CN102611822A - Projector and projection image rectifying method thereof - Google Patents

Abstract

The invention discloses a projector and a projection image rectifying method thereof. The projection image rectifying method includes: taking images of a projection area projected on a display screen by the projector through a taking module and obtaining images; determining corresponding geometric rectifying parameters by a rectifying module according to the projection area in the pictures; computing and converting original images to be projected by utilizing geometric rectifying parameters to obtain rectified images; and projecting the rectified images onto the display screen by the projection module. By analyzing the projection area in the images to perform geometric rectifying process or color rectifying process, so that rectifying operation can be realized without preset images with certain features, and process of rectifying projection images is simplified.

Description

Projecting apparatus and projected picture correcting method thereof

Technical field

The present invention relates to shadow casting technique, relate in particular to equipment and method that projected image is proofreaied and correct.

Background technology

Projecting apparatus is a kind of projection arrangement that is used on screen enlarged and displayed image, has been widely used at present in demonstration and the home theater.For example, be used for meeting room demonstration and on large-screen, watch film through connecting equipment such as DVD player in the family.

If the optical axis of projecting apparatus and screen surface out of plumb promptly become an angle of inclination with screen surface, can cause then that images displayed distorts on the screen surface.For fault image is proofreaied and correct, can regulate projecting apparatus at the inclination angle of level and vertical direction, with correcting orthographic projection image through the screw under the projecting apparatus seat.Can this manual adjustment mode, it is very inconvenient to make projecting apparatus use.

For this reason, a kind of projecting apparatus with automatic correcting orthographic projection image function is provided in the prior art, as shown in Figure 1, comprising: correcting unit, projecting cell, angular transducer unit.Angular transducer unit in the projecting apparatus calculates the angle of inclination of projected image in level and vertical direction automatically; Proofread and correct projected image through projecting cell at the level that correcting unit calculates according to the angular transducer unit and the angle of inclination of vertical direction.The complicated part of this method is: the angular transducer unit is made up of range sensor and angle calculation unit; Range sensor need obtain on the screen surface a plurality of measurement points apart from the distance of projecting apparatus, thereby angle calculation unit is according to the angle of inclination of the gentle vertical direction of measuring of distance calculation water outlet.A plurality of measurement points then need project predetermined picture on the screen apart from the distance of projecting apparatus on the screen surface in order to obtain.And this method also has higher hardware cost owing in projecting apparatus, be provided with angular transducer.

In addition, the another kind of projecting apparatus that is provided with camera in the prior art can utilize camera to take the correction that projected image is realized projected image.But the automatic bearing calibration of these projecting apparatus at present also need be in the process of proofreading and correct, some predetermined special images of projection.For example, predetermined special image can be one group of picture with edge feature: background is a black, and is evenly distributed along the picture edge with white spherical dot matrix.After predetermined picture was projected to screen surface, camera was taken projected image, and calculated distortion according to edge feature, and proofreaied and correct on this basis.Though this method does not need built-in angular transducer, has reduced hardware cost,, in trimming process, still need the projection predetermined picture, make trimming process comparatively complicated.

In sum, can realize the projecting apparatus of automatic correcting orthographic projection image at present, in carrying out the projected image trimming process, all need some predetermined picture of projection, this makes trimming process more loaded down with trivial details.And, after accomplishing correction, in the process of carrying out normal projection; If the projected image distortion, then because can't the projection predetermined picture, projecting apparatus can not be discerned the projected image of distortion automatically; Also just can't proofread and correct once more automatically, only if carry out manual intervention.The projecting apparatus that is the automatic correcting orthographic projection image of prior art can not be realized real-time automatic correcting orthographic projection image.

Summary of the invention

The embodiment of the invention provides a kind of projecting apparatus and projected picture correcting method thereof, in order to simplify the method for automatic correcting orthographic projection image.

According to an aspect of the present invention, a kind of projected picture correcting method is provided, has comprised: by photographing module the view field that projecting apparatus projects on display screen has been taken, obtain photographic images; After correction module receives said photographic images,, determine corresponding geometric correction parameter according to the view field in the said photographic images; And use said geometric correction parameter that the original image that needs projection is made operation transform, the image after obtaining proofreading and correct; By the image projection of projection module after with said correction to display screen.

Preferably, said correction module is determined corresponding geometric correction parameter and is specially according to the view field in the said photographic images: said correction module is determined corresponding geometric correction parameter according to the position coordinates on four summits of said view field.

Preferably; The position coordinates on said four summits according to said view field is determined corresponding geometric correction parameter, comprising: according to the position coordinates on four summits of said view field; And the position coordinates of proofreading and correct four summits of rectangle, calculate the geometric correction parameter.

Preferably, the position coordinates on said four summits according to said view field, and the position coordinates of proofreading and correct four summits of rectangle, it is concrete according to following formula to calculate the geometric correction parameter:

$\left[\begin{array}{c}{x_i}^{\′}\\ {y_i}^{\′}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{U\; v}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]}$ (formula 1)

Wherein, i is the integer between [1,4], (x ₁, y ₁), (x ₂, y ₂), (x ₃, y ₃), (x ₄, y ₄) be the position coordinates on four summits of said view field; (x ₁', y ₁'), (x ₂', y ₂'), (x ₃', y ₃'), (x ₄' y ₄') be the position coordinates on four summits of said correction rectangle; A, b, c, d, e, f, u, v are the geometric correction parameter that calculates.

Preferably, the said geometric correction parameter of said use is made operation transform to the original image that needs projection, and the image after obtaining proofreading and correct comprises:

If if (x y) is a locations of pixels coordinate in the original image, then based on following formula:

$\left[\begin{array}{c}{x}^{\′}\\ y^{\′}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{U\; v}\right]\left[\begin{array}{c}x\\ y\end{array}\right]}$ (formula 2)

Determine the position coordinates (x ', y ') of respective pixel in the image after the correction.

Wherein, the position coordinates on four of said correction rectangle summits is for confirm in advance; Perhaps, the position coordinates on four of said correction rectangle summits is to confirm according to the position coordinates on four summits of view field in the said photographic images.

The position coordinates on four summits of said correction rectangle is to confirm to comprise according to the position coordinates on four summits of view field in the said photographic images: for four quadrangles that the summit constituted by view field in the said photographic images, confirm that the position coordinates on four summits of said correction rectangle is positioned within the said quadrangle; Perhaps; For said four quadrangles that the summit constituted by view field in the said photographic images; The position coordinates of confirming four summits of said correction rectangle is positioned within the said quadrangle, and the ratio of width to height of said correction rectangle is identical with the ratio of width to height of said original image.

Further; By photographing module the view field that projecting apparatus projects on display screen is being taken; Obtain also comprising after the photographic images: authentication module carries out geometric distortion to view field in the said photographic images to be judged, and the geometric distortion judged result is sent to said correction module; And; After the view field of said correction module in determining said photographic images; Determine corresponding geometric correction parameter; Be specially: said correction module is determined the view field in the said photographic images, and is determined corresponding geometric correction parameter after definite said geometric distortion judged result is distortion.

