JPH0574871B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a signal processing device used in a digital image information transmission system such as so-called videotext or teletext, which transmits various image information using a telephone line or a wireless line. The present invention relates to an image encoding processing device for handling a set of images as a set of geometric figure areas and converting the image information into geometric command data. [Background technology and its problems] In recent years, with the development of the information society, digital image information transmission systems such as videotex and teletext have been developed and put into practical use as so-called new media for transmitting various image information in various countries. It is progressing. For example, in the UK, a system called PRESTEL is already in practical use, and in Japan, the Captain: Character And Pattern system is already in practical use.
Telephone Access Information Network
System) was developed, and furthermore, France's Teletel, Canada's Telidon,
North American
Presetation Level Protocol) is being put into practical use. By the way, in the above-mentioned Teridon system and NAPLP system, one image is treated as a set of geometrical figure areas and the image information is
The method of expressing and transmitting geometric command data using PDI (Picture Description Instruction) code is different from other methods of expressing image information in correspondence with mosaic picture elements or using character codes.
It is highly regarded for its high efficiency as being extremely efficient. In the above PID code, there are six types of commands for drawing instructions using geometric figures: [POINT], [LINE],
[ARC], [RECTNGLE], [POLYGON],
Commands such as [CONTROL] for controlling the mode of the above-mentioned drawing command by specifying [INCREMENTAL], hue, gradation, etc. are defined.
The above command [POINT] sets the plotting start point or plots the point _P0 at an arbitrary coordinate position within the display screen, as shown in A of FIG. In addition, the above command [LINE] draws a line segment connecting two points P ₁ and P ₂ as shown in B in FIG.
Furthermore, the above command [ARC] draws an arc based on the coordinates of the three points P ₁ , P ₂ , and P ₃ as shown in c in Figure 1, and also draws an arc as shown in the dashed line in the figure. A chord connecting the above two points P ₁ and P ₃ is drawn as shown in FIG. 2, and the inside of the chord is filled in. moreover,
In the above command [RECTNGLE],
As shown in the figure, a rectangular outline is drawn with the two points P ₁ and P ₂ as diagonal vertices, and the inside of the outline is filled in. Furthermore, in the above command [POLYGON], as shown in E in Figure 1,
The outline of the polygon defined by the vertices P ₁ , P ₂ , . . . , P _o is drawn, and the inside of the outline is filled in. Furthermore, in the above command [INCREMENTAL], as shown in F in Figure 1, direction data is obtained when proceeding from vertex P ₀ in any one of the eight directions with an arbitrary unit length.
The outline of a line segment or polygon is drawn using D ₁ , D ₂ , _... , Do, and the inside of the outline is filled in. However, in the digital image information transmission system that uses geometric command data as described above, it is possible to greatly reduce the amount of image information that is actually transmitted, and it is possible to perform highly efficient information transmission. However, there is a problem in that it requires a great deal of effort and time to create the image information to be actually transmitted, that is, the geometric command data representing one image. For example, the work of converting a video signal capturing an image to be transmitted into the above-mentioned geometric command data is as follows.
