Patent Publication Number: US-2011063293-A1

Title: Image processor

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2009-213275, filed on Sep. 15, 2009, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Exemplary embodiments described herein relate to an image processor. 
     BACKGROUND 
     A 3D-display for displaying three dimensional vision provides stereoscopic vision to observers by displaying an image having disparity difference for both eyes. 
     The 3D-display with multi viewpoints, for example, providing stereoscopic image effect for the observers in a plural positions is proposed as the 3D-display. 
     A method for drawing and retaining binocular images corresponding to a number of the viewpoint positions of the observers is adopted in the 3D-display. 
     Therefore, image processing load, memory consumption amount, transaction of system bus or the like are increased with increasing a number of the viewpoint positions corresponded to observers, so that a problem in which hardware constitution load is enlarged is generated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing a structure of a display system including an image processor according to an embodiment; 
         FIG. 2  is a block diagram showing a structure of an image generator according to the embodiment; 
         FIG. 3  is a conceptual diagram showing data and depth information of a material image retained in memories; 
         FIG. 4  is an explanation view showing generation of a disparity by a disparity generator; 
         FIG. 5  is an explanation view showing compositing a binocular image by an image compositor; 
         FIG. 6  is a flow chart explaining an operation order of the image processor. 
     
    
    
     DETAILED DESCRIPTION 
     According to one embodiment, an image processor is disclosed. The image processor can include a material image drawing portion drawing a material image, the material image is a material for a 3D display, a material image memory portion storing data of the material image drawn by the material image drawing portion, and an image generator generating image data for the 3D display on a basis of the data of the material image read from the material image memory portion, depth information configured to the material image, and viewpoint position information preliminary configured, and outputting the image data to a display portion. 
     An embodiment of the present invention will be described below in detail with reference to the attached drawings mentioned above. Throughout the attached drawings, similar or same reference numerals show similar, equivalent or same components. 
     Embodiment 
       FIG. 1  is a block diagram showing a structure of a display system including an image processor  1  according to an embodiment. The display system includes the image processor  1  and a 3D-display  2 . The image processor  1  includes a drawing portion  3 , a memory portion  4  and an image generator  5 . The image processor  1  generates image data for 3D display and output the image data to the 3D-display  2 . The 3D-display  2  acts as a display portion for 3D display. 
     The drawing portion  3  acts as a material image drawing portion which draws a material image being material for 3D display. The memory portion  4  acts as a material image memory portion which stores both data of the material image (called material image data hereafter) drawn by the drawing portion  3  and depth information set to the material image. The material image data are color data of each pixel constituting the material image, for example, R, G, and B signal values of three primary colors. The depth information is position information of images configured on a depth direction in a 3D direction, for example, is configured by users. The image generator  5  acts as a 3D image generator which generates the image data for 3D display on a basis of the material image data read out from the memory portion  4 , depth information and viewpoint position information. The viewpoint position information is the position information of the views which have a capability of stereoscopic view of the 3D display. Position and number of the viewpoint position information can be preliminary configured by a specification of the 3D-display  2 . 
       FIG. 2  is a block diagram showing a structure of an image generator. The image generator  5  includes a disparity generator  11 , a viewpoint position counter  12  and an image compositor  13 . The image generator  5  includes a disparity generator  11 , a viewpoint position counter  12  and an image compositor  13 . The disparity generator  11  acts as a disparity portion generating a binocular image of each viewpoint position in corresponding the depth information and the viewpoint position information. The binocular image means including both a left eye image and a right eye image. The disparity means is an angle difference of a sight line vector when both the right and the left eyes look a point. The viewpoint position counter  12  outputs a count value C representing the viewpoint position as viewpoint position information. The image compositor  13  composites left eye images, each left eye image corresponds to each material image, and composites right eye images, each right eye image corresponds to each material image, so as to generate the image data for the 3D display. 