Further; By photographing module the view field that projecting apparatus projects on display screen is being taken; Obtain after the photographic images; Also comprise: a, correction module determine primary colours to be adjusted according to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to said projection module; Said brightness adjusted value is predetermined; B, said projection module are according to the brightness of the corresponding primary colours of the said brightness adjusted value adjustment light source of waiting to adjust primary colours; C, correction module continue to obtain the photographic images of said photographing module current shooting; And the relative distance between the chromaticity coordinates of the background colour of the view field in determining the current photographic images that obtains of said photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate system finishes correction this time during less than set point; Otherwise, repeating step a, b, c.

Further; By photographing module the view field that projecting apparatus projects on display screen is being taken; Obtain also comprising after the photographic images: authentication module carries out cross-color to view field in the said photographic images to be judged, and the cross-color judged result is sent to said correction module; And; Correction module is according to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system; Confirm that primary colours to be adjusted are specially: said correction module is after definite said cross-color judged result is distortion; According to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system, confirm primary colours to be adjusted.

Wherein, Said authentication module carries out cross-color to view field in the said photographic images and judges and to comprise: said authentication module confirms that then said cross-color judged result is distortion if chromaticity coordinates and the distance between the chromaticity coordinates of object color component in hue coordinate system of the background colour of confirming the view field in the current photographic images that obtains of said photographing module in hue coordinate system surpasses the setpoint distance value; Otherwise, confirm that said cross-color judged result is undistorted.

Said correction module is according to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system; Confirm that primary colours to be adjusted comprise: the chromaticity coordinates of establishing three primary light source is respectively R, G, B point in said hue coordinate is; The chromaticity coordinates of said object color component is the W point in hue coordinate system, and the chromaticity coordinates of the background colour of the view field in the current photographic images that obtains of said photographing module is the T point in hue coordinate system; Straight line RW, GW, BW cross straight line BG, BR, GR respectively in a P, N, M, and triangle RGB is divided into GWM, BWN, GWP, RWN, RWM, the little triangle of BWP; If the T point is positioned at little triangle GWM or BWN, confirm that then primary colours to be adjusted are the R primary colours, and the brightness adjusted value of R primary colours be on the occasion of; If the T point is positioned at little triangle GWP or RWN, confirm that then primary colours to be adjusted are the B primary colours, and the brightness adjusted value of B primary colours be on the occasion of; If the T point is positioned at little triangle RWM or BWP, confirm that then primary colours to be adjusted are the G primary colours, and the brightness adjusted value of G primary colours be on the occasion of; If T point overlaps with the extended line of BW line segment perhaps less than setting threshold, confirm that then primary colours to be adjusted are the B primary colours, and the brightness adjusted value of B primary colours be on the occasion of; If T point overlaps with the extended line of RW line segment perhaps less than setting threshold, confirm that then primary colours to be adjusted are the R primary colours, and the brightness adjusted value of R primary colours be on the occasion of; If T point overlaps with the extended line of GW line segment perhaps less than setting threshold, confirm that then primary colours to be adjusted are the G primary colours, and the brightness adjusted value of G primary colours be on the occasion of.

According to another aspect of the present invention, a projecting apparatus is provided also, has comprised: photographing module, be used for the view field that projecting apparatus projects on display screen is taken, obtain photographic images; Correction module is used for the view field according to said photographic images, determines corresponding geometric correction parameter; And use said geometric correction parameter that the original image that needs projection is made operation transform, the image after obtaining proofreading and correct; Projection module is used for the image projection after the said correction to display screen.

Preferably; Said correction module is used for the view field according to said photographic images; Determining corresponding geometric correction parameter comprises: according to the position coordinates on four summits of said view field, and the position coordinates of proofreading and correct four summits of rectangle, calculate the geometric correction parameter; Wherein, the position coordinates on four of said correction rectangle summits is predetermined; Perhaps, the position coordinates on four of said correction rectangle summits is to confirm according to the position coordinates on four summits of view field in the said photographic images.

Said projecting apparatus further comprises: authentication module is used for that said photographic images view field is carried out geometric distortion and judges, and the geometric distortion judged result is sent to said correction module; And said correction module specifically is used for after definite said geometric distortion judged result is distortion, determines the view field in the said photographic images, and determining corresponding geometric correction parameter; And use said geometric correction parameter that the original image that needs projection is made operation transform, the image after obtaining proofreading and correct.

Further, said authentication module is used for that also said photographic images view field is carried out cross-color to be judged, and the cross-color judged result is sent to said correction module.

Said correction module also is used for after definite said cross-color judged result is distortion; According to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system, confirm primary colours to be adjusted; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to said projection module; Said brightness adjusted value is predetermined; And said projection module also is used for the brightness according to the corresponding primary colours of the said brightness adjusted value adjustment light source of waiting to adjust primary colours; And; Said correction module also is used at the photographic images that continues to obtain said photographing module current shooting; And the relative distance between the chromaticity coordinates of the background colour of the view field in determining the current photographic images that obtains of said photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate is is during less than set point; Continuation is determined primary colours to be adjusted according to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to said projection module.

Wherein, said authentication module comprises: the geometric distortion judging unit is used for that said photographic images view field is carried out geometric distortion and judges, and the geometric distortion judged result is sent to said correction module; The cross-color judging unit is used for that said photographic images view field is carried out cross-color and judges, and the cross-color judged result is sent to said correction module.

Said correction module comprises: the geometric correction processing unit is used to receive the geometric distortion judged result that said geometric distortion judging unit sends; If said geometric distortion judged result is distortion, then determines the view field in the said photographic images, and determine corresponding geometric correction parameter; Use said geometric correction parameter that the original image that needs projection is made operation transform, the image after obtaining proofreading and correct; The color correction process unit is used to receive the cross-color judged result that said cross-color judging unit sends; If said cross-color judged result is distortion; Then:, confirm primary colours to be adjusted according to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to said projection module; And; After of the brightness of said projection module according to the corresponding primary colours of the said brightness adjusted value adjustment light source of waiting to adjust primary colours; Continue to obtain the photographic images of said photographing module current shooting; And the relative distance between the chromaticity coordinates of the background colour of the view field in determining the current photographic images that obtains of said photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate is is during less than set point; Continuation is determined primary colours to be adjusted according to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to said projection module.

Said projection module comprises: the image-driven unit, and the image after the correction that is used for sending according to said geometric correction processing unit carries out projection; Light source driving units is used for adjusting according to waiting of sending of said color correction process unit the brightness of corresponding primary colours of the brightness adjusted value adjustment light source of primary colours.

The projecting apparatus of the embodiment of the invention is owing to analyze the view field in the photographic images; Carrying out geometric correction handles or color correction process; Thereby needn't have the predetermined image of certain characteristic through projection, carry out correct operation, thereby simplify the process of correcting orthographic projection image.

Because the projecting apparatus of the embodiment of the invention is in the process of carrying out geometric correction or color correction; The predetermined image that needn't projection has certain characteristic; Therefore, above-mentioned S501-S507 step, perhaps the S801-S807 step not only can be carried out trimming process at the baseline of projection; Also can be in normal projection process; Obtain photographic images in real time through photographing module, authentication module can carry out geometric distortion to photographic images in real time and judge that perhaps cross-color is judged, correction module can carry out geometric correction in real time to be handled or color correction process.Therefore, the projecting apparatus of the embodiment of the invention and projected picture correcting method thereof can carry out geometric correction or color correction more conveniently.