One possible method is for the operator to input contour information, hue/gradation information, etc. one by one using a tablet while viewing the desired image on a monitor television receiver, and at the same time convert it into geometric command data. It is difficult to accurately represent image information, and it requires a great deal of effort and time to input various information. [Object of the Invention] Therefore, in view of the above-mentioned problems, the present invention has been made to
When one image is handled as a set of geometric figure areas and the image information is expressed and transmitted as geometric command data, it is possible to automate the process of converting the image information into geometric command data. An object of the present invention is to provide an image encoding processing device that automatically forms each geometrical command data for each geometrical region of an image to be transmitted, accurately and efficiently in a short time. [Summary of the Invention] In order to achieve the above-mentioned object, an image encoding processing device according to the present invention includes an image storage means for storing input image data, and an image storage means represented by the input image data stored in the image storage means. Regarding an image, an image area determining means determines an image area indicated by substantially the same image data, a memory stores direction data indicating continuous directions of image boundaries, and image data of a center pixel and surrounding pixels is determined. It consists of a comparison circuit that performs a comparison with the image data, and a boundary detection circuit that detects that the comparison result by this comparison circuit is inconsistent and reads and outputs the direction data from the memory, and the direction data is stored in the image storage means. With respect to the input image data, each vertex of the corresponding geometric figure is obtained by detecting the boundary information of the image area and the change point of the direction data based on the detection result by the boundary detection circuit, and the image area determining means and an image area detection means for detecting each image area determined by the image area detection means, and for the input image data stored in the image storage means, sequentially detecting each pixel of the detected image area detected by the image area detection means from a specific position. Search to determine an unprocessed image area for encoding processing, trace a boundary line based on the above-mentioned direction data corresponding to the unprocessed image area, and determine the vertices and boundary line of a geometric figure drawn by the boundary line. A data table indicating the length of is created, and for the unprocessed image area shown in the data table, a pair of vertices of the detected image area connected by a line segment passing only through the unprocessed image area outside the image area. , and delete the vertices existing between these pairs of vertices and change the data table to the data of the encoded image area shown, and create the encoded image area from which the vertices existing between the pairs of vertices have been deleted. encoding processing means for generating geometric command data representing the detected image area detected by the image area detecting means as a geometric figure based on data of a data table storing data of vertices and boundary lines; The apparatus is characterized in that it comprises a control means for controlling the operation of each means, and each image area indicated by the input image data is converted into geometric command data by the encoding processing means and output. [Embodiment] Hereinafter, an embodiment of the image encoding processing device according to the present invention will be described in detail with reference to the drawings. The embodiment shown in FIGS. 2 to 30 is an example in which the present invention is applied to an input data processing device in a digital image information transmission system using the Teridon method. Obtained by capturing an image with a camera
When an RGB color signal or a color television signal of a standard television system (for example, NTSC) is input, one frame's worth of color image shown by this input is treated as a set of geometric figure areas, and a geometric figure representing the color image is The microcomputer 100 generates scientific command data and outputs it through a data path. In the block diagram of FIG. 2 showing the overall configuration of the apparatus of this embodiment, for example, an NTSC color television signal is input through the first signal input terminal 1.
The RGB color signal is supplied to an NTSC/RGB converter 5 and a sync separation circuit 6, and the RGB color signal is supplied to an input selection circuit 10 via a second signal input terminal 2. The input selection circuit 10 receives an RGB color signal converted from the color television signal supplied from the first signal input terminal 1 via the NTSC/RGB converter 5, or an RGB color signal supplied from the second signal input terminal 2. Select one of the RGB color signals, and convert one RGB color signal to analog/digital (A/D).
It is supplied to the conversion converter 20. Further, the synchronization separation circuit 6 separates the synchronization signal in the color television signal supplied from the first signal input terminal 1 and supplies the synchronization signal to the synchronization switching circuit 15 . The above synchronous switching circuit 15
is supplied to the second signal input terminal 2.
A synchronization signal corresponding to the RGB color signal is supplied from the third signal input terminal 3, and performs a selection operation in conjunction with the input selection circuit 10 to select the A/D.
A synchronization signal corresponding to the RGB color signals supplied to the converter 20 is supplied to the address data generation block 30. This address data generation block 30
consists of a PLL oscillator 31 and a counter circuit 32, and forms address data synchronized with the synchronization signal by counting the oscillation output pulses of the PLL oscillator 31 with the counter circuit 32,
This address data is supplied to the address selection circuit 35. The address selection circuit 35 is connected to the computer 1
The address data supplied via the address bus 00 and the address data supplied from the address data generation block 30 are selected and sent to the first to fourth frame memories 41, 42, 43, 4.
4. Supply the above address data to the cursor memory 45 and character generator 46. In addition, each of the frame memories 41, 42, 43, 4
4. Various data are exchanged between the cursor memory 45 and the character generator 46 through a data path of the computer 100. The first frame memory 41 is a memory for storing original image data, and the A/D converter 20 digitizes the RGB color signal, and the input color image data is stored at the address from the address data generation block 30. based on data
Written for each RGB color. The input color image data stored in this first frame memory 41 can be read out at any time and converted into analog RGB data by a digital/analog (D/A) converter 61.
