JPH0114608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a device that performs high-speed vector/raster conversion of two-dimensional coordinate data output from a tablet or the like.

[Background of the invention]

FIG. 1 is a diagram showing the principle of a conventional device of this type. The memory 1 stores two-dimensional coordinate data (x, y) output from a tablet or the like. Each bit in the image memory 2 is associated with two-dimensional coordinates (x, y). Vector raster conversion device 3
retrieves the two-dimensional coordinate data from memory 1,
By setting the associated bit in the image memory 2 to 1, a bit pattern corresponding to the two-dimensional coordinate string in the memory 1 is created in the image memory 2.

That is, the conversion circuit 3 sequentially starts from the memory 1,
The coordinate data is taken in and the address of the bit in the image memory 2 corresponding to the coordinate data is calculated.
Next, one word containing the above-mentioned bit in the image memory 2 is fetched, the above-mentioned bit is set to "1", and the one word is written to the original address of the image memory 2.

However, if the image memory 2 has a large capacity,
Since the access speed is low, the conventional method of reading and writing data by accessing the image memory 2 for each coordinate point as described above significantly increases overhead. Therefore, the vector raster conversion process performed by the conversion circuit 3 requires time, and the interval at which coordinate data is retrieved from the memory 1 becomes long.

When inputting image data online, etc., it becomes necessary to store and retrieve coordinate data in the memory 1 in a time-division manner. In this case, the long take-out interval may pose a problem. For example, when inputting by hand from a tablet, the coordinate data is accumulated in memory 1 while one stroke is input, and the coordinate data is retrieved from memory 1 until the next stroke is input, and the coordinate data is stored as a vector. Raster converted. At this time, since the vector raster conversion takes a long time, if the coordinate data extraction interval is long, the extraction of the coordinate data of the previous stroke will not be completed before the next stroke is input. Therefore, the amount of coordinate data stored in the memory 1 increases. Therefore, in order to avoid overflowing the memory 1, it is necessary to impose restrictions on the method of handwriting input to the tablet, such as increasing the time between strokes.

[Purpose of the invention]

The present invention aims to speed up the conversion of coordinates from memory 1 to memory 2 and eliminate the above-mentioned drawbacks.

[Summary of the invention]

FIG. 2 is a principle diagram of a converting device 3' according to the invention. The features of the present invention are as follows. The first feature is that a small-capacity, high-speed memory 40 is provided between memories 1 and 2, point-by-point vector raster conversion is performed on the memory 40, and writing to the memory 2 involves conversion from the memory 40. It is not a simple image conversion. The second feature is that it has a function to set the range of coordinate data (hereinafter referred to as virtual input area) to be continuously vector-raster-converted to the memory 40 as the coordinate data taken out from the memory 1 changes. It is.

[Embodiments of the invention]

Hereinafter, an embodiment of the present invention will be described in more detail with reference to the drawings.

FIG. 3 shows the configuration of an apparatus according to an embodiment of the present invention. 21 is a tablet;
Used in switch stream mode. In switch stream mode, coordinate data is output from the tablet during pen down (the state in which the stylus is pressed down on the input surface), and coordinate data is output from the tablet when the tablet is pen up (the state in which the stylus is separated from the input surface).
During this period, coordinate data is not output.
22 is a calculator. 23 is an image memory;
A utility model application dated June 17, 1995, filed by the same applicant, entitled "Document image data cutting/synthesizing device," for loop transfer processing that performs batch transfer of partial images by one overhead.
Contains DMA control circuitry (not shown). 24
is the output bus of the computer 22, 25 is the input bus, 26
27 is a flag line, and 28 is an interrupt line.

FIG. 4 shows areas within the main memory (not shown) within the computer 22. 9 is time counter 1
0 is an input pointer 11 is an output pointer, 12 is an interpolation start point, 13 is an interpolation end point, 14 is a conversion coordinate point, and 15 is a virtual input area parameter.
16 is the input area, which corresponds to memory 1 in Figure 2, 17
is an output area, which corresponds to the memory 40 in FIG.

[Explanation of operation]

The computer repeats the input state of coordinate data output from the tablet and the coordinate data conversion state.

(1) Coordinate data input state When the computer 22 wants to import data from the tablet 21, it sends a data transfer request to the tablet 21 via the line 26, sets a timer value in the time counter 9, and starts timer operation. do. The tablet 21 is configured to output coordinate data periodically, for example every 5 msec, using a flag sense method, and
After receiving a data transfer request from , when a pen touch is detected, 1 is set in the flag line 27,
And on the bus 24, the touch position coordinates (x, y)
Output. The computer 22 takes in the data on the bus 24 in response to this flag when the timer counter 9 has not timed up. The input coordinate data is stored at the address within the input area 16 indicated by the input pointer 10, and the input pointer is updated by 1 after this storage. Thereafter, the above operations of sending a data transfer request and fetching data from the tablet are repeated. A timer counter 9 is set each time a data transfer request is sent. If the timer counter 9 times up without a flag being input after sending the data transfer request, it is determined that a pen-up has been made and the process moves to the next coordinate conversion operation.

(2) Coordinate data conversion state The computer 22 sequentially reads input coordinate data from the input area 16 and converts the data.
Reading is performed to the address of the input area 16 indicated by the output pointer 11, and after reading, the output pointer is updated by 1.

The data conversion method will be explained below with reference to FIG.