Because the projecting apparatus of the embodiment of the invention can be realized color correction, make the application scenario of projecting apparatus be not limited to the occasion of display screen for white.For the display screen of other color, like ecru etc., can pass through color adjustment, and make the image effect that projects identical with effect on projecting to white display screen, it is more convenient to make that projecting apparatus uses.

Description of drawings

Fig. 1 is the internal frame diagram of the projecting apparatus with automatic correcting orthographic projection image function of prior art;

Fig. 2 is the not calibrated sketch map that the projected image of geometric distortion occurs of the embodiment of the invention;

Fig. 3 is the sketch map with the image of original image after obtaining behind the transform operation proofreading and correct of the embodiment of the invention;

Fig. 4,7 is the projecting apparatus block diagram of the embodiment of the invention;

Fig. 5 is the projected image geometric correction method flow chart of the embodiment of the invention;

Fig. 6 is the sketch map on definite correction rectangle summit of the embodiment of the invention;

Fig. 8 is the projected image geometric correction and the color calibration method flow chart of the embodiment of the invention;

Fig. 9 a is the sketch map of chromaticity coordinates of chromaticity coordinates and the object color component of view field's background colour in the hue coordinate system of the embodiment of the invention;

Fig. 9 b is the detailed color calibration method flow chart of the embodiment of the invention;

Figure 10 is the sketch map that the adjustment T point of the embodiment of the invention overlaps with the W point;

Figure 11 is a kind of projecting apparatus internal structure sketch map of the embodiment of the invention.

Embodiment

For making the object of the invention, technical scheme and advantage clearer, below with reference to accompanying drawing and enumerate preferred embodiment, to further explain of the present invention.Yet, need to prove that many details of listing in the specification only are in order to make the reader to one or more aspects of the present invention a thorough understanding arranged, even if there are not these specific details also can realize these aspects of the present invention.

Terms such as " module " that the application uses, " system " are intended to comprise the entity relevant with computer, such as but not limited to hardware, firmware, combination thereof, software or executory software.For example, module can be, but be not limited in: the thread of the process of moving on the processor, processor, object, executable program, execution, program and/or computer.For instance, the application program of moving on the computing equipment can be a module with this computing equipment.One or more modules can be positioned at an executory process and/or thread, and module also can be on the computer and/or be distributed between two or more the computers.In addition, can carry out these modules through the multiple computer-readable medium of having stored plurality of data structures.These modules can communicate through signal utilization this locality and/or remote process.

Inventor of the present invention finds that if the optical axis that projector projects goes out becomes an angle of inclination with screen surface, the view field that on display screen, demonstrates so can not be the rectangle of rule, but geometric distortion has promptly appearred in a kind of quadrangle of distortion.If projecting apparatus need be with certain width of cloth image projection to display screen, for example, need be to display screen with certain page of lantern slide projection in the PPT document; Perhaps, need certain photos be projected on the display screen; So, because the optical axis that projects becomes an angle of inclination with screen surface, the projected image that is shown in the view field on display screen also geometric distortion can correspondingly occur.Fig. 2 shows a kind of not calibrated and the projected image of geometric distortion occurs.

Based on this analysis, thinking of the present invention is: need the original image of projection to proofread and correct to projecting apparatus in advance, and for example shown in Figure 3, behind certain transform operation of original image process with a width of cloth rectangle, the image after obtaining proofreading and correct.Image after the correction has not been the rectangle of rule, but the irregular quadrangle after having taken place to change for how much.Image after projecting apparatus is proofreaied and correct this; After promptly this irregular quadrilateral image carries out projection; The distortion of the image after this correction just in time offsets with the deformation factor that inclined light shaft produces, thereby the projected image that in the view field of display screen, shows is the rectangular image of rule.That is to say that the image after the correction is through after the projection, the projected image that in view field, shows has not had geometric distortion with respect to original image.And can draw with reference to the distortion degree of view field the parameter that original image carries out transform operation.That is to say, take the view field of projecting apparatus on display screen, analyze the distortion situation of view field in the photographic images, just can calculate the parameter (or claiming the geometric correction parameter) of anti-distortion through camera.Utilize anti-distortion parameter (or claiming the geometric correction parameter) that original image is carried out conversion, the image after obtaining proofreading and correct in the time of just can making the image projection of projecting apparatus after will proofreading and correct to display screen, no longer includes geometric distortion.

Specify the technical scheme of the embodiment of the invention below in conjunction with accompanying drawing.As shown in Figure 4, a kind of projecting apparatus that the embodiment of the invention provides comprises: photographing module 401, projection module 402, correction module 403.

Projection module 402 projects light on the display screen, on display screen, demonstrates the higher view field of brightness, i.e. the brightness of view field will be higher than the brightness of the non-view field that does not have projection ray's irradiation.If projection module 402 also projects image onto on the display screen, will in view field, demonstrate corresponding projected image so.If the optical axis that projection module 402 projects becomes an angle of inclination with screen surface, the view field of the high brightness that demonstrates on the display screen so will can not be the rectangle of rule, but geometric distortion has promptly appearred in a kind of quadrangle of distortion.Suppose that again projection module 402 does not project to a width of cloth in the view field through the original image of treatment for correcting, projected image also corresponding geometric distortion can occur so.

Photographing module 401 is fixedly set on the projecting apparatus, and preferably, the adjacent projection module 402 that is arranged at for example is arranged on the top of projection module 402, is used for the view field that projecting apparatus projects on display screen is taken, and obtains photographic images.In actual applications, photographing module 401 can be taken the view field that projects on the display screen continuously.

Correction module 403 is used for view field according to photographic images and determines corresponding geometric correction parameter and carry out geometric correction and handle.Particularly, correction module 403 is determined the position coordinates on four summits of view field in the photographic images; And according to the position coordinates on four summits of the view field that confirms, calculate the geometric correction parameter after, use the geometric correction parameter original image that needs projection to be made operation transform, the image after obtaining proofreading and correct.Image after the correction that correction module 403 will calculate sends to projection module 402.

Image after projection module 402 will be proofreaied and correct carries out projection.After the distortion factor that distortion in images factor after the correction and inclined light shaft produce offsets, on display screen, demonstrate the projected image that does not have geometric distortion with respect to original image, thereby realized the correction of projected image.

