JPS63254855A - Scanning distortion correcting system - Google Patents

Abstract

PURPOSE:To calculate a memory address with high accuracy and at high speed by counting an address corresponding to respective picture elements from a position signal by a hand scanner equipped with a position corresponding to both edges of a line sensor. CONSTITUTION:With a hand scanner 2 equipped with a pick-up coil 2-2 at the position corresponding to both edges of a line sensor 2-1, an image on a tablet 1 is read and a center P1 of the picture element corresponds to a lattice point of the nearest tablet 1. Based on coordinates (x1, y1) and (x2, y2) of the coil 2-2, an address calculating circuit 3-1 calculates coordinates (e1+ x, e2+ y) of a central point P2 in accordance with errors e1 and e2 of a moving quantity x, y, a central point P1 and a point A based on a formula, a calculating result exceeds the P/2 of a pitch P=1 of the tablet 1, and then, a next lattice point is corresponded and in the same way, the coordinates of a central point P3 are determined. By the same repeating operation, for the address corresponding to respective picture elements, a memory address is determined with a high accuracy and at a high speed even when the scanner 2 is placed slantingly. In the formula, (n): the number of picture elements of sensor.

Description

[Detailed Description of the Invention] rI Already Required] This invention calculates the memory address for storing the read image based on the inclination of the hand scanner when inputting an image to an image processing device using a hand scanner. In order to facilitate this, the hand scanner is provided with an address calculation circuit that calculates an address corresponding to each pixel from the position coordinates of both ends of the line sensor built into the hand scanner and the number of pixels of the line sensor.

[Industrial application field]

The present invention relates to a scanning distortion correction method, and more particularly to a scanning distortion correction method for a hand scanner when inputting an image to an image processing apparatus using a hand scanner and a tablet.

Image processing devices are widely used in the information field. These image processing devices range from large ones to those that create documents using workstations and word processors, for example. An image input device is sometimes used to input figures into this image processing device, but hand scanners are used for inputting figures that do not require high resolution and are small in size, such as images to be included in documents. A small one like this is sufficient.

This hand scanner has the advantage of being small, easy to operate, and allowing you to input images immediately when you want to input them. Therefore, hand scanners are widely used in word processors and the like. However, this hand scanner has the disadvantage that since the image is scanned manually, scanning fluctuation of the hand scanner occurs during scanning, causing distortion in the input image.

Therefore, in order to correct this scanning distortion, a method is maintained in which a tablet is used to accurately determine the input position of the image. However, with this method, it is difficult to determine the address of the memory that stores data from the line sensor because the mounting direction of the line sensor of the hand scanner and the direction of the coordinate axis of the tablet are not necessarily parallel. Therefore, there is a need for a scanning distortion correction method that can quickly correspond between image data and memory addresses.

[Prior Art] FIG. 6 is a block diagram showing a conventional hand scanner. A rotatable roller 20-1 is provided on the bottom surface of the hand scanner that contacts the image, and a movement amount detection circuit 20-5 detects a predetermined movement amount from the amount of rotation of this roller 20-1, and determines the timing. The signal is input to the generating circuit 20-6. The timing generation circuit 20-6 operates the sensor drive circuit 20-4 which outputs a permission signal that permits output of the image data stored in the line sensor 2-1. Therefore,
When the hand scanner moves a predetermined distance, the line sensor 2-1 transfers image data to the preamplifier 20-2 and the output amplifier 2.
Output via 0-3.

FIG. 7 is a block diagram showing a conventional hand scanner using a doublet. A hand scanner 20 mounted on the doublet 1 is provided with a pickup coil 2-2 at a position corresponding to one end of the line sensor 2-1. The position of the hand scanner 20 is this pickup coil 2-
Detected by 2.

This line sensor 2-1 and pickup coil 2-2
is connected to, for example, a word processor 30.

In the word processor 30, image data of each pixel of the line sensor 2-1 is temporarily held in a line buffer 30-1. On the other hand, the XY coordinate detection circuit 30-2 outputs the X and Y values of the XY coordinates from the output of the pick amplifier coil 2-2. If the hand scanner 20 is shifted in the Y-axis direction and partially moved diagonally, the XY coordinate detection circuit 30-2 inputs the change in Y value to the shift circuit 30-3. The shift circuit 30-3 performs correction by shifting the data in the line buffer 30-1 by the change in Y. Memory address instruction section 30-
The shift circuit 30-3 described above is placed at the address shown in 4-7.
The output data is stored in the memory 30-5.

