The present invention relates to an image processing device and a system using the same, which is capable of performing graphics processing, drawing processing and display processing at high speed.
More specifically, the present invention relates to an information terminal machine, such as a facsimile machine, printer, graphics device, portable personal terminal machine, navigation machine and amusement device, and to an image processing system which performs inputting, processing, editing, accumulating, communicating, outputting and displaying of image data using the information terminal machine.
In particular, the present invention relates to an image processing device and a system using the same which can minimize the amount of data being transferred between a memory device and the image processing device to thereby perform high speed processing.
Further, in particular, the present invention relates to a graphics drawing method, and to an image processing device and a system using the same in which, in order to minimize the amount of data being transferred between a memory device and the image processing device, reduces drawing suppression processing (hidden surface processing) due to graphics overlapping, and which, in particular, performs complex image processing and three dimensional graphics display processing at high speed.
Further, in particular, the present invention relates to a method which suppresses an increase of components in an image processing system having high speed access to a memory, thereby reducing the construction cost thereof.
Various conventional systems for effecting data transfer between a memory, which holds image data, and an image data processor and/or an image processing device, which processes the image data, have been developed. However, these conventional systems have inherent problems with regards to their processing speed, such as for accessing and drawing, in that high speed processing and real time processing in a device or a system which is required to process a great amount of data have proven to be insufficient.
A proposal in which image data transferred between a memory device and an image processing device is drawn and processed in blocks representing a pixel aggregate is disclosed in Andy Goris et al. xe2x80x9cA Configurable Pixel Cache for Fast Image Generationxe2x80x9d (IEEE, Computer Graphics and Application, May 1987, pp. 24-32), which is hereinafter referred to as the Goris et al. publication.
According to Goris et al., pixel data is fetched in blocks on demand into a pixel cache, and a drawing process is executed such that a prefetch effect is limited within a block unit.
Even in a case when a drawing processing is performed while crossing the boundary between blocks, since the pixel data is generated via a common rasterizing mode, a prefetch for pixel data in the subsequent block is started.
Therefore, if the capacity of the pixel cache is small, in response to the prefetch of the pixel data in the subsequent block, the pixel data in the previous block is first pushed out of the pixel cache and then the pushed out pixel data again needs to be accessed via rasterization, which causes a problem in that frequent memory access is necessitated.
In particular, when a coloring-up darkening process is performed for a triangle, although it is necessary to generate pixel data two-dimensionally and to process the same, the memory access is performed one-dimensionally; therefore, even when performing a drawing processing of nearby pixel data, the prefetched data as indicated above cannot be utilized, which causes an inefficient memory access. In other words, it causes a problem in that an additional memory band width is necessitated.
Further, in a graphics architecture in which a memory area for drawing processing is arranged in a main memory, a sufficient memory band width has to be provided which causes a problem in that the memory can not be efficiently used.
A three-dimensional graphics display device generally uses a display method in which an object to be displayed is divided into small three-dimensional graphics, such as triangles and quadrangles, and is modeled; a geometrico arithmetic operation is performed on these small graphics based on their viewed direction; and, based on the resultant arithmetic values, the respective graphics are projected on the two dimensional coordinate of a display device, such as a CRT. At this time, however, it is required to check for overlapping of the respective graphics in their depth direction and to prevent drawing of hidden graphics on a frame buffer.
As a conventional method of judging graphics, an overlapping Z buffer algorithm, in other words a depth buffer algorithm, is generally used. This conventional method is, for example, explained in W. M. Newman et al. xe2x80x9cDialog Type Computer Graphics (II) 2nd editionxe2x80x9d translated by Setsuo Ohsuga (McGraw-Hill Book Company, 1984, pp. 483-441), which is hereinafter referred to as the Newman et al. publication. According to this method, depth information is provided for respective pixels every time. When drawing respective pixels, depth information of a pixel to be drawn is compared with the depth information of already drawn pixels, and when the pixel to be drawn is located closer to the screen, the pixel is permitted to be drawn, and conversely, when the pixel to be drawn is located deeper than the already drawn pixel, the drawing of the pixel is prevented.