     Next, operation of the image processor  1  is explained.  FIG. 3  is a conceptual diagram showing data and depth information of a material image retained in memories. In  FIGS. 3A and 3B , a memory area MA stored the material image data and a memory area MB stored the depth information are illustrated, respectively. by using the drawing portion  3 , for example, a material image  1   a  with infinity in the depth as a background, a material image  2   a  with a depth DA which is set to be 0&lt;DA&lt;infinity, the material image  2   a  being a elliptical body which is called an object α hereafter and a material image  3   a  with a depth DB which is set to be 0&lt;DB&lt;infinity, material image  3   a  being an isosceles triangle body which is called an object β hereafter. 
     Each of data of the material images la,  2   a ,  3   a  is stored in each frame buffer in the memory area MA. 
     Each of data of the depth information  1   b  with the depth of infinity, the depth information  2   b  with the depth being DA and depth information  3   b  with the depth being DB corresponding to material images  1   a ,  2   a  and  3   a  are stored in each depth buffer of the memory area MB. 
     The image generator  5  as shown in  FIG. 2  reads the data of each frame buffer stored in the memory area MA and reads the data of each depth buffer stored in the memory area MB one line by one line to the parallel direction, respectively. The data read in the image generator  5  is input in the disparity generator  11 . Further, the count value C from the viewpoint position counter  12  is input in the disparity generator  11 . Further, the depth information is not restricted to store in the memory portion  4 . For example, the depth information may be configured as a fixed value of each plane to the image generator  5 . 
       FIG. 4  is an explanation view showing generation of a disparity by a disparity generator  11 . The binocular image is generated corresponding to the data of the depth buffer read from the memory area MB and the count value C generated in the disparity generator  11  on the basis of the data of each frame buffer read from the memory area MA. 
     The disparity generator  11  generates the left eye image  1   c  and the right eye image  1   d  in the background from the data of the material image  1   a  and the depth information  1   b . As the depth information  1   b  is infinity, a disparity shift amount s 1  between the images for both eyes  1   c ,  1   d  are set to be zero. The disparity generator  11  generates an image for the left eye  2   c  and an image for the right eye  2   d . A disparity shift amount s 2  between the image for the left eye  2   c  and the image for the right eye  2   d  of the object β is calculated corresponding to the depth information  2   b  and the viewpoint position information input as the count value C. The image for the left eye  2   c  is generated by shifting the object α to the right direction horizontally to the material image  2   a  as the disparity shift amount s 2 . The image for the right eye  2   d  is generated by shifting the object α to the left direction horizontally to the material image  2   a  as the disparity shift amount s 2 . 
     The disparity generator  11  generates an image for the left eye  3   c  and an image for the right eye  3   d  of the object β from data of the material image  3   a  and the depth information  3   b . A disparity shift amount s 3  between the images for the left eye  3   c  and the right eye  3   d  is calculated corresponding to the depth information  3   b  and the viewpoint position information input as the count value C. The image for the left eye  3   c  of the object β is generated by shifting the object β to the right direction horizontally to the material image  3   a  as the disparity shift amount s 3 . The image for the right eye  3   d  is generated by shifting the object β to the left direction horizontally to the material image  3   a  as the disparity shift amount s 3 . In General, as the disparity becomes larger when the position of the body viewed from the viewpoint is nearer, a relationship between s 2 &lt;s 3  is established between the disparity shift amount s 2  and the disparity shift amount s 3 . 
     The disparity generator  11  generates the binocular images  1   c ,  1   d  for the background, the binocular images  2   c ,  2   d  of the object α and the binocular images  3   c ,  3   d  of the object β, when each count value C is input. The shifts of the objects α, β in generating the binocular images  2   c ,  2   d ,  3   c ,  3   d  to the material images  2   a ,  2   b  are performed by changing the relationship between the coordinate as a standard and the image corresponding to the disparity shift amount s 2 , s 3 . 