[Problem that the invention seeks to solve]

The former method, which uses a conventional hand scanner, detects the moving distance by the rotation of the roller, so if the roller slips, it becomes inaccurate and the axial direction of the roller
That is, since no processing is performed in the Y-axis direction, if the roller moves obliquely, distortion will occur in the obtained image. Furthermore, even in the latter method using a tablet, there is a problem in that the memory address cannot be calculated unless the Y-axis of the coordinates of the tablet and the line sensor are parallel.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional situation, it is an object of the present invention to provide a scanning distortion correction method that can calculate memory addresses quickly and with high efficiency.

[Means for solving problems]

In this invention, as shown in FIG. 1, pickup coils 2-2 are provided at positions corresponding to both ends of a line sensor 2-1 of a hand scanner 2. This hand scanner 2 scans the tablet 1. The image data held in the line sensor 2-1 is sent to the memory 3-2 via the control circuit 3-3.
will be forwarded to.

An address calculation circuit 3-1 for calculating a memory address from this transferred data is provided in the image processing device, for example, the word processor 3.

[Effect]

The operation of the address calculation circuit 3-1 of the present invention will be explained with reference to FIG. The centers p, . . . p2 of each pixel of the line sensor 2-1, . Assuming that the error between the center P1 and the grid point A is el, e2, the coordinates to be associated with the center P2 are the line sensor 2-
It shifts by one pixel of 1 and moves by ΔX and Δy, which will be described later.

These ΔX and Δy are the position coordinates of the pickup coil 2-2 provided at both ends of the line sensor 2-1, respectively (
X2. y2), (X+,)'+), and line sensor 2
When the number of pixels of -1 is set to n, the following equation is obtained.

Δx=(x2-Xl)/n Δy=(y2-)'+)/n Therefore, the coordinates of center P2 are el + ΔX.

e, this becomes Δy.

If 1 pitch p = 1 of tablet 1, (el + Δ
When X) exceeds p/2, this coordinate becomes the next coordinate (x+
1), and the error is (el 1). Similarly (e
2 +Δy) exceeds p/2, the next coordinate (y+
1), and the error is (e2-1). In this way, by sequentially and repeatedly calculating the centers P, . . . P4, it is possible to associate all pixels.

〔Example〕

FIG. 2 is a schematic diagram of an embodiment of the scanning distortion correction method of the present invention. The hand scanner 2 has a pickup coil 2-2 at a position corresponding to both ends of the light-receiving surface of the line sensor 2-1 that receives reflected light from the image and in contact with the tablet 1 surface.
There are two. The lamp 2-6 illuminates the pixels on the tablet 1. The reflected light from the pixel is separated into spectra by a half mirror 2-3, and the minus spectra reaches a window 2-4. Therefore, the operator can check the image through the window.

Other spectral lights pass through a lens 2-5 that condenses light and reach the line sensor 2-1. The image data photoelectrically converted by the line sensor 2-1 and the position data detected by the pick amplifier coil 2-2 are input to an image processing device, for example, a word processor 3.

The word processor 3 includes a control circuit 3-3 that controls the word processor 3, and a memory 3-2 that stores pixel data.
and an address calculation circuit 3-1 that calculates the address of the memory 3-2 where pixel data is to be stored.

The operation of the address calculation circuit 3-1 will be explained with reference to FIG. Center of each pixel of line sensor 2-1 P l +P2
... P is the nearest grid point of the tablet 1, for example, the center P1 is associated with the grid point A. This center P1 and lattice point A
Assuming that the error from the center P2 is el+02,
The coordinates to be associated are shifted by one pixel of the line sensor 2-1 and moved by ΔX and Δy, which will be described later.

These ΔX and Δy are determined by assuming that the position coordinates of the pickup coil 2-2 provided at positions corresponding to both ends of the line sensor 2-1 are (X2.3'2) and (X++y+), respectively.
If the number of pixels of the line sensor 2-1 is n, the following equation is obtained.

Δx= (X2 xl ) /nΔ)'=
(y2)'l)/n Therefore, the coordinates of center P2 are e1+ΔX.

It becomes e2 + Δy.