Another method in which overlapping of graphics is checked via geometric calculation is, for example, explained on pages 442-443 of the Newman et al. publication. In this method, a circumscribed rectangle is defined for each of the polygons to be drawn and overlapping of these circumscribed rectangles is judged; however, when the respective circumscribed rectangles do not overlap each other, the judgment with regard to their depth is omitted.
On the other hand, a method which avoids the necessity of the Z buffer is explained in James D. Foley et al. xe2x80x9cFundamentals of Interactive Computer Graphicsxe2x80x9d translated by Atsumi Imamiya (Published by Japan Computer Association, 1982, pp. 569-572), which is hereinafter referred to as the Foley et al. publication. This method is based on a depth sort algorithm in which the drawing is started from the graphic in the deepest location and graphics close to the viewer are successively drawn while overlapping graphics.
Further, U.S. Pat. No. 4,303,986 discloses a provision of a selective writing means for a memory which stores two dimensional images.
In the method disclosed in the Newman et al. publication, a Z buffer algorithm is used for judgment of graphics overlapping, so that this method necessitates depth information for every pixel and therefore requires a Z buffer (frame buffer) of large capacity. For example, assuming a standard system having 34 bits for color information and 16 bits for the Z buffer with a screen having 1024xc3x97768 pixels, a memory of about 4M bits in total is necessitated, among which a memory of about 1.4M bits is needed for the Z buffer algorithm and a memory of about 1.6M bits is needed for the Z buffer. Further, in the conventional Z buffer algorithm, the same pixel is accessed as many times as the number of graphics that overlap, and every time a drawing is performed, the Z buffer content has to be read and the read Z value has to be compared, among which comparison only one comparison result is significant. For this reason, useless memory access is necessitated, which makes an improvement of drawing performance difficult.
On the one hand, the method disclosed in the Foley et al. publication, which avoids any need for the Z buffer, is effective with regard to memory capacity reduction; however, since graphics are successively drawn in an overlapping manner from the graphic in the deepest location, the graphic closest to the viewer sometimes can not be drawn depending on the number of graphics to be drawn. Thus, this method can not be applied to a system which requires a real time performance.
With regard to a conventional image processing system, for example, JP-A-5-258040 (1993) and JP-A-5-120114 (1993) disclose examples of a data processing system which makes use of a synchronous DRAM permitting high speed data transfer.
However, these image processing systems are not practical because they require excessive time when a plurality of image processings are performed via multi tasks. Further, when a bus control is performed via a time slot method by making use of a synchronous DRAM, a mishit control is frequently generated which causes a problem in that an increase of the throughput is limited.
Further, GAIN (Technical Report Published by Hitachi, Ltd. Semiconductor Division, No. 96, 1993.1, pp. 6-11) discloses an example for reducing the size and cost of the device by making use of a built-in RISC (Reduced Instruction Set Computer). However, the paper is silent with regard to a specific memory access method and bus utilization method which realize a high speed image processing.
Still further, JP-A-4-107056 (1992) discloses a high speed processing method in which a bus which transfers image data from a decoder to a printer is made independent from a MPU bus.
Still further, in a conventional facsimile machine, an example of an image processing system is disclosed in Shuichi Fujikura et al. A Development of a LSI for Facsimile Image Processingxe2x80x9d (Oki Denki Research and Development Report, October, 1992. No. 156, vol. 59, No. 4, pp. 65-70) having a processor and high speed memory dedicated for image processing in an image input and output unit, and in which data distortion is corrected to thereby realize images of high quality. However, in association with gathering of control units, each formed by a one chip microcomputer, the space rate occupied by the image processing unit increases, which adversely affects the cost thereof.
Still further, the image processing system in a recent business use facsimile machine tends to accelerate high image quality, high processing speed and large memory capacity such that LSIs dedicated for image processing and for coding are frequently constituted to have their own respective SRAMS. Accordingly, there arises a problem of increased cost of the devices.