Following the input pointer 10, the coordinate data of the first point is read out from the input area 16, that data is used as a converted coordinate point, stored in the area 14, a virtual input area is set, and vector raster conversion is performed. Next, the converted coordinate point is set as the interpolation start point and stored in area 12. At this time, output pointer 1
Update 1 by 1.

When the second and subsequent points are read, that data is set as the interpolation end point and stored in area 13. Next, based on the interpolation start point of area 12 and the interpolation end point of area 13, interpolation data between these points is sequentially generated, and these are successively transformed coordinate points.
Perform the data processing shown in the figure. Next, the same data processing is performed for the interpolation end point, and finally, the interpolation end point is set as the interpolation start point. Next, the output pointer 11 is updated by 1. Before reading the coordinate data in the input area 16, the output pointer 11 and input pointer 10
are compared, and unless they match (that is, as long as output pointer 11 is smaller than input pointer 10)
A series of operations such as reading, interpolation point calculation, data processing, and updating of the output pointer 11 described above are repeated. If the value of the output pointer 11 becomes equal to the value of the input pointer 10, the input area 16
Assuming that the transfer of all the data in the output area 17 has been completed, the contents in the output area 17 are collectively transferred to the image memory 23, and the computer 22 shifts to the coordinate data input state.

The data processing in FIG. 6 will now be explained.

Check whether the data at the transformation coordinate point is within the virtual input area. If it is within the area, move to , if it is outside the area, move to .

The contents of the output area 17 are transferred all at once to the image memory 23, and a virtual input area is set. Proceed to.

The transformed coordinate points are vector-raster transformed into the output area 17.

The setting of the virtual input area is the following process.

Based on the converted coordinate points, the position of the virtual input area is determined and written in the virtual input area parameter area 15.

The contents in the image memory 23 for the virtual input area are transferred to the output area 17 all at once. Assuming that the converted coordinate point is (x, y), the virtual input area corresponds to a rectangle 30 centered on the point (x, y), as shown in FIG. ₀ , y ₀ ), and the address (X ₀ , Y ₀ ) of the upper left end of the corresponding rectangle 40 (corresponding to the memory 40) on the image memory (see FIG. 8) are defined as follows, respectively. . Here, x ₀ , y ₀
is the bit display coordinate value of the word boundary (for example, 1
If the word is 8 bits, x ₀ is 0, 8, 16, 24
...discrete values), X ₀ and Y ₀ are word display coordinate values.

l...The horizontal length of the virtual input area on the tablet (l = L x W), l is a multiple of W (bits) h...The vertical length of the virtual input area on the tablet (h = H), h is 2 Multiple (bits) W...Number of bits in 1 word x _nax y _nax ...Maximum value of x, y coordinates of tablet (bits) [ ]... Gauss symbol (largest integer less than or equal to the value inside [ ]) All at once At the time of transfer, the processing device 22 transfers initial data (X _L , L, X ₀ , Y,
S, A ₀ ) through the data bus 5.

Here, X _L : Length per line of the image memory (words) L: Length per line of the partial image in the virtual input area (words) X ₀ : X coordinate of the upper left end point of the partial image in the virtual input area (words) ) Y ₀ : 〃 〃 Y 〃 (row) S: X _L × H H: Number of lines of partial image in virtual input area (row) A ₀ : Start address (word) of area 17 of main storage device Vector raster conversion is The following is the processing.

One word containing one bit corresponding to the transformed coordinate point is read from area 17. Letting this address be A, A can be given by the following equation.

A = A ₀ + (L x y' + [x' / W]) [ ] Gaussian symbol where A ₀ : Start address of area 17 L: Horizontal length on screen of virtual input area (word) x' = x -x ₀ : Relative x-coordinate of the converted coordinate point in the virtual area y'=y-y ₀ : 〃〃y-coordinate One bit corresponding to the converted coordinate point is set to 1 and written to the address A indicating the above word.

The bit to be set to 1 here is given by MOD(x'/W).

〔Effect of the invention〕

With this method, the time required to vector-raster transform the coordinate data in the input area 16 and create raster data in the image memory 2 is significantly shortened.

As a result of applying this method to a handwriting input device using a tablet, in the case of normal handwriting, the vector/raster conversion time is no longer longer than the interval between strokes. This has resulted in a significant improvement in the operability of the handwriting input device using a tablet.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional device, Figs. 2 and 3 are block diagrams of an embodiment of the present invention, Fig. 4 is a configuration diagram showing a storage area, and Figs. 5 and 6 are processing according to the present invention. 7 and 8 are explanatory diagrams of the virtual input of the present invention.

Claims (1)

[Claims] 1. an image memory, a means for inputting vector coordinate data, a first memory for storing the vector coordinate data, a means for sequentially reading the vector coordinate data from the first memory, and a means for sequentially reading the vector coordinate data from the first memory; means for setting a raster conversion target area of a predetermined size having reference position coordinates according to the value of the vector coordinate data; means for converting the read vector coordinate data into raster data; A second memory of a predetermined size for temporary storage, and each time a series of raster transformations for vector coordinate data located within the raster transformation target area are completed, the data in the second memory is stored in the image memory. means for collectively transferring the raster conversion target area to an area corresponding to the raster conversion target area, and the raster conversion target area setting means sets a new raster conversion target area each time the data is transferred in bulk. A device for converting two-dimensional coordinate data.