The signal is converted into a color signal and supplied to the first RGB monitor device 81 via the first output selection circuit 71 so that the original color image can be monitored. Further, second to fourth frame memories 42,
43 and 44 are used as general-purpose memories for various data processing such as color processing and redundant data reduction processing for the original image data stored in the first frame memory 41, and are used to store various images in various processing processes described later. Data is written/read through the data path. The processed image data stored in the second frame memory 42 is converted into color data in the color table memory 51 and converted into analog data via the D/A converter 62.
The RGB color signals are returned to the first and second output selection circuits 71 and 72 and are supplied to the first and second output selection circuits 71 and 72, allowing the data-processed color image to be monitored by the first or second RGB monitor devices 81 and 82. ing. Further, the processed image data stored in the third frame memory 43 is converted into color data in a color table memory 52 and
The signal is returned to analog RGB color signal via the A converter 63 and outputted from the second output selection circuit 72 to the second output signal.
The data is supplied to the RGB monitor device 82, so that the data-processed color image can be monitored. Furthermore, the fourth frame memory 44
The original image data stored in the first frame memory 41 is converted back to an analog RGB color signal by the D/A converter 61, converted to a luminance (Y) signal by the RGB/Y converter 68, and further converted into A /
The black and white image data of the original image obtained by digitizing it via the D converter 69 is written. After performing redundant data reduction processing on this black and white image data, the black and white image data is returned to analog RGB color signals via the color table memory 53 and the D/A converter 64 and is supplied to the signal synthesis circuit 70. It is becoming more and more common. The signal synthesis circuit 70 is supplied with a cursor display signal from the cursor memory 45, and character data for displaying various system control commands from the character generation 46 is stored in an analog RGB color table memory 54.
An image based on image data converted into a color signal and stored in the fourth frame memory 44, a cursor image based on a cursor display signal from the cursor memory 45, and a cursor image from the character generation 46. It synthesizes and outputs RGB color signals that are superimposed with an image based on character data. The image based on the RGB color signals obtained by this signal synthesis circuit 70 can be monitored by the second RGB monitor device 82, and
The color signal is converted into a luminance Y signal by an RGB/Y converter 80 and can be monitored by a monochrome monitor device 83. Furthermore, in this embodiment, the microcomputer 100 functions as a controller that controls the operation of the entire device, and its data bus and address bus include an auxiliary memory 90 such as ROM and RAM, a floppy disk controller 91, and a floppy disk controller 91. An input/output interface circuit 93, a high-speed arithmetic processing circuit 200, and the like are connected.
Note that the input/output interface circuit 93 includes:
A tablet 94 and its monitor device 95 are connected for inputting various data during manual editing processing. The apparatus of this embodiment performs image processing according to the procedure shown in the flowchart of FIG. The data is converted into scientific command data and output via the data bus. That is, the input color image data is first
The image data is written into the frame memory 41 and stored as original image data. Here, the input color image data can be selected from either the NTSC color television signal or the RGB color signal by switching the input selection circuit 10 and the synchronization selection circuit 15. Further, the original image data stored in the first frame memory 41 is RGB/
The Y converter 68 converts the data into black and white image data, which is also stored in the fourth frame memory 44 . Next, the first and fourth frame memories 4
Based on the image data stored in 1 and 44, color processing is performed on the input color image data, redundant data reduction processing is performed, and finally geometric command data is obtained without losing the characteristics of the original image. automatically generates image data suitable for conversion to After performing each of the above processes, encoding processing for converting image data into geometric command data is automatically performed. Note that when the original image is artificially modified and transmitted, manual editing processing is performed before the encoding processing to the geometric command data. In the above color processing, the first frame memory 4
FIG. 4 shows a process of automatically selecting the top n most frequently occurring colors in the original color image indicated by the input color image data stored in 1 and assigning one of the above n colors to each pixel. Follow the steps in the flowchart. In this color processing, the high-speed arithmetic processing circuit 200 first creates a histogram of each color data for the input color image data stored in the first frame memory 41, and the top n color data of this histogram is Select. Next, for each image area shown with the same brightness of the black and white image represented by the black and white image data stored in the fourth frame memory 44, the n colors closest to the color of the original color image are selected. Colors are assigned to form color table data in order of brightness, and the color table data is corrected so that the deviation is minimized for each pixel. The color table data thus formed by the high-speed arithmetic processing circuit 200 is stored in each color table memory 51, 52, 53.