Still further, a conventional image processing system used for a facsimile machine, a printer and a graphics device, as disclosed in JP-A-61-261961 (1986), has a SRAM (static memory) used for local processing by referring to nearby pixels at high speed and a DRAM (dynamic memory) used for storing data, such as symbol data and font data, operating at low speed, but having a large memory capacity. Therefore, the impossibility of integrating the above two types of memories is a significant problem from the point of view of device size reduction, integration into a single LSI, device constitution, device cost and product series development.
Still further, one of the reasons why high speed image processing could not be achieved with the above conventional art is that the image inputting and outputting processing and the communication processing function are required to have an extremely high real time property as well as a high speed bus throughput of about 4-20 MB/s such that their processings have to be performed via a dedicated processor and a local processing use dedicated memory independent from a main memory.
Due to the development of the semiconductor micro-machining technology and improvements in microprocessor architecture, a high speed processor, such as a RISC, and a device having an operating speed more than 100 MHz, such as a RAMBUS and synchronous DRAM, have appeared on the market. For example, the synchronous DRAM has already begun to draw attention as a memory having a large capacity operable at high speed. In contrast to the conventional DRAM, a synchronous DRAM can input and output data, address and control signals in synchronism with clocks to thereby realize a high speed data transfer comparable with the conventional SRAM, in addition to the fact that a synchronous DRAM having a larger memory capacity than the conventional DRAM can be realized at a low cost.
There are marked characteristics in image communication and processing, including advantageous characteristics with regard to the construction thereof which involve regularity in address renewal, such as the continuity of the address to be processed, easy previous forecasting of processing quantity and simple processing content and limited nearby influence of the processed result, and disadvantageous characteristics representing an intense real time requirement and a possible system break-down when not completing the processing within a predetermined time. However, no devices and systems have been proposed until now which optimize the processing in view of the above advantageous and disadvantageous characteristics, so that it is necessary to provide a device and a system therefor which take into consideration the above advantageous and disadvantageous characteristics.
An object of the present invention is to provide a device which processes a great quantity of data at high speed and in real time, and a system using the device.
Another object of the present invention is to provide an image processing device which minimizes the amount of data being transferred between a memory device and the image processing device and performs high speed processing, and a system using the device.
Still another object of the present invention is to provide a graphics drawing method which, in order to minimize the quantity of data transfer between a memory device and an image processing device, reduces drawing suppression processing (hidden surface processing) due to overlapping of graphics and, in particular, performs complex image processing and three dimensional graphics display processing at high speed, and an image processing device and a system using the method.
A further object of the present invention is to provide a device and a system which avoid an increase of components in an image processing system which accesses a memory at high speed so as to achieve low cost.
A still further object of the present invention is to provide a graphics drawing method and device, and a three dimensional graphics display method and device which make it possible to reduce the capacity of a data storage area in which drawing use graphics data is to be stored.
A still further object of the present invention is to provide a graphics drawing method and device, and a three dimensional graphics display method and device which permits high speed drawing processing.
A still further object of the present invention is to provide a high speed image processing system of low cost by integrating an image inputting and outputting process, a coding and decoding process and a communication process, which are conventionally processed independently, and further by integrating a high speed local processing use memory and a large capacity memory.
An aspect of the invention is characterized by the fact that, based on the processing status of pixel data of every one of respective rows in a block buffer which holds pixel data accessed from a memory by a block unit, a command with regard to image processing is executed and the processing of the pixel data is performed.
Further, an aspect of the present invention is characterized by the fact that, based on the processing status information of the pixel data to be processed, the pixel data to be processed next is specified.