Introduce the method that the projecting apparatus of the embodiment of the invention carries out geometric correction to projected image below in detail, flow process is as shown in Figure 5, and at step S501, projection module 402 projects light on the display screen, on display screen, demonstrates the higher view field of brightness.Certainly, projection module 402 in the Display projector zone, both can carry out projection to image on display screen, also can not carry out image projection.If carry out image projection, in view field, will demonstrate the respective projection image.Next, at step S502, the view field that the projection module 402 of 401 pairs of projecting apparatus of photographing module projects on display screen takes, and obtains photographic images.Then, correction module 403 is determined the view field (step S503) in the photographic images.Particularly, because the image of taking is preserved with the mode of pixel-matrix usually, each pixel has all comprised this locations of pixels information, monochrome information.Positional information i.e. the position coordinates of this pixel in image, and monochrome information can be the brightness value of this pixel.In the captured image of photographing module 401, both comprise the higher view field of brightness on the display screen, also comprised the subregion that does not have projection on the display screen.Therefore, in photographic images, the brightness value of view field is greater than the zone that does not have projection.So, the brightness value of the pixel in the analysis photographic images can be determined the border of view field.How to confirm the technology that the border of view field is well known to those skilled in the art, repeat no more here according to the brightness value of the pixel in the photographic images.At step S504, correction module 403 is confirmed corresponding geometric correction parameter according to the view field of said photographic images.Particularly, correction module 403 can be recognized the degree of the geometric distortion that the projecting apparatus optical axis causes because of inclination, and then determine anti-distortion parameter, i.e. geometric correction parameter in having confirmed photographic images after the view field.For example, correction module 403 can be got the position coordinates of four points in the view field, recognizes the degree of the geometric distortion that the projecting apparatus optical axis causes because of inclination according to the position coordinates of these four points, and then determines anti-distortion parameter.The transformation theory of above-mentioned elimination distortion can solve through the mathematical computations mode.A kind of preferable scheme is; Because view field is generally quadrangle; Therefore the degree of the geometric distortion that the projecting apparatus optical axis causes because of inclination be can recognize according to the position coordinates on four summits of view field in the photographic images, and then anti-distortion parameter, i.e. geometric correction parameter determined.Suppose that be in the xy coordinate system of forward at x axle and y axle, four of view field summits begin from the upper left corner in the said photographic images, are followed successively by A, B, C, D point clockwise, and the position coordinates on A, B, C, four summits of D is respectively (x ₁, y ₁), (x ₂, y ₂), (x ₃, y ₃), (x ₄, y ₄).

In fact, can be according to the position coordinates on four summits of view field, and certain proofreaies and correct the position coordinates on four summits of rectangle, confirms the geometric correction parameter.Hypothesis is in the xy coordinate system of forward at x axle and y axle here, and four summits of this correction rectangle begin from the upper left corner, are followed successively by A ', B ', C ', D ' point clockwise, and A ', B ', C ', D ' position coordinates is respectively (x ₁', y ₁'), (x ₂', y ₂'), (x ₃', y ₃'), (x ₄', y ₄').

The position coordinates of proofreading and correct four summits of rectangle can be predetermined.For example, setting and proofreading and correct rectangle is a rectangular area of setting size placed in the middle in the photographic images, thus, proofreaies and correct the position coordinates on four summits of rectangle and also sets.

Perhaps, the position coordinates of proofreading and correct four summits of rectangle can be to confirm according to the position coordinates on four summits of view field in the said photographic images.Preferably, proofreading and correct rectangle can be the rectangle that is positioned at view field, promptly for four quadrangles that the summit constituted by view field in the said photographic images, confirms that the position coordinates on four summits of said correction rectangle is positioned within the said quadrangle.Further; For the image after guaranteeing to proofread and correct consistent with the ratio of width to height of original image; That is to say; For fear of the situation that image is crushed or stretches occurring,, can also make the ratio of width to height of this correction rectangle identical with the ratio of width to height of original image except letting the position coordinates on four summits of said correction rectangle be arranged within four quadrangles that the summit constituted of said photographic images view field.How to determine one and proofread and correct rectangle; Make this correction rectangle be arranged within four quadrangles that the summit constituted of photographic images view field; And the ratio of width to height that should proofread and correct rectangle is identical with the ratio of width to height of original image, and the technology that is well known to those skilled in the art repeats no more here.

As shown in Figure 6, following equality 1-4 has provided a kind of method of position coordinates of four summits determining the correction rectangle that is positioned at view field:

x ₁'=x ₄'=max (x ₁, x ₄); (equality 1)

x ₂'=x ₃'=min (x ₂, x ₃); (equality 2)

y ₁'=y ₂'=min (y ₁, y ₂); (equality 3)

y ₃'=y ₄'=max (y ₃, y ₄); (equality 4)

Above-mentioned max is expressed as the value in the bracket is got maximum, and min is expressed as the value in the bracket is got minimum value.

Correction module 403 is according to the position coordinates on four summits of view field in the said photographic images, and the position coordinates of proofreading and correct four summits of rectangle, calculates the geometric correction parameter according to following formula 1:

$\left[\begin{array}{c}{x_i}^{\′}\\ {y_i}^{\′}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{U\; v}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]}$ (formula 1)

In the above-mentioned formula 1, i is the integer between [1,4]; A, b, c, d, e, f, u, v are the geometric correction parameter that calculates.

Next, at step S505, correction module 403 uses the geometric correction parameter original image that needs projection to be made operation transform, the image after obtaining proofreading and correct.Suppose, certain the locations of pixels coordinate in the original image be (x y), then can calculate the position coordinates (x ', y ') of respective pixel in the image after the correction according to following formula 2:

$\left[\begin{array}{c}{x}^{\′}\\ y^{\′}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{U\; v}\right]\left[\begin{array}{c}x\\ y\end{array}\right]}$ (formula 2)

Obviously, can the arbitrary locations of pixels coordinate in the original image be updated to the x in the above-mentioned formula 2, in the y value, thus the position coordinate value x ' of respective pixel in the image after obtaining proofreading and correct, y '.After all pixels in the original image are carried out operation transform according to above-mentioned formula 2, the image after can obtaining proofreading and correct.

Further,, so, can after original image is made operation transform, carry out interpolation arithmetic in the resulting image, obtain the image after the final correction owing to after original image makes operation transform, can lose the characteristic of some pixels.Through interpolation arithmetic, can replenish the pixel that lacks because of image zoom, eliminate possible mosaic phenomenon, the content of display frame is seamlessly transitted, do not influence viewing effect.

At step S506, the image after correction module 403 will be proofreaied and correct sends to projection module 402.At step S507, the image projection after projection module 402 will be proofreaied and correct is to display screen.Through the image after the resulting correction behind the operation transform; Produced certain geometric distortion with respect to original image; After the distortion factor that distortion in images factor after the correction and inclined light shaft produce offsets; On display screen, demonstrate the projected image that does not have geometric distortion with respect to original image, thereby realized the geometric correction of projected image.

More excellent ground can also comprise authentication module 404 in the projecting apparatus of the embodiment of the invention, and is as shown in Figure 7.

Authentication module 404 is arranged between photographing module 401 and the correction module 403, is used for photographic images that photographing module 401 is obtained, carries out geometric distortion and judges, and the geometric distortion judged result is sent to correction module 403.

Preferably, whether correction module 403 carries out the geometric correction processing according to the geometric distortion judged result decision that authentication module 404 sends:

If the geometric distortion judged result is distortion, then correction module 403 is made operation transform according to the method for above-mentioned steps S503-S505 to original image, the image after obtaining proofreading and correct, and the image after will proofreading and correct sends to projection module 402 and carries out Projection Display.If the geometric distortion judged result is undistorted, then correction module 403 needn't carry out the geometric correction processing, directly original image is sent to projection module 402 and carries out Projection Display.

In projection process, except meeting generation geometric distortion, deviation also can take place in the color of image, and cross-color occurs.Such as, projected image integral body is orange partially etc., is a kind of cross-color.