       FIG. 5  is an explanation view showing compositing the binocular image by an image compositor. For example, viewpoints  1 - n  are configured as the view point position information where each of the viewpoints  1 - n  is set to be at a different position. The image compositor  13  generates an image for the left eye  1   e  to the viewpoint  1  by compositing the left eye image  1   c  of the object α in the background, the left eye image  2   c  of the object α and the left eye image  3   c  of the object R on the viewpoint  1  which is input as the viewpoint position information as the count value C. Further, the image compositor  13  generates an image for the right eye if to the viewpoint  1  by compositing the right eye image  1   d  of the object α in the background, the right eye image  2   d  of the object α and the right eye image  3   d  of the object β on the viewpoint  1 . The image compositor  13  composites binocular images  1   e ,  1   f  by a compositing treatment to interpose the object β, the object α, and the background from the front side to the back side corresponding to the depth information  1   b ,  2   b ,  3   b.    
     Hidden surface removal treatment which erases a region not shown from a viewpoint blanked by another body or a face, for example, is adopted in compositing images by the image compositor  13 . The image compositor  13  may adopt a blend which translucently composites a plural images by using β value. The image compositor  13  composites left eye images  2   e -ne and right eye images  2   f -nf on the viewpoints  2 - n  as the same as the viewpoint  1 . In such a manner, the image compositor  13  generates data of binocular images  1   e -ne and  1   f -nf in each viewpoint position as image data for 3D display. 
       FIG. 6  is a flow chart explaining an action order of the image processor. The material image is drawn by the drawing portion  3  in step S 1  to read the material image data into the memory  4  in step S 2 . A start of the 3D display is instructed, for example, by operating a switch or the like to read out the material image data and depth information to the image generator  5  in step S 3 . 
     Next, a disparity component corresponding to a relation between the coordinate and the image is shifted in step S 4  to generate binocular image in the disparity generator  11 . The disparity generates on each viewpoint by calculating the disparity shift amount on the basis of the viewpoint position information. The depth information is also used in calculating the disparity shift amount. When the binocular images of all the viewpoints are generated, the image data for 3D-display are generated by compositing the images in the image compositor  13  in step S 5 . The depth information is also used in calculating the compositing treatment in the image compositor  13 . The image compositor  13  stores the image data for 3D-display into a line buffer in step S 6 . The image compositor  13  serially outputs the image data for 3D-display into the 3D-display  2  in step S 6 . The image generator  5  serially reads out the image data as the 3D-display  2  stored in the line buffer in step S 7 . 
     In the image processor  1 , only material image is drawn by the drawing portion  3 . On the other hand, the image related to each viewpoint is generated by the image generator  5 . Consequently, image processing load can be decreased compared to a case that all the images on each viewpoint are drawn. Further, the data of only the material images are retained in the memory portion  4 . On the other hand, only one line of the line buffer in the image generator  5  retains the data of the image data for 3D-display. Further, only the data with respect to the memory portion  4  are retained, and only the data according to one line in the image generator  5  are retained on the image data for 3D display. The frame buffer with less the viewpoints may be prepared in the image processor  1 . Therefore, memory consumption can be decreased in a case that the frame buffer for both eyes is necessary to be full number of the viewpoints. Further, only the data read and write between the drawing portion  3  and the memory portion  4 , and the image generator  5 . Accordingly, transaction of the bus can be decreased as compared to a case that all the image data write and read. 
     As mentioned above, decreasing the load in drawing processing, the memory consumption, the transaction in the system bus can be decreased in increasing a number of the viewpoint positions corresponding to the 3D-display. Consequently, the method mentioned above has an effect that a load of the hardware constitution can be decreased in the 3D-display corresponding to many viewpoint positions. The image processor  1  can be constituted by slightly changing or adding to a circuit using conventional technology such as a plane composition or the like. Further, the treatment for generating disparity can be restricted to the unit of one line in the display by the construction in which the disparity is generated in restriction of horizontal migration on the image. As a result, assembly cost of the hardware can be improved. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel devices described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the devices described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalent are intended to cover such forms or modifications as would fall within the scope and sprit of the inventions.