Further, an aspect of the present invention is characterized by the fact that the device according to the present invention comprises a command buffer which holds commands indicating processings relating to drawings, a block buffer which accesses pixel data held in a memory in every block unit and holds the same, a pixel data processing unit which executes the processing of the pixel data in the block buffer based on the command and detects the processing status of the pixel data at boundaries of the respective rows in the block buffer and a status register which holds processing status information indicating the processing status of the pixel data at the boundaries of the respective rows and, in that the processing of the pixel data in each of the blocks is executed based on the commands and the processing status information.
An aspect of the present invention is characterized by the fact that, since the commands relating to the image processing are executed and the processing of the pixel data is performed on the basis of the processing status of the pixel data in the block buffer, all of the pixel data in a block unit can be processed without recourse to the order of the raster development, the number of access times between a memory and an image processing processor can be reduced and a high speed image processing and drawing processing can be realized.
An aspect of the present invention is characterized by the fact that, since the pixel data to be processed next is specified on the basis of the processing status information of the pixel data to be processed, all of the pixel data in a block unit can be processed without recourse to the order of the raster development, the number of access times between a memory and an image processing processor can be reduced and a high speed image processing and drawing processing can be realized.
An aspect of the present invention is characterized by the fact that, since the processing status information of the pixel data to be processed is held in every row unit within each of the blocks, the capacity of the status register can be reduced and the pixel data to be processed next can be specified.
An aspect of the present invention is characterized by the fact that, since the processing status information of the pixel data to be processed is held in every pixel data at the boundary with an adjacent block, the capacity of the status register can be reduced and the pixel data to be processed next can be specified.
An aspect of the present invention is characterized by the fact that, in order to reduce information for judging overlapping of graphics, a control data writing region is provided indicating whether or not a pixel is already drawn in a data storage region storing drawing use graphics data, control data flags are stored in the control data writing region, and, when the information of the control data writing region indicates that the drawing is not completed, the drawing is performed and otherwise the drawing is prohibited.
An aspect of the present invention is characterized by the fact that, when drawing successively a plurality of pixels based on the data of pixel groups relating to a three dimensional image, a control data writing region is provided indicating whether or not a pixel is already drawn in a data storage region storing drawing use graphics data of the respective pixels, and, when drawing of the respective pixels is commanded, a pixel to be newly drawn is designated depending on the control data in the control data writing region, the designated pixels are successively drawn and control data indicating that the drawing is completed is written in the control data writing region relating to the pixel of which drawing is completed.
An aspect of the present invention is characterized by the fact that, when drawing successively a plurality of pixels based on the data of pixel groups relating to a three dimensional image, a control data writing region is provided indicating whether or not a pixel is already drawn in a data storage region storing drawing use graphics data of the respective pixels, when drawing of the respective pixels is commanded, and only when control data indicating that a pixel is not yet drawn is added in the drawing use graphics data of the respective pixels extracted from the data storage region, will the drawing of the pixel be executed and control data indicating that the drawing is completed be added in the drawing use graphics data for the pixel and stored in the data storage region; and, when control data indicating that the pixel is already drawn is added in the drawing use graphics data of the respective pixels extracted from the data storage region, redrawing of the pixel is prohibited.
An aspect of the present invention is characterized by the fact that the device according to the present invention is applicable to devices in which, based on the data of pixel groups relating to images of a plurality of polygons, the pixels of the respective polygons are successively drawn.
An aspect of the present invention is characterized by the fact that the device according to the present invention is applicable to devices in which a graphics group in a form of graphics list containing image information of pixel groups relating to a plurality of polygon graphics having different depths is sorted according to the depth information relating to the depth of the respective graphics and the pixels of the respective graphics are successively drawn according to the order of the sorting.