is memorized. Furthermore, the color-processed image data in which the n colors are assigned to each of the image areas is written into the second frame memory 42 . The color image subjected to the color processing can be created by reading each color data from the first color table memory 41 using the image data stored in the second frame memory 42 as address data. RGB monitor device 81,
Monitored at 82. In addition, in the redundant data reduction process, noise cancel processing, halftone removal processing, small area deletion processing, etc. are performed on each image data stored in the second and fourth frame memories 42 and 44. , redundant data unnecessary for the encoding process to the next geometric command data is removed to reduce the amount of information. This reduction process is carried out by the high-speed arithmetic processing device 200.
It will be held at For example, as shown in Figure 5, 3
×3 9 pixels [A] [B] [C] [D] [E]
Regarding [F] [G] [H] [I], 4 neighboring pixels [B] [D] [F] [H] to the center pixel [E]
When three or more of the data are the same,
The noise canceling process is performed by replacing the data of the center pixel [E] with this value. Also, for the center pixel [E], each pixel column [A・E・I], [B・E・H], [C・E・
If two or more of [G] and [D・E・F] are monotonically increasing or decreasing, the center pixel [E] is set to the nearest value among the 8 neighbors, with the center pixel [E] as a halftone pixel. ] By replacing the data in
The above halftone removal process is performed. Further, the small area deletion process is performed by merging small areas with an area smaller than a specified area to adjacent areas. In this way, the high-speed arithmetic processing circuit 2
The image data subjected to redundant data removal processing at step 00 is read into the third frame memory 43 and monitored by the second RGB monitor device 82 via the second color table memory 52. Furthermore, in the above-mentioned manual editing process, the color image represented by the image data obtained by automatically performing the above-mentioned color processing and reduction processing, artificially adds or deletes new motifs, corrects colors, etc. Perform the process to add. This manual editing process is performed by the black and white monitor device 8 that monitors the image based on the black and white image data stored in the fourth frame memory 44.
This is done using a transparent tablet 94 placed on the screen of No. 3. On the screen of the black and white monitor device 83, character information images for displaying various control commands necessary for manual editing are displayed on the character generator 46.
and the above tablet 9
A cursor image for displaying the position information generated from 4 is provided in the cursor memory 45, and when the operator corrects the image using the pen attached to the tablet 94, the cursor image is displayed in real time. The results will be displayed. Then, in the encoding process to the geometric command data, one part of each image area is
Command data expressed by geometric commands one by one is formed according to the procedure shown in the sixth flowchart. Here, a geometric image region as shown in FIG.
The above encoding process will be explained by taking as an example a case where the original images indicated by AR ₁ , AR ₂ , AR ₃ , AR ₄ , and AR ₅ are converted into geometric command data. In this encoding process, for an image represented by color image data that has been processed in various ways as described above, the image data is searched, for example, from the lower left of the image to detect an unprocessed image area of the encoding process, and this unprocessed image area is detected. A data table is created that shows the vertices of a geometric figure drawn by the boundary line and the length of the boundary line by tracing the boundary line for the processing image area. For the original image shown in FIG. 7 above, first, the first image area AR ₁ as shown in FIG. 8 is detected, and each vertex P ₁₀ ,
P ₁₁ , ..., P ₁₉ and the length of the boundary line l ₀₁ , l ₁₂ , ...