Further, the projecting apparatus of the embodiment of the invention can also carry out color correction process.Particularly, authentication module 404 can also carry out photographic images that photographing module 401 is obtained, carries out cross-color and judges, and the cross-color judged result is sent to correction module 403.

The cross-color judged result that correction module 403 Receipt Validation modules 404 are sent, and according to the cross-color judged result whether decision carries out color correction process:

If the cross-color judged result is distortion, then correction module 403 is confirmed primary colours to be adjusted according to the background colour of the view field in the current photographic images that obtains of photographing module, and will wait that the brightness adjusted value of adjusting primary colours sends to projection module 402; Projection module 402 is adjusted the brightness of the corresponding primary colours of light source according to the brightness adjusted value of waiting to adjust primary colours that receives afterwards; Photographing module 401 continues the view field that the projection module 402 to projecting apparatus projects on display screen takes, and obtains photographic images.Correction module 403 continues to obtain the photographic images of photographing module 401 current shooting; And the relative distance between the chromaticity coordinates of the background colour of the view field in determining the photographing module 401 current photographic images that obtain in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate is finishes this color correction during less than set point; Otherwise; Continuation is according to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system; Confirm primary colours to be adjusted, and this is waited that the brightness adjusted value of adjusting primary colours continues to send to projection module 402.Concrete color correction process method will be introduced follow-up.If the cross-color judged result is undistorted, then correction module 403 needn't carry out color correction process, does not promptly send the brightness adjusted value of waiting to adjust primary colours to projection module 402.The luminance primary of 402 pairs of projection light sources of projection module does not change.

The geometric distortion of the projecting apparatus of the embodiment of the invention is judged, trimming process, and cross-color is judged, the flow process of trimming process, and is as shown in Figure 8.At step S801, projection module 402 projects light on the display screen, on display screen, demonstrates the higher view field of brightness.Next, at step S802, the view field that the projection module 402 of 401 pairs of projecting apparatus of photographing module projects on display screen takes, and obtains photographic images.At step S803, the photographic images that 404 pairs of photographing modules 401 of authentication module obtain carries out geometric distortion and judges, and the geometric distortion judged result is sent to correction module 403.

Authentication module 404 can be according to the relative edge's of the view field in the photographic images length of side ratio, and the angle of adjacent edge carries out geometric distortion and judges.Particularly, in the quadrangle that view field constituted:

If the included angle X of adjacent edge exceeds the scope of setting, then to judge geometric distortion has taken place, the scope of for example setting is 85 °～95 °, then judges geometric distortion has taken place if λ exceeds this scope.Obviously, there are many other methods to judge whether λ exceeds the scope of setting.In an embodiment of the present invention, judge as follows: as setting the σ value, if λ satisfies like lower inequality 1:

$\mathrm{\&sigma;}<\frac{\mathrm{\&lambda;}}{90}<\frac{1}{\mathrm{\&sigma;}}$ (inequality 1)

Judge that then λ does not exceed the scope of setting; Otherwise, judge that λ exceeds the scope of setting.The value of σ can confirm according to actual conditions, as requires effective desirablely 0.95, requires effect not high by desirable 0.8.

If the included angle X of adjacent edge does not exceed the angular range of setting, whether relative edge's the length of side ratio of then proceeding to judge view field is in setting range.The quadrangle of view field has two pairs of opposite side.Respectively to opposite side not being judged that length of side ratio is whether in setting range.If there is the length of side ratio of a pair of opposite side to exceed setting range, then judges geometric distortion takes place.For example, be the view field that A, B, C, D are ordered for above-mentioned summit, AB limit and DC limit are opposite side, AD limit and BC limit are opposite side, l _AB, l _DC, l _AD, l _BCBe respectively the length of side on AB limit, DC limit, AD limit, BC limit.If l _AB, l _DC, l _AD, l _BCOne of do not satisfy in following inequality 2 and the inequality 3, then judge geometric distortion takes place:

$\mathrm{\&epsiv;}<\frac{l_{\mathrm{AB}}}{l_{\mathrm{DC}}}<\frac{1}{\mathrm{\&epsiv;}}$ (inequality 2)

$\mathrm{\&epsiv;}<\frac{l_{\mathrm{AD}}}{l_{\mathrm{BC}}}<\frac{1}{\mathrm{\&epsiv;}}$ (inequality 3)

Those skilled in the art can set the ε value according to actual conditions.For example, as to require the effective preferably ε of setting be 0.95, is 0.8 if require the not high ε of setting of effect; In general, the setting range of ε can be (0.6≤ε≤1).

At step S804, authentication module 404 can also carry out the current photographic images to photographing module 401 shootings, carries out cross-color and judges, and the cross-color judged result is sent to correction module 403.

Particularly; Authentication module 404 can be according to photographic images; Confirm the chromaticity coordinates of background colour in hue coordinate system of the view field in the photographic images, carry out the cross-color judgement according to the chromaticity coordinates of background colour and the distance between the chromaticity coordinates of object color component in hue coordinate system.The chromaticity coordinates of supposing view field's background colour is the T point in the hue coordinate system, and the chromaticity coordinates of object color component is the W point (shown in Fig. 9 a) in the hue coordinate system.The chromaticity coordinates of object color component is predefined.Authentication module 404 calculates the T point to the distance between the W point, if distance surpasses the setpoint distance value, confirms that then the cross-color judged result is distortion; Otherwise, confirm that said cross-color judged result is undistorted.For example, calculate T point and W point in hue coordinate is apart from δ, like satisfied 0≤δ≤γ, can think then to meet the requirements that the γ span is redefined for 0≤γ≤0.03.

A kind of concrete grammar of chromaticity coordinates of confirming the background colour of the view field in the photographic images can be: behind four summits of the view field in determining photographic images, obtain the chromaticity coordinates on these four summits.With the mean value of the chromaticity coordinates on these four summits chromaticity coordinates as the background colour of the view field in the photographic images.For example, the chromaticity coordinates of supposing four summits of the view field in the photographic images is respectively: (x _C1, y _C1), (x _C2, y _C2), (x _C3, y _C3), (x _C4, y _C4).Chromaticity coordinates (the x of the background colour of the view field in the photographic images then _c, y _c), confirm according to following equality 5,6:

$x_c=\frac{x_{c1}+x_{c2}+x_{c3}+x_{c4}}{4}$ (equality 5)

$y_c=\frac{y_{c1}+y_{c2}+y_{c3}+y_{c4}}{4}$

(equality 6)

To those skilled in the art can be not only confirm the chromaticity coordinates of the background colour of view field also can adopt the chromaticity coordinates of other point in the view field to confirm with the chromaticity coordinates on four summits of view field.

Obviously, step S803 and S804 can carry out simultaneously, also can carry out S803 earlier, perhaps carry out S804 earlier.

At step S805, if the geometric distortion judged result is distortion, then 403 pairs of original images of correction module carry out geometric correction and handle, the image after obtaining proofreading and correct, and the image after will proofreading and correct sends to projection module 402 and carries out Projection Display.Be that correction module 403 is determined corresponding geometric correction parameter according to the view field in the said photographic images; Using the geometric correction parameter that original image is carried out geometric correction handles; Behind the image after obtaining proofreading and correct, the image after proofreading and correct is sent to projection module 402 carry out Projection Display.The method that correction module 403 geometric corrections are handled has been detailed in above-mentioned steps S503-S505, has repeated no more here.

