virtual endoscope.All be based on workstation at the virtual endoscope platform of current popular, and the hardware unit of this method institute combination is a PC.Because our method is to calculate by observability to have quickened virtual roaming, therefore general PC just can satisfy doctor's diagnosis requirement.Figure 14 has provided the observability piecemeal drawing apparatus structural drawing of virtual endoscope of the present invention, wherein, a) is the pictorial diagram of device.B) be the block scheme of device.The observability piecemeal drawing apparatus of virtual endoscope, by input media 1, middle treating apparatus 2, output unit 3 is formed, treating apparatus 2 in the middle of input media 1 is connected in, middle treating apparatus 2 is connected in output unit 3, and input media 1, middle treating apparatus 2, output unit 3 are linked in sequence successively.Wherein input media 1 is generally CT/MRI (nuclear magnetic resonance) machine, but also can transmit by computer network.Middle treating apparatus 2 is processing core PCs of this paper technology.3 of output units are display or computer network, can carry out real-time, interactive to current display result by mouse or keyboard, and the operation result with current that can be real-time transfers out by computer network, to carry out remote diagnosis.
The frame diagram and the surface chart of 6 devices
Accompanying drawing 15 has provided the observability piecemeal method for drafting process flow diagram of the virtual endoscope that comprises technology that this paper introduces, and step was 7 steps:
S1, medical image segmentation for convenience in virtual endoscope, collection has special requirement such as virtual intestines mirror to data in meeting, for residue in polyp and the intestines is better made a distinction, to clean patient's enteron aisle in advance, need the per anum injecting gas to make enteron aisle expansion and intramuscular injection smooth muscle relaxant before checking.Emulation gastroscope and for example needs oral an amount of gas producing powder before checking, fully expands gastral cavity, and the intramuscular injection smooth muscle relaxant reduces peristole, and many positions scanning technique guarantees fully to show the details of the different parts of stomach then.Obtain one group of continuous two-dimentional patient slices by medical imaging devices such as CT, MRI or computer network transmission then, and these group data are input to the represented PC part of Figure 14;
S2 carries out registration and smoothing processing to the 2-D data that obtains, and extracts the user's interest zone by region growing or based on the medical image cutting method of level set.Because through the special processing of front, easier being separated in these zones in cutting into slices usually;
S3 and S4 handle simultaneously, utilize marching cube algorithm that the histoorgan that splits is carried out three-dimensional reconstruction, and represent and store with such canonical form of 3D grid;
S5 carries out binaryzation to the result of cutting apart, and with our previously presented DCC algorithm these two-values result is carried out center line and extract the viewpoint the when point on the center line just can be used as roaming;
S6, the piecemeal roaming algorithm that utilizes this paper to propose carries out piecemeal and observability calculating to center line and the 3D grid that obtains, and final result is presented on the computer screen, make things convenient for the user that lesion region is observed with user-friendly interface, and can be further analyzed and observe interesting areas by keyboard and mouse;
S7, the screen picture that will see and browse is noted with the form of file at last, with usefulness for future reference, and can send to far-end by network, so that real-time diagnosis.
Accompanying drawing 16 has shown the virtual roaming platform of realizing according to top framework.The interface comprises three parts: control panel, reference windows and main window.Roam speed can be regulated arbitrarily in control panel, and observation visual angle also can rotate arbitrarily with user friendly observation accompanying drawing 16 and show the virtual roaming platform of being realized according to top framework.Its interface bag.By the introducing of reference windows, the user can know the position at current view point place in real time, the problem of " getting lost " when this has just solved roaming well.
Specific implementation
We have realized method described in the invention with C Plus Plus, and have done experiment on several different data sets.All experiments all are at a P42.4G, the 512MB internal memory, and operating system is to finish on the PC of Windows 2000, the OpenGL graph function storehouse of standard has been used in the display part.
The observability method for drafting is tested on two kinds of data: simple tracheae and complicated tracheae.
Experimental data is set forth among the table 5-2.
The experimental data of table 1. observability method for drafting.
| The dough sheet number | The number of piece | The piecemeal time (second) | The drafting time (second) | |
| Simple data | 26979 | 4 | 109.203 | 0.016 |
| Complex data | 21401 | 10 | 76.891 | 0.015 |
Accompanying drawing 11 has shown the result of mesh segmentation, and original data presentation is in left column, and right row show the later result of piecemeal, the piece that different color representations is different.Based on center line, can obtain the cell of comprehensive observability and dough sheet number.In addition, observability also can be guaranteed in these cell, and this not only accelerates the speed roamed, and can also guarantee the quality of image.Through test, the roam speed of this method has probably improved 2-5 doubly than directly drawing.
Roaming figure with portal is presented at accompanying drawing 12, and the figure on the left side has shown the portal that major branch is done, and right figure shows the portal on the branch.
Accompanying drawing 13 compared based on the roaming image of piecemeal and do not had the roaming image of piecemeal, the left side is no piecemeal, and the right is based on piecemeal.Clearly as can be seen, our method not only can pick up speed, and can also keep the quality roamed.
Claims (5)
1. the observability piecemeal drawing apparatus of a virtual endoscope, it is characterized in that, by the importation, middle processing section, output is formed, treating apparatus in the middle of input media is connected in, middle treating apparatus is connected in output unit, and input media, middle treating apparatus, output unit are linked in sequence successively.
2. according to the observability piecemeal drawing apparatus of the virtual endoscope of claim 1, it is characterized in that input media is the medical data that the CT/MRI machine directly obtains, also the data that can send by computer network.
3. according to the observability piecemeal drawing apparatus of the virtual endoscope of claim 1, it is characterized in that middle treating apparatus is the core, can be PC.
4. according to the observability piecemeal drawing apparatus of the virtual endoscope of claim 1, it is characterized in that output unit is formed, form that can be by display or computer network transmission is with convenient diagnosis.
5. the observability piecemeal method for drafting of a virtual endoscope, its step is as follows:
S1 obtains one group of continuous two dimension slicing by CT, MRI medical imaging devices or Network Transmission, and these group data are input in the processing section;
S2 extracts the user's interest zone by image partition method;
S3, S4 shows the histoorgan that the splits form with 3D grid;
S5, the center line that extracts model the moving of viewpoint when instructing roaming;
S6 carries out virtual roaming by the center line of this method combination model and the grid data of model;
S7 sees the user and the screen picture browsed is noted with the form of file, with usefulness for future reference, and can send to far-end by network, so that real-time diagnosis.
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