Create a data table showing ..., l ₈₉ , l ₉₀ . Next, for the unprocessed image area shown in the data table above, detect pairs of vertices that can be connected by a line segment that passes only through other unprocessed image areas without passing through the own area and the encoded area. , the data table is changed to the data of the encoded image area shown by deleting the vertices existing between these pairs of vertices. That is, for the first image area AR ₁ , as shown in FIG. ₈ , each of _the vertices _{P 13 ,} P ₁₃ ,
Each vertex P ₁₀ , P ₁₁ , P _{16 ,} P _{18 , indicating the encoded image area AR 1 ′ as shown in FIG. 9A with P 14 and P 17 deleted ,}
Change the data table to data for P ₁₉ and boundaries l ₀₁ , l ₁₆ , l ₆₈ , l ₈₉ , and l ₉₀ . Note that the above vertices P ₁₂ ,
The P ₁₅ pairs have been deleted because by connecting them they are no longer vertices of the geometric figure. Then, the above-mentioned PDI code, for example [POLYGON], is formed based on the data table of the encoded image area _AR'1 from which vertices existing between a pair of vertices have been deleted as described above. Furthermore, the encoded image area encoded with the above geometric command data
Command data [CONTROL] corresponding to the color determined by the color processing described above is given to AR′ ₁ to designate the color of the area, and the encoding process for the first image area AR ₁ is completed. When the encoding process for the first image area AR ₁ is completed, return to the unprocessed image area detection operation described above, and then perform the encoding process for the second image area AR ₂ in the same procedure, Thereafter, the encoding process is sequentially performed on the third, fourth, and fifth image areas AR ₃ , AR ₄ , and AR ₅ , and the encoding process ends when there are no unprocessed image areas. . Note that in FIGS. 9A to 9E, each image area AR ₁ ,
Each encoded image area AR' ₁ , AR' ₂ , AR _{' 3} , AR _{' 4} , AR _' 5 for AR ₂ , AR ₃ , AR ₄ , AR ₅ is shown. Here, when performing encoding processing that includes color specification for _each image region, for example, as _shown in _FIG .
When converting AR into command data using a PDI code, the image area AR hue is specified using a combination of a texture pattern TXP and the hue of the texture pattern TXP, and first each vertex P ₀ , P ₁ , . . . , each position coordinate of P ₄ [X ₀ , Y ₀ ],
Code the back color with [X ₁ , Y ₁ ], ..., [X ₄ , Y ₄ ], then create the texture pattern.
Specify TXP and its color and each of the above position coordinates [X ₀ , Y ₀ ], [X ₁ , Y ₁ ], ..., [X ₄ , Y ₄ ]
By coding again, the coding for the image area AR is completed. As the above texture pattern TXP, for example, the 11th
As shown in the figure, three types of patterns TXP ₁ , TXP ₂ ,
By selectively designating TXP ₃ and selectively designating its forecolor from two colors, black and white, it is possible to designate five gradations of color for the image area AR, as shown in FIG. In other words, if the texture pattern TXP between two colors is m _P types, and the colors are n _P types, then N _P = n _P + n _P (n _P −1)/2×m _P , so N _P types. The color of can be expressed in a pseudo manner. Here, a specific example of color designation for each image area in this embodiment will be explained. In order to simplify the explanation, the input color image data is R, G,
Assume that each hue of B has three levels, and the hue of the original image is represented by color data of 3 ³ =27 colors. For example, as shown in FIG. 13, the hue C ₀ where each level of R, G, and B is indicated by [0, 1, 2]
In order to synthesize R, G, B with 2 levels, that is, 2 ³ = 8 colors, the levels of R, G, B should be [0, 2,
Hue C _B and [0,0,2] shown by broken lines in the figure of [2]
It is sufficient to mix the hue C _F shown by the dashed line in the figure at a ratio of 1:1. In other words, the back color
C _B [0,2,2], color C _F [0,0,
2] and use a checkered texture pattern. Therefore, color data D _C [R, G, B] of input color image data indicating each hue of the original image
By reading out texture data as shown in FIG. 14 from the texture memory using as a read address, it is possible to specify 27 colors. Note that the texture data consists of front color specification data C _DF [R, G, B], back color specification data D _CB [R, G, B], and texture specification data D _TX , and D _TX = 0 means that only the front color is used. D _TX =1 indicates that a checkered texture pattern is specified. Furthermore, the above-mentioned determination of each image area may be performed by using a boundary detection circuit having a configuration as shown in FIG. 15, for example, which is implemented in the high-speed arithmetic processing circuit 200. In FIG. 15, pixel data for one frame of n bits per pixel of an image to be processed by this device is written in advance in an image memory 210. The image memory 210 consists of randomly accessible RAM of any size. Further, the address line of the image memory 210 contains offset data read from the offset ROM 202 addressed by the count output of the timing counter 201 that counts clock pulses supplied from the microcomputer 100, and offset data from the microcomputer 100. The supplied center address data is added to the adder 203.