Next at step S806, if the geometric distortion judged result is undistorted, then correction module 403 needn't carry out the geometric correction processing, directly original image is sent to projection module 402 and carries out Projection Display.If the cross-color judged result is distortion, then color correction process (step S807) is carried out in correction module 403, photographing module 401 and projection module 402 cooperations.

Correction module 403, photographing module 401 and projection module 402 cooperate the detailed process that carries out color correction process shown in Fig. 9 b.At step S901, the view field that 401 pairs of projecting apparatus of photographing module project on display screen takes, and obtains photographic images.Correction module 403 is confirmed primary colours to be adjusted (step S902) according to the background colour of the view field in the current photographic images that obtains of photographing module.Particularly, correction module 403 is confirmed primary colours to be adjusted according to the background colour of the view field in the photographing module 401 current photographic images that obtain chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system.

Particularly; Correction module 403 is according to photographic images; Confirm the chromaticity coordinates of background colour in hue coordinate system of the view field in the photographic images,, determine primary colours to be adjusted according to the chromaticity coordinates and the chromaticity coordinates of object color component in hue coordinate system of background colour; After making that adjusted this waits to adjust primary colours, the background colour of the view field in the photographic images of taking once more to object color component near; Just, make that adjusted this waits to adjust primary colours after, the chromaticity coordinates of the background colour of the view field in the photographic images of taking once more to the chromaticity coordinates of object color component near.

Concrete grammar can be shown in figure 10; The chromaticity coordinates of three primary light source is respectively R, G, B point in hue coordinate system; The chromaticity coordinates of object color component is the W point in hue coordinate system, and the chromaticity coordinates of the view field's background colour in the photographic images of current shooting is the T point in hue coordinate system.R, the connection of W point and prolongation are obtained straight line RW, and G, W point connect and prolongation obtains straight line GW, and B, W point connect and prolongation obtains straight line BW.

At first confirm and the nearest straight line of T point among straight line RW, GW, the BW, confirm to wait to adjust primary colours and this waits to adjust the brightness adjusted value of primary colours according to this nearest straight line.Specifically comprise as follows: judge the brightness of adjustment T which primary colours of ordering, the T point is moved to this nearest straight line, then these primary colours are primary colours to be adjusted.For example, it is nearest to determine T point and straight line BW, in Figure 10, because T point and G point are positioned at the same side of straight line BW, then can make the T point move to straight line BW through heightening the R luminance primary that T orders, and thus, judging these primary colours to be adjusted is the R primary colours; Certainly, also can promptly reduce B and G luminance primary and make the T point move to straight line BW through reducing the brightness of other dichromatism that T orders, thus, judging these primary colours to be adjusted is B and G primary colours.

, then judge this and wait that the method for adjusting primary colours is less than setting threshold or situation about coinciding for the distance between T point and the straight line: judge the brightness of which primary colours that adjustment T order, can make the T point mobile to the W point, then these primary colours are primary colours to be adjusted.For example, the T point overlaps with straight line BW, can be through heightening the B luminance primary that T orders so that the T point move to W, and thus, judging these primary colours to be adjusted is the B primary colours; Certainly, also can promptly reduce R and G luminance primary and make the T point move to W through reducing the brightness of other dichromatism that T orders, judging primary colours to be adjusted thus is R and G primary colours.Those skilled in the art can be provided with setting threshold according to actual conditions.

Another kind of judge wait that the preferred approach of adjusting primary colours is: shown in figure 10, straight line RW comprises line segment and the extended line of RW line segment between the RW; Straight line BW comprises line segment and the extended line of BW line segment between the BW; Straight line GW comprises line segment and the extended line of GW line segment between the GW.At first, confirm and the nearest extended line of T point.Judge and wait that the method for adjusting primary colours is: judge the brightness of adjustment T which primary colours of ordering, the T point is moved to this nearest extended line, then these primary colours are primary colours to be adjusted.Determination methods and above-mentioned similar repeats no more here.

For the distance between T point and this nearest extended line less than setting threshold or situation about coinciding; Then judge this and wait that the method for adjusting primary colours is: judge the brightness of adjustment T which primary colours of ordering; The T point is moved to the W point, and then these primary colours are primary colours to be adjusted.For example, the T point overlaps with the extended line of BW line segment, can be through heightening the B luminance primary that T orders so that the T point move to W, and thus, judging these primary colours to be adjusted is the B primary colours.

Through this method, can adjust light source through increasing luminance primary, rather than reduce luminance primary and adjust light source.

At step S903, the brightness adjusted value of adjusting primary colours of waiting that correction module 403 will be confirmed sends to projection module 402.Correction module 403 can wait that the brightness adjusted value of adjusting primary colours sends to projection module 402 with this after having confirmed to wait to adjust primary colours.For example, in the above-mentioned example, can be through heightening the R luminance primary that T orders so that the T point moves to straight line BW, judging these primary colours to be adjusted thus is the R primary colours owing to be to heighten the R luminance primary, therefore, the brightness adjusted value can for one predetermined on the occasion of.This brightness adjusted value is a predetermined proper step value, confirms primary colours to be adjusted again and again through follow-up, and sends the brightness adjusted values to projection module 402, makes that T point is final perhaps to overlap with the W point is approaching.

For another example, in the above-mentioned example, through reducing the brightness of other dichromatism that T orders; Promptly reducing B and G luminance primary makes the T point move to straight line BW; Thus, judging these primary colours to be adjusted is B and G primary colours, owing to be to reduce B and G luminance primary; Therefore, the brightness adjusted value of B and G can be a predetermined negative value.

At step S904, projection module 402 is adjusted the brightness of the corresponding primary colours of light source according to the brightness adjusted value of waiting to adjust primary colours that receives.Particularly, projection module 402 receive wait to adjust the brightness adjusted value of primary colours after, for example, the brightness adjusted value is the brightness adjusted value of R primary colours, and this brightness adjusted value is being for just, then certain brightness of the R primary colours of projection module 402 corresponding raising light sources.For another example, the brightness adjusted value is the brightness adjusted value of B and G primary colours, and this brightness adjusted value is for bearing then certain brightness of the B of projection module 402 corresponding reduction light sources and G primary colours.Projection module 402 improves or reduces the degree of luminance primary and confirms according to the absolute value of brightness adjusted value.Adjusted the luminance primary of light source at projection module 402 after, the background colour that projects to the image on the display screen will change.

At step S905; Correction module 403 continues to obtain the photographic images of photographing module 401 current shooting, and judges that whether relative distance between the chromaticity coordinates of chromaticity coordinates and object color component of background colour of the view field in the current photographic images that obtains is less than set point; If less than, then finish this color correction, execution in step S906; Otherwise, repeating step S902-S905.