Further, an aspect of the present invention uses a method in which, when performing drawing based on a graphics list containing image information of pixel groups relating to a plurality of polygon graphics having different depths, the graphics in the graphics list (display list) to be displayed are sorted in advance from those closest to the viewer of the screen and the respective graphics are drawn according to the order of the sorting. More specifically, an aspect of the present invention is characterized by the fact that a graphics group in a form of a graphics list containing image information of pixel groups relating to a plurality of polygon graphics is sorted according to the depth information relating to depth of the respective graphics, the respective graphics are selected according to the order of the sorting, whether or not the drawing region of a polygon belonging to the selected graphics is contained in a drawing region of a polygon belonging to a graphic having a higher sorting order is judged according to the image information, a graphics which is judged as contained in the drawing region by the judgment is deleted from the graphics list, and when the drawing for the respective pixels of the graphics judged to be not contained in the drawing region by the judgment is commanded, the drawing for the respective pixels of the graphics is executed based on the image information.
Further, an aspect of the present invention is characterized, in that in the course of executing the above graphics drawing method, when a drawing for the respective pixels of the graphics judged as not contained in the drawing region, judgment processing of the graphics list is commanded, the drawing use graphics data of the respective pixels are extracted from the data storage region storing the drawing use graphics data of the respective pixels only when a flag indicating that a pixel is not yet drawn is added in the extracted drawing use graphics data, the drawing for the pixel is executed and a flag indicating that the drawing is completed is added in the drawing use graphics data of the pixel and is stored in the data storage region; and, when a flag indicating that a pixel is already drawn is added in the drawing use graphics data of the respective pixels extracted from the data storage region, the redrawing of the pixel is prohibited.
An aspect of the present invention is characterized, by the fact that, when judging specifically the drawing region of a polygon belonging to the graphic list, a circumscribed rectangle for a polygon belonging to the graphics list and an inscribed rectangle for the polygon are respectively provided in correspondence to the drawing region, and whether or not a circumscribed rectangle relating to a selected graphic is hidden by an inscribed rectangle relating to a graphic having a higher order of sorting is judged.
Further, an aspect of the present invention is characterized by the fact that a method is used in which a plurality of groups, each containing one image unit consisting of a plurality of polygons, are formed depending on their depth, graphics lists containing image information of the pixel groups corresponding to the polygon graphics are produced for every one of the respective groups, and when judging an overlapping of a graphic belonging to a graphics list, circumscribed rectangles for the graphics of the respective groups and inscribed rectangles for the graphics of the respective groups are respectively provided in correspondence to the drawing region; and, whether or not a circumscribed rectangle relating to the graphic of the selected group is hidden by an inscribed rectangle relating to a graphic of a group having a higher order of sorting is judged.
Further, an aspect of the present invention is characterized by the fact that, in order to realize a high speed drawing processing by eliminating a Z comparison in a drawing processing based on a graphics list containing image information of pixel groups corresponding to a plurality of polygon graphics having different depths, the drawing regions for a plurality of graphics belonging to the graphics list are respectively provided, when drawing of the respective graphics is commanded, whether or not the drawing regions relating to the respective graphics belong to a drawing region relating to a graphic having a higher order of drawing is judged and a drawing for a graphic judged as not belonging to the drawing region by the judgment is executed according to the image information.
An aspect of the present invention is characterized by the fact that, based on a graphics list containing image information of the pixel groups corresponding to a plurality of polygon graphics having different depths, drawing regions of a plurality of graphics belonging to the graphics list are provided, when drawing for the respective graphics is commanded, whether or not the drawing regions relating to the respective graphics belong to a drawing region relating to a graphic having a higher order of drawing is judged. A drawing of the graphic judged as not belonging to the drawing region by the judgment is executed according to the image information, when a drawing for the respective pixels of the graphic judged as belonging to the drawing region by the judgment is commanded, the drawing use graphics data of the respective pixels are extracted from the data storage region storing the drawing use graphics data of the respective pixels, and only when a flag indicating that a pixel is not yet drawn is added in the extracted drawing use graphics data, will a drawing for the pixel be executed and a flag indicating that the pixel is already drawn is added in the drawing use graphics data of the pixel be added and stored in the data storage region; and, when a flag indicating that the pixel is already drawn is added in the drawing use graphics data of the respective pixels extracted from the data storage region, redrawing of the pixel is prohibited.