The address data added at is supplied.
Furthermore, the timing counter 201 is connected to the write/read control line of the image memory 210.
An R/ signal obtained by decoding the output of the timing gate 204 at the timing gate 204 is supplied. Here, the timing counter 201 counts the clock pulses and outputs a decimal count as shown in the time chart of FIG.

[0], [1],
...,

[9] is supplied to the offset ROM 202 and timing gate 204. The offset ROM 202 also contains the counting output.

[0],
[1],...,

Offset data [], [], [], ..., [] to the address specified in [9]
，
[], [] are written. The above offset data [], [], [], ..., [], []
，
[ ] is 9 pixels in 3 rows and 3 columns shown in Figure 17,
It corresponds to ,...,,. Further, the timing gate 204 outputs the count output.

[0],
[1],...,

By decoding [9],
Count output

During the period from [0] to count output [8], the logic “1” indicates the writing period _TR , and the count output

[9]
During the period, the R/ signal indicating the read period _TWR is formed at logic "0". Then, the adder 2
03, by adding the center address data and the offset data, the pixel to be detected specified by the center address data is set as the center pixel, and its 8 neighboring pixels,...
..., and each pixel data of the above center pixel is 1
Address data to be specified sequentially during a cycle period is formed. Image data sequentially read out from the image memory 210 is supplied to an n-bit nine-stage shift register 220 through a data line. The shift register 220 sequentially transfers the image data in accordance with the clock pulse, and temporarily stores the image data of the nine pixels in the three rows and three columns, . . . . Each image data temporarily stored in the shift register 220 is supplied to a data comparison circuit 230, where the image data of the center pixel, that is, the detection target pixel, and each image data of eight neighboring pixels, . . . are compared. Ru. The data comparison circuit 230
are eight comparators 231, 2 of n bits each.
32, . The direction ROM 240 is pre-written with direction data indicating the direction in which the image boundaries are continuous.
This direction data is read out via the latch circuit 250 as a boundary detection output. The latch circuit 250 includes the timing gate 2
The R/ signal is supplied from 04 as a latch clock, and at the falling edge of this R/ signal, that is, at the timing when all the image data of each pixel,..., is temporarily stored in the shift register 220, the above direction is set. The data is now latched. Further, the boundary detection output, ie, direction data, outputted via this latch circuit 250 is supplied to the direction ROM 240 as address data. Here, the center pixel and its 8 neighboring pixels,
When the center pixel is the detection target pixel, the direction in which the boundaries of _the image shown by .