Adjusted the luminance primary of light source at projection module 402 after, respective change also can take place in the background colour of the view field in the photographic images that photographing module 401 obtains.Correction module 403 continues the chromaticity coordinates of the background colour of the view field that has taken place to change and the chromaticity coordinates of object color component are compared.If both relatively near perhaps overlapping, have so just reached the purpose of color correction, just can finish this color correction process; Otherwise, also need proceed color correction.Those skilled in the art can confirm set point according to actual conditions, if having relatively high expectations, set point can be provided with less; If requirement is lower, set point can be provided with bigger.Certainly, also can set point be made as 0, i.e. the situation that expression overlaps fully.It is identical with above-mentioned setpoint distance value that this setting value can be provided with, or more less than above-mentioned setpoint distance value.

Through repeating step S902-S905, make that the chromaticity coordinates W point of chromaticity coordinates T point and object color component of background colour of view field is more and more approaching, until reaching requirement, thereby reach the purpose of color correction.

Usually, the chromaticity coordinates W point of object color component is positioned at the triangle of R, G, B point formation.Straight line RW, GW, BW cross straight line BG, BR, GR respectively in a P, N, M, and triangle RGB is divided into a plurality of little triangles.

List the T point in the form as shown in table 1 and laid respectively under the different little leg-of-mutton situation, confirmed to wait to adjust the method for primary colours.For example, be positioned at the situation of little triangle RWM, then confirm to increase earlier the G luminance primary, confirm that promptly primary colours to be adjusted are the G primary colours for the T point, and the brightness adjusted value of G primary colours be on the occasion of; The brightness adjusted value of waiting to adjust primary colours G primary colours that the process projection module repeatedly sends according to correction module; Transfer the G primary colours of projection light source more bright gradually, make the background colour coordinate of the view field in the photographic images of taking module current shooting more and more near BW straight line (or extended line of BW line segment).The background colour coordinate of the view field in the photographic images of taking module current shooting; Be that the T point overlaps with BW straight line (or extended line of BW line segment) perhaps less than setting threshold; Then confirm to increase the B luminance primary, confirm that promptly primary colours to be adjusted are the B primary colours, and the brightness adjusted value of B primary colours be on the occasion of.

Table 1

Triangle of living in	The first step increases luminance primary	Second step increased luminance primary
			GWM	R	B
GWP	B	R
			RWM	G	B
RWN	B	G
			BWP	G	R
BWN	R	G

Confirming shown in the above-mentioned table 1 waits that the mode of adjusting primary colours specifically describes as follows:

If the T point is positioned at little triangle GWM or BWN, confirm that then primary colours to be adjusted are the R primary colours, and the brightness adjusted value of R primary colours be on the occasion of;

If the T point is positioned at little triangle GWP or RWN, confirm that then primary colours to be adjusted are the B primary colours, and the brightness adjusted value of B primary colours be on the occasion of;

If the T point is positioned at little triangle RWM or BWP, confirm that then primary colours to be adjusted are the G primary colours, and the brightness adjusted value of G primary colours be on the occasion of;

If T point overlaps with the extended line of BW line segment perhaps less than setting threshold, confirm that then primary colours to be adjusted are the B primary colours, and the brightness adjusted value of B primary colours be on the occasion of;

If T point overlaps with the extended line of RW line segment perhaps less than setting threshold, confirm that then primary colours to be adjusted are the R primary colours, and the brightness adjusted value of R primary colours be on the occasion of;

If T point overlaps with the extended line of GW line segment perhaps less than setting threshold, confirm that then primary colours to be adjusted are the G primary colours, and the brightness adjusted value of G primary colours be on the occasion of.

At step S906, finish this color correction.Correction module 403 no longer sends the brightness adjusted value of primary colours to projection module 402, projection module 402 will be kept the current luminance primary of projection light source.

A kind of concrete internal structure sketch map of embodiment of the invention projecting apparatus, shown in figure 11, comprising: photographing module 401, projection module 402, correction module 403, authentication module 404.

Wherein, the structure function of photographing module 401 is said identical with before, repeats no more here.

Specifically can comprise geometric distortion judging unit 1101 and cross-color judging unit 1102 in the authentication module 404.

Geometric distortion judging unit 1101 is used for photographic images that photographing module 401 is obtained, carries out geometric distortion and judges, and the geometric distortion judged result is sent to correction module 403.Geometric distortion judging unit 1101 carries out the method for geometric distortion judgement previously in identical described in the step S803, repeats no more here.Cross-color judging unit 1102 is used for photographic images that photographing module 401 is obtained, carries out cross-color and judges, and the cross-color judged result is sent to correction module 403.Cross-color judging unit 1102 carries out the method for cross-color judgement previously in identical described in the step S804, repeats no more here.

Can comprise geometric correction processing unit 1103 and color correction process unit 1104 in the correction module 403.Geometric correction processing unit 1103 is used to receive the geometric distortion judged result that geometric distortion judging unit 1101 sends, and according to the geometric distortion judged result, carries out geometric correction and handle.Particularly, if the geometric distortion judged result is distortion, 1103 pairs of original images of geometric correction processing unit carry out geometric correction to be handled, the image after obtaining proofreading and correct, and the image after will proofreading and correct sends to projection module 402 and carries out Projection Display; If the geometric distortion judged result is undistorted, then geometric correction processing unit 1103 needn't carry out the geometric correction processing, directly original image is sent to projection module 402 and carries out Projection Display.1103 pairs of original images of geometric correction processing unit carry out geometric correction to be handled, and the method that details among the method for the image after obtaining proofreading and correct and the step S503-S505 before is identical, repeats no more here.

Color correction process unit 1104 is used to receive the cross-color judged result that cross-color judging unit 1102 sends; And, carry out color correction process according to the cross-color judged result.Particularly; If said cross-color judged result is distortion; Then: according to the chromaticity coordinates of background colour in hue coordinate system of the view field in the photographing module 401 current photographic images that obtain, and the relative position between the chromaticity coordinates of object color component in hue coordinate system, confirm primary colours to be adjusted; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to projection module 402; And; After the brightness of projection module 402 according to the corresponding primary colours of the said brightness adjusted value adjustment light source of waiting to adjust primary colours; Continue to obtain the photographic images of photographing module 401 current shooting; And the relative distance between the chromaticity coordinates of the background colour of the view field in determining the current photographic images that obtains of said photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate is is during less than set point; Continuation is according to the chromaticity coordinates of background colour in hue coordinate system of the view field in the photographing module 401 current photographic images that obtain, and the relative position between the chromaticity coordinates of object color component in hue coordinate system, determines primary colours to be adjusted; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to projection module 402.If the cross-color judged result is undistorted, then color correction process unit 1104 need not carry out any processing, and projection module 402 will be kept the current luminance primary of light source.Color correction process unit 1104 and photographing module 401 in the correction module 403; And the light source driving units in the projection module 402 1106 cooperates that to carry out the method flow that the method for color correction process and the correction module shown in Fig. 9 b 403, photographing module 401 and projection module 402 cooperations before carry out color correction process identical, repeats no more here.

Projection module 402 comprises image-driven unit 1105 and light source driving units 1106.Image-driven unit 1105 is used for carrying out projection according to the image that geometric correction processing unit 1103 sends.The image that geometric correction processing unit 1103 sends can be the image after proofreading and correct, or original image.Light source driving units 1106 is used for adjusting according to waiting of sending of color correction process unit 1104 brightness of corresponding primary colours of the brightness adjusted value adjustment light source of primary colours.