An aspect of the present invention is characterized by the fact that a plurality of groups, each containing a plurality of polygons as an image unit, are formed, depending on their depths, and a graphics list containing image information of pixel groups corresponding to polygon graphics of the respective groups and circumscribed rectangles for the graphics of the respective groups in the graphics list are respectively provided in correspondence to the drawing regions, when drawing for the graphics of the respective groups is commanded, whether or not the circumscribed rectangles relating to the graphics of the respective groups belong to a circumscribed rectangle relating to a graphic of a group having a higher order of drawing is judged. A drawing for the graphic of the group judged as not belonging is executed according to the image information, and when a drawing for the graphic of the group judged as belonging is commanded, the drawing use graphics data of the respective pixels are extracted from the data storage region storing the drawing use graphics data of the respective pixels of the graphic belonging to the group, and only when a flag indicating that a pixel is not yet drawn is added in the extracted drawing use graphics data, will a drawing for the pixel be executed and a flag indicating that the pixel already drawn is added in the drawing use graphics data of the pixel be added and stored in the data storage region; and, when a flag indicating that the pixel is already drawn is added in the drawing use graphics data of the respective pixels extracted from the data storage region, redrawing of the pixel is prohibited.
An aspect of the present invention is characterized by the fact that a method is used in which, in the course of executing a graphics drawing method eliminating Z comparison, in order to judge an overlapping of graphics belonging to a graphics list, circumscribed rectangles for a plurality of polygons are respectively provided in correspondence to the drawing regions, and drawing for the respective polygons is commanded, whether or not the circumscribed rectangles relating to the respective polygons belong to a circumscribed rectangle relating to a polygon having a higher order of drawing.
An aspect of the present invention is characterized by a three dimension graphics display method displaying a three dimensional image on a display screen according to the drawing use graphics data obtained through one of the above graphics drawing methods.
Further, an aspect of the present invention is characterized by the fact that a graphics drawing device, in which information required for judging overlapping of graphics is reduced, is constituted by a data storage means in which graphics data relating to two dimensional graphics is stored in correspondence to pixel groups, as well as control data indicating whether or not the respective pixels already drawn are stored; a data extracting means which extracts designated graphics data and control data from the data storage means based on the image information of the pixel groups corresponding to a plurality of polygon graphics; a graphics data producing means which, when the control data extracted by the data extracting means indicates that drawing of a pixel is not completed, new graphics data is produced according to the image information, and, when the control data extracted by the data extracting means indicates that drawing of a pixel is completed, the production of new graphics data is eliminated; a drawing means which draws the graphics data produced by the graphics data producing means on the pixel designated by the data storage means; and a control data providing means which provides data representing that the drawing of the pixel is completed for the control data of the pixel which has been drawn by the drawing means among the control data in the data storage means.
Further, an aspect of the present invention is characterized by the fact that the above device in which graphics are drawn based on the image information of the graphics list and in which information required for judging an overlapping of graphics is reduced, further comprises a graphics list storage means which stores a graphics list containing the image information of the pixel groups corresponding to a plurality of polygon graphics; a sorting means which sorts graphics groups in the graphics list stored in the graphics list storage means according to depth information relating to the depth of the respective graphics; and a means for transferring the image information relating to the sorted graphics by the sorting means to the data extracting means.
Further, an aspect of the present invention is characterized by the fact that a graphics drawing device in which only graphics not overlapping other graphics are extracted among the graphics list, comprises a data storage means in which graphics data relating to two dimensional graphics is stored in correspondence to pixel groups as well as control data indicating whether or not the respective pixels already drawn are stored; a graphics list storage means which stores a graphics list containing image information of the pixel groups corresponding to a plurality of polygon graphics; a sorting means which sorts graphics groups in the graphics list stored in the graphics list storage means according to depth information relating to the depth of the respective graphics; a region judgment means which judges, based on the image information, whether or not the drawing regions of polygons belonging to the sorted graphics by the sorting means are contained in a drawing region of a polygon belonging to a graphic having a higher order of sorting; a deleting means which deletes the graphics judged as contained by the region judgment means from the graphics list; a graphics data producing means which produces graphics data relating to graphics judged as not contained by the region judgment means for every one of the pixels according to the image information; and a drawing means which draws the graphics data produced by the graphics data producing means on the designated pixel in the data storage means.