If the l pitch of [tablet] is p・1, then (e+ +
If ΔX) exceeds 1/2, that is, half a pinch, this coordinate becomes (X+1) of the next coordinate, and the error becomes (el 1). Similarly, when (e2 +Δy) exceeds 1/2, the next coordinate becomes (y+1), and the error becomes (e2 1).

That is, the coordinate X of Pl.

The coordinates of P2 with respect to y are (X+Δx), (y+Δy), and the error is e+ 9.62 1). In this way, the center P3. ．． By repeatedly calculating P4, the xy coordinates corresponding to all pixels are obtained.

A more detailed explanation will be given based on the flowchart shown in FIG. First, the control circuit 3-3 controls the pickup coil 2-
2, read the coordinates of (X+,)'+), (x2°y2). This is the process shown in FIG. 4(a). Subsequent processing is indicated by alphabetic characters in parentheses. Based on this, the address calculation circuit 3-1 calculates Δx=(x2-xl)/n, Δy
= (y2-)'+ )/n ib). Next, in order to calculate the position of each pixel, the initial value is e) = O
, e2 =O, X=X+ + Y=y1. The current (x, y) coordinates at the start are Pi
(C). This calculation is repeated for i from 1 to n (d). The calculation ends when i becomes n (
e).

Calculate el = e1 + ΔX, e2 = e2 + Δyk (fl. If this calculated el is greater than 0.5, then (
gl, x=x+ l, and e+=e+ 1 (
h). If it is 0.5 or less, move on to the next process.

If e2 is greater than 0.5, (]), )'=)'+1. e
2=e+-1 (j). If it is 0.5 or less, the following process is performed. Next, the position of the next pixel is detected by setting i=i+l (kl.

In this process, there is division during calculation, and since the magnitude relationship is compared with 0°5, floating point calculation is required.

In order to process this at high speed, it is calculated by integer arithmetic according to the flowchart shown in FIG.

This is obtained by multiplying only the error calculation by 2n and moving the origin by -n. Note that this calculation can be performed separately in the x and y directions, making it possible to speed up the processing.

Based on the calculated coordinates, the control circuit 3-3 transfers the image data obtained by the line sensor 2-2 to the memory 3-2.
Store in.

Therefore, by providing the pickup coils 2-2 at both ends, a decrease in position accuracy due to operation using a hand scanner can be prevented.

Note that the reading surface is observed through the window 2-4 of the hand scanner, and the pickup coil 2-2 is
The control circuit 3-3 determines the reading area at a diagonal position t.
By storing the data in a storage circuit (not shown), it is possible to prohibit measurement beyond this area during measurement, and store only data within the area in the memory 3-2. That is, it becomes possible to replace part of the image data with other image data.

C. Effects of the Invention] As is clear from the above description, according to the present invention, since the amount of movement of the hand scanner can be detected using position data from the tablet, it is possible to accurately correspond between memory addresses and image reading positions. This makes it possible to improve operability,
This is extremely effective in improving accurate address correspondence and processing speed.

[Brief explanation of drawings]

FIG. 1 is a circular diagram of the present invention, FIG. 2 is a schematic diagram of an embodiment showing the scanning distortion correction method of the present invention, and FIG. 3 is a diagram for explaining the operation of the address calculation circuit of the present invention. FIG. 4 is a flowchart of the basic operation of the present invention, FIG. 5 is a flowchart of the high-speed processing operation of the present invention, FIG. 6 is a block diagram for explaining the operation of a conventional hand scanner, and FIG. 7 is a flowchart of the conventional hand scanner. FIG. 2 is a block diagram for explaining a hand scanner using a doublet. In the figure, 1 is a tablet, 2 is a hand scanner, and 3 is a tablet.
is an image processing device (word processor) No. 3) l + n) no. Fig. 6 Fig. 5

Claims (1)

[Scope of Claims] A system for reading an image on a tablet (1) with a hand scanner (2) and inputting image data to an image processing device (3), comprising: a line sensor (2-
A pickup coil (2-2) for reading both end positions of 1) from the tablet (1) is attached to the hand scanner (2), and the pickup coil (2-2)
Based on the position signal of the line sensor (2), the address calculation circuit 3-1 provided in the image processing device (3)
-1) A scanning distortion correction method characterized by calculating an address in which scanning distortion is corrected for each pixel.