It can be uniquely determined by D ₁ [〓], D ₂ [↑], ..., D ₇ [〓]. Furthermore, if we want to detect that the boundary of the image is continuous with respect to the center pixel, for example, in the counterclockwise direction for 8 neighboring pixels, the above-mentioned direction data D ₀ , D ₁ ,
..., D ₇ is determined by the image data of the other four pixels, provided that the image data of each pixel, ..., is in the state shown in Figure 18. . In other words, each direction data
Four pieces of pixel data are uniquely determined for D ₀ , D ₁ , . . . , D ₇ . Note that in FIG. 18, a circle mark indicates that the image data match, and a cross mark indicates that the image data do not match. Then, if continuous boundaries of the image are sequentially tracked in a counterclockwise direction, the direction data obtained in the previous detection operation and the current detection target pixel, that is, 8 neighboring pixels to the center pixel,
, . . . , direction data can be uniquely determined from the match/mismatch state of each pixel data. That is, first, to determine the first detection target pixel of the image area for which boundary detection is to be performed, image data is searched from the bottom left of the image, for example, and as shown in FIG. , , , are all in a mismatched state with respect to the center pixel, and it is sufficient to detect the detection target pixel. The direction detection output for this first detection target pixel is one of three types: D ₀ [→], D ₁ [〓], D ₂ [↑], and the content of the image data △ of each pixel, , can be uniquely determined as shown in FIG. In addition, in a state where direction detection is performed by tracking the boundary, the match/mismatch state of 3 of the 8 neighboring pixels has already been determined with respect to the center pixel determined by the previous detection operation. With the image data Δ of the other five pixels, the direction detection output is uniquely determined according to the position of the previous detection target pixel, as shown in FIGS. 20A to 20H. Note that in FIG. 20, the mark ◎ indicates the pixel to be detected during the previous detection operation. The direction ROM 240 contains direction data that is uniquely determined by the coincidence detection data of each pixel data of 8 neighboring pixels to the center pixel, and the previous boundary detection output, that is, direction data.
D ₀ , D ₁ , ..., D ₇ are written in advance, and the above coincidence detection output data and direction data are read out and the above direction data D ₀ , D ₁ , ..., D ₇ are used as boundary detection outputs. Read out. As in this embodiment, if the boundary detection output is obtained by reading the direction data written in advance in the direction ROM 240 using the output data of the comparator circuit 230, the conventional 16-bit microcomputer can perform the detection in several tens of microseconds. Image boundary detection processing, which previously required approximately 300 ms of processing time, can now be performed in an extremely short time of approximately 1 to 3 .mu.s. In this boundary detection circuit, the detection level data is input to the data line via the 3-state interface circuit 205, and the R/ signal is at logic "0", that is, the 3-state signal is set to logic "0" during the write period _TWR .
By controlling the state interface circuit 205 to an enabled state, the boundary detection level can be changed arbitrarily. Also, the direction
All bits of direction data read from the ROM 204 via the latch circuit 250 are transferred to the direction ROM 2.
As shown in FIG. 21, only the most significant bit data [B ₂ ] of the direction data D read out from the direction ROM 240A is sent to the direction ROM 240A via the latch circuit 250A. Alternatively, the address data may be returned to the address data. In other words, when sequentially detecting continuous directions of image boundaries as described above, due to the boundary of the previous detection operation, the coincidence/mismatching state of three of the eight neighboring pixels to the current center pixel is This has already been determined, and the output data of the comparator circuit 230 for 3 bits is also determined as shown in Table 1.

〔Effect of the invention〕

As is clear from the description of the embodiments above, the image encoding processing device according to the present invention treats each image area of the original image indicated by the input image data stored in the image storage means as a set of geometric figures. When handling and sequentially encoding geometric command data, the image area is encoded by removing vertices between pairs of vertices that can be connected by a line segment that passes only through the unprocessed image area. Encoding processing can be performed efficiently by reducing the number of vertices and perimeter of a region. Therefore, according to the present invention:
It becomes possible to automatically form each geometrical command data for each image region from input image data accurately and in a short time, and the intended purpose can be fully achieved.

[Brief explanation of the drawing]

A, B, C, D, E, and F in FIG. 1 are schematic diagrams each schematically showing graphic processing using the PDI code. FIG. 2 is a block diagram showing an embodiment of an image encoding processing apparatus according to the present invention. FIG. 3 is a flow chart showing the image processing procedure in this embodiment, and FIG. 4 is a flow chart showing the color processing procedure. FIG. 5 is a schematic diagram showing an arrangement of processing target pixels for explaining the operation of the information amount reduction processing in the above embodiment. FIG. 6 is a flowchart showing the procedure of code processing in the above embodiment. 7 to 9 are schematic diagrams for explaining the principle of the above encoding process,
FIG. 7 shows each image area of the original image, FIG. 8 shows the unprocessed image area first detected in the above encoding process, and FIGS. This shows an image area to be encoded. 10 to 14 are schematic diagrams for explaining the color specification process in the encoding process of the above embodiment, FIG. 10 shows the image area to be processed, and FIG. 11 shows each of the texture patterns. As an example, FIG. 12 shows a state in which the image area shown in FIG. 10 is specified with a color using each texture pattern shown in FIG.