An aspect of the present invention is characterized by the fact that the above graphics drawing device, in which only graphics not overlapping others are extracted from the graphics list, further comprises a rectangle providing means which respectively provides circumscribed rectangles for the polygons belonging to the sorted graphics by the sorting means and inscribed rectangles for the polygons while correlating the data to the drawing regions and a region judgment means which judges the drawing region according to the rectangles provided by the rectangle providing means.
An aspect of the present invention is characterized by the fact that the above graphic drawing device in which the graphics list storage means includes a plurality of groups each containing one image unit consisting of a plurality of polygons depending on their depth and stores for every one of the groups graphics list containing the image information of the pixel groups corresponding to the respective polygon graphics, further comprises a rectangle providing means which respectively provides circumscribed rectangles for the graphics of the groups belonging to the sorted graphics by the sorting means and inscribed rectangles for the graphics of the groups while correlating the data to the drawing regions and a region judgment means which judges the drawing region according to the rectangles provided by the rectangle providing means.
An aspect of the present invention is characterized by the fact that the graphics drawing device, in which Z comparison processing in the drawing processing is eliminated, comprises a data storage means which stores graphics data relating to two dimensional graphics while correlating the data to the pixel groups, as well as stores control data indicating whether or not the respective pixels are already drawn; graphics list storage means which includes a plurality of groups each containing one image unit consisting of a plurality of polygons depending on their depth and stores for every one of the groups a graphics list containing image information of the pixel groups corresponding to the respective polygon graphics; a sorting means which sorts the graphics groups in the graphics list stored in the graphics list storage means according to depth information relating to the depth of the respective graphics; a rectangle providing means which respectively provides circumscribed rectangles for graphics in a group belonging to the graphics of groups sorted by the sorting means and inscribed rectangles for the graphic in the group while correlating the data to the drawing regions; a region judgment means which judges whether or not the circumscribed rectangle relating to the graphic in the group sorted among the rectangles provided by the rectangle providing means is hidden by an inscribed rectangle belonging to a graphics in a group having a higher order of sorting; a graphics data producing means which produces for every one of the pixels graphics data relating to only the polygons in the graphics judged as not hidden by the region judgment means according to the image information; and a drawing means which draws the graphics data produced by the graphics data producing means on the pixel designated by the data storage means.
Similarly, an aspect of the present invention is characterized by the fact that the graphics drawing device comprises a data storage means which stores graphics data relating to two dimensional graphics while correlating the data to the pixel groups and storing control data indicating whether or not the respective pixels are already drawn; a rectangle providing means which, based on graphics list containing the image information of the pixel groups corresponding to a plurality of polygon graphics having different depths, provides circumscribed rectangles for the polygons belonging to the graphics list while correlating the data to the drawing regions; a region judgment means which judges whether or not the respective circumscribed rectangles provided by the rectangle providing means belong to a circumscribed rectangle having a higher order of drawing; a first graphics producing means which produces for every one of the pixels graphics data relating to the polygon judged as not belonging by the region judgment means; a data extracting means which, when judged as belonging by the region judgment means, based on the image information, extracts the graphics data and control data designated by the data storage means; a second graphics data producing means which, when the control data extracted by the data extracting means indicates that the drawing is not completed, produces production of new graphics data according to the image information in the graphics list, and when the control data extracted by the data extracting means indicates that the drawing is already completed, eliminates production of new graphics data; a drawing means which draws the graphics data produced by the respective graphics data producing means on the pixels designated by the data storage means; and a control data providing means which provides data indicating drawing completion for the control data of the pixels drawn by the drawing means among the control data in the data storage means.