Since judgement of above-mentioned cross-color and color correction process, and do not rely on geometric distortion judgement and geometric correction processing, that is to say that projecting apparatus can only carry out cross-color judgement and correction under the situation of not carrying out the geometric distortion judgement and proofreading and correct.Therefore, in practical application, the authentication module of above-mentioned projecting apparatus also can be only to have the function that cross-color is judged, promptly only has cross-color judging unit 1102.Correction module also can be the function that only has color correction process, promptly only has color correction process unit 1104.And in the process step of trimming process as shown in Figure 8, also can only realize cross-color judgement and color correction process separately through step S801-S802, S804, S807.

The projecting apparatus of the embodiment of the invention is because through the analysis to the view field in the photographic images; Carrying out geometric correction handles or color correction process; Thereby the predetermined image that needn't have certain characteristic through projection is realized carrying out correct operation, thereby has been simplified the process of correcting orthographic projection image.

Because the projecting apparatus of the embodiment of the invention is in the process of carrying out geometric correction or color correction; The predetermined image that needn't projection has certain characteristic; Therefore, above-mentioned S501-S507 step, perhaps the S801-S807 step not only can be carried out trimming process at the baseline of projection; Also can be in normal projection process; Obtain photographic images in real time through photographing module, authentication module can carry out geometric distortion to photographic images in real time and judge that perhaps cross-color is judged, correction module can carry out geometric correction in real time to be handled or color correction process.Therefore, the projecting apparatus of the embodiment of the invention and projected picture correcting method thereof can carry out geometric correction or color correction more conveniently.

Because the projecting apparatus of the embodiment of the invention can be realized color correction, make the application scenario of projecting apparatus be not limited to the occasion of display screen for white.For the display screen of other color, like ecru etc., can pass through color adjustment, and make the image effect that projects identical with effect on projecting to white display screen, it is more convenient to make that projecting apparatus uses.

One of ordinary skill in the art will appreciate that all or part of step that realizes in the foregoing description method is to instruct relevant hardware to accomplish through program; This program can be stored in the computer read/write memory medium, as: ROM/RAM, magnetic disc, CD etc.

The above only is a preferred implementation of the present invention; Should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; Can also make some improvement and retouching, these improvement and retouching also should be regarded as protection scope of the present invention.

Claims (10)

1. projected picture correcting method comprises:

By photographing module the view field that projecting apparatus projects on display screen is taken, obtain photographic images;

After correction module receives said photographic images,, determine corresponding geometric correction parameter according to the view field in the said photographic images; And use the image after said geometric correction parameter obtains proofreading and correct as operation transform to the original image that needs projection;

By the image projection of projection module after with said correction to display screen.

2. the method for claim 1 is said according to the view field in the said photographic images, determines corresponding geometric correction parameter to be:

Said correction module is determined corresponding geometric correction parameter according to the position coordinates on four summits of said view field.

3. method as claimed in claim 2, the position coordinates on said four summits according to said view field is determined corresponding geometric correction parameter and is comprised:

According to the position coordinates on four summits of said view field, and the position coordinates of proofreading and correct four summits of rectangle, calculate the geometric correction parameter.

4. method as claimed in claim 3, the position coordinates on said four summits according to said view field, and the position coordinates of proofreading and correct four summits of rectangle calculate the geometric correction parameter and comprise and utilize following formula to come the computational geometry correction parameter:

$\left[\begin{array}{c}{x_i}^{\&prime;}\\ {y_i}^{\&prime;}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{U\; v}\right]\left[\begin{array}{c}{x}_i\\ y_i\end{array}\right]}$ (formula 1)

Wherein, i is the integer between [1,4], (x ₁, y ₁), (x ₂, y ₂), (x ₃, y ₃), (x ₄, y ₄) be the position coordinates on four summits of said view field; (x ₁', y ₁'), (x ₂', y ₂'), (x ₃', y ₃'), (x ₄', y ₄') be the position coordinates on four summits of said correction rectangle; A, b, c, d, e, f, u, v are the geometric correction parameter that calculates.

5. the image after method as claimed in claim 4, the said geometric correction parameter of said use obtain proofreading and correct as operation transform to the original image that needs projection comprise according to following formula confirm with original image in the corresponding correction of locations of pixels coordinate after this locations of pixels coordinate:

$\left[\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\end{array}\right]=\frac{\left[\begin{array}{cc}a& b\\ c& d\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]+\left[\begin{array}{c}e\\ f\end{array}\right]}{1+\left[\mathrm{U\; v}\right]\left[\begin{array}{c}x\\ y\end{array}\right]}$ (formula 2)

In the formula, (x y) is a locations of pixels coordinate in the original image, and (x ' y ') is this locations of pixels coordinate after proofreading and correct.

6. projecting apparatus comprises:

Photographing module is used for the view field that projecting apparatus projects on display screen is taken, and obtains photographic images;

Correction module is used for the view field according to said photographic images, determines corresponding geometric correction parameter; And use said geometric correction parameter that the original image that needs projection is made operation transform, the image after obtaining proofreading and correct;

Projection module is used for the image projection after the said correction to display screen.

7. projecting apparatus as claimed in claim 6 is characterized in that,

Said correction module is used for the view field based on said photographic images; Determining corresponding geometric correction parameter comprises: based on the position coordinates on four summits of said view field and the position coordinates of proofreading and correct four summits of rectangle, calculate the geometric correction parameter;

Wherein, the position coordinates on four of said correction rectangle summits is for confirm in advance; Perhaps, the position coordinates on four of said correction rectangle summits is to confirm according to the position coordinates on four summits of view field in the said photographic images.

8. projecting apparatus as claimed in claim 7 is characterized in that, also comprises:

Authentication module is used for that said photographic images view field is carried out geometric distortion and judges, and the geometric distortion judged result is sent to said correction module; And,

Said correction module specifically is used for after definite said geometric distortion judged result is distortion, determines the view field in the said photographic images, and determining corresponding geometric correction parameter; And use said geometric correction parameter that the original image that needs projection is made operation transform, the image after obtaining proofreading and correct.

9. projecting apparatus as claimed in claim 8 is characterized in that, said authentication module is used for that also said photographic images view field is carried out cross-color to be judged, and the cross-color judged result is sent to said correction module.

10. projecting apparatus as claimed in claim 9 is characterized in that,

Said correction module also is used for after definite said cross-color judged result is distortion; According to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system, confirm primary colours to be adjusted; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to said projection module; Said brightness adjusted value is for confirm in advance; And,

Said projection module also is used for the brightness according to the corresponding primary colours of the said brightness adjusted value adjustment light source of waiting to adjust primary colours; And,

Said correction module also is used at the photographic images that continues to obtain said photographing module current shooting; And the relative distance between the chromaticity coordinates of the background colour of the view field in determining the current photographic images that obtains of said photographing module in hue coordinate system and the chromaticity coordinates of object color component in hue coordinate is is during less than set point; Continuation is determined primary colours to be adjusted according to the background colour of the view field in the current photographic images that obtains of said photographing module chromaticity coordinates and the relative position between the chromaticity coordinates of object color component in hue coordinate system in hue coordinate system; And the brightness adjusted value of adjusting primary colours of waiting that will determine sends to said projection module.

Images