The figure shows the operating principle of color specification when converting 3-level color data to 2-level color data. Figure 14 shows the texture used when specifying 27 colors according to the above-mentioned color specification operating principle. An example of data is shown. 15 to 22 show an example of the image boundary detection circuit in the above embodiment, FIG. 15 is a block diagram showing the configuration of the boundary detection circuit, and FIG. 16 shows the operation of the above detection circuit. FIG. 17 is a schematic diagram showing the arrangement of each pixel to be detected, and FIG. 18 is a time chart showing the direction in which the image boundary continues with respect to the detection target pixel and the image of each pixel. FIG. 19 is a schematic diagram showing the operation principle of determining the detection direction during the initial boundary detection operation, and FIGS. 20A to 20H are schematic diagrams showing the direction in which the boundaries are continuous. FIG. 21 is a block diagram showing a modification of the boundary detection circuit shown in FIG. 15 above. , FIG. 22A, and FIG. 22B are respective schematic diagrams showing direction data written in advance in the direction ROM in the above modification. 23 to 29 are schematic diagrams for explaining the operation of forming a data table for encoding processing based on the direction data obtained by the boundary detection circuit in the above embodiment, and FIG. A indicates the boundary line of the image area detected by the boundary detection circuit, and the 23rd
FIG. 24 shows another example of the boundary line detected by the boundary detection circuit, and FIG. 25A shows the data table for the boundary line of the image area shown in FIG. 23A. 24 shows the vertices necessary to encode the boundary line, FIG. 25B shows its data table, and FIG. 26 shows still another example of the above boundary line, and FIG. 27A and 27th
B shows the vertices and their data table necessary to encode the boundary line shown in FIG. 26 above,
Furthermore, FIG. 28 shows yet another example of the boundary line, and FIGS. 29A and 29B show vertices and their data tables necessary to encode the boundary line shown in FIG. 28. It shows. Third
0A to 0E are schematic diagrams for explaining the procedure for reproducing the original image based on the geometric command data obtained by encoding the original image shown in FIG. 7 in the above embodiment. 41, 42, 43, 44...frame memory,
51, 52, 53...Color table memory, 9
0... Auxiliary memory, 100... Microcomputer, 200... High speed arithmetic processing circuit, 210...
Image memory, 220...Shift register, 230
...Data comparison circuit, 240, 240A...Direction
ROM, 250, 250A...Latch circuit.

Claims (1)

[Claims] 1. An image storage means for storing input image data; and an image region for determining an image region represented by substantially the same image data for an image represented by the input image data stored in the image storage means. a determining means; a memory for storing direction data indicating a continuous direction of image boundaries; a comparison circuit for comparing image data of a center pixel with image data of surrounding pixels; and a comparison result of the comparison circuit. a boundary detection circuit that detects a mismatch and reads and outputs direction data from the memory; image area detection means for detecting each image area determined by the image area determination means by obtaining each vertex of a corresponding geometric figure by detecting a change point in the boundary information and the direction data; With respect to the input image data stored in the storage means, each pixel of the detected image area detected by the image area detection means is sequentially searched from a specific position to determine an unprocessed image area for encoding processing,
Trace the boundary line based on the above-mentioned direction data corresponding to the unprocessed image area, create a data table showing the vertices of the geometric figure drawn by the boundary line and the length of the boundary line, and write it in the data table. For the unprocessed image area indicated by , detect pairs of vertices in the detected image area that are connected by line segments that pass only through the unprocessed image area outside the image area, and delete vertices existing between these pairs of vertices. The above data table is changed to the data of the encoded image area indicated by an encoding processing means for generating geometric command data representing the detected image area detected by the image area detecting means as a geometric figure based on the above-mentioned input; and a control means for controlling the operation of each of the above-mentioned means; An image encoding processing device characterized in that each image region indicated by image data is sequentially converted into geometric command data by the encoding processing means and outputted.