An aspect of the present invention is characterized by the fact that the respective means in the above respective graphics drawing devices are formed into a one chip LSI and are mounted on a common substrate.
Further, an aspect of the present invention is characterized by the fact that a three dimensional graphics display device comprises a display device which displays a three dimensional image on a display screen according to the graphics data of the respective pixels drawn by one of the above drawing devices.
An aspect of the present invention is characterized by the fact that, in the course of successively drawing the pixels in the respective graphics only when control data or a flag is stored as information representing that the drawing is not completed in a control data writing region, the drawing is executed according to the image information, and when control data or a flag is stored as information representing that the drawing is completed in the control data writing region, the redrawing is prohibited, so that it is enough only to judge the information of the control data writing region for judging an overlapping of the graphics, with the result that the amount of information needed for judging the overlapping of the graphics can be limited and the capacity of the data storage region storing the graphics data can be reduced.
An aspect of the present invention is characterized by the fact that, in the course of drawing respective graphics based on the graphics list, when a drawing region of a polygon belonging to the graphics list is contained in a drawing region of a polygon belonging to a graphic having a higher order of drawing, the former graphic is deleted from the graphics list and only a drawing for the respective pixel of the graphics judged as not contained is performed, so that only graphics not overlapping others are extracted and a high speed drawing processing is achieved.
Further, an aspect of the present invention is characterized by the fact that, in the course of drawing the respective graphics, it is judged whether or not drawing regions of the respective graphics belong to a drawing region relating to a graphic having a higher order of drawing and drawing for the graphics judged as not belonging is executed according to the image information, such that Z comparison in the drawing processing is eliminated and a high speed drawing processing is achieved.
An aspect of the present invention is characterized by the fact that in order to realize a high speed image processing system through parallel processing and use of a high speed memory access in the system, the processing performance of a CPU is not reduced even when a processor other than the CPU accesses the memory. Namely, in order to permit a plurality of processors to simultaneously access a memory, a bus use bit range for the respective processors is controlled.
Further, an aspect of the present invention is characterized by the fact that, in order for every module to control a memory independently, at least one control line can be controlled separately.
Further, an aspect of the present invention is characterized by the fact that, in order to permit respective memory modules to access different row addresses, a control which permits a row address activating command to be selectively set in a memory is performed.
Further, an aspect of the present invention is characterized by the fact that high quality image processing arithmetic in the image input and output processing is performed through a spacial filtering while making use of multi-valued information, coding and decoding processing arithmetic is performed through table retrieval based on variation point detection and a bit pattern, modern arithmetic in the communication processing is performed through digital filtering while making use of sum of product arithmetic. A one chip processor performing the above processings and constituted by a high speed RISC and an image processing core and a high speed memory are connected via a dedicated bus, and the processings and memory are integrated.
Further, an aspect of the present invention is characterized by the fact that, memories for the respective processings are mapped on a common memory address.
Further, an aspect of the present invention is characterized by the fact that, in order to execute the respective processings in a multi-task manner, a register is provided which dynamically allocates bus occupying time for the respective processings depending on their predetermined processing loads so as not to drop below a minimum bus throughput for guaranteeing a real time operation for the respective processings. The register can be easily modified by software, and the set values can be modified, such as by the processing sequences and the operating modes.
Further, an aspect of the present invention is characterized by the fact that, in order to enhance bus efficiency, a means is provided which predicts a change in the row address and issues in advance an address control command.
Further, an aspect of the present invention is characterized by the fact that, in order to reset effective data in an internal arithmetic register at the time of task switching, a means is provided which returns a read address and executes restarting of a processing.
An aspect of the present invention is characterized by the fact that, through control of the bus bit range by the processor, if no conflicts between bit ranges are caused, simultaneous access can be achieved.
An aspect of the present invention is characterized by the fact that, since the memory bus can be adjusted by the bit range, the CPU and the image processing use a processor which can access the memory in parallel, depending on the operation mode, and the processing can be continued with no overhead for mishits and high speed processing is achieved.