JPH04239980A - Image rotation device - Google Patents

Abstract

PURPOSE:To excessively shorten the rotation processing time of a sentence, a character or an image by detecting a case when sub-patterns are all white or all black and writing it in a memory without executing rotation processing. CONSTITUTION:A data transferring circuit 7 divides data of the sentence or the image into the sub-patterns of (n)X(n) (n)is an integer) by a pattern analysis circuit 1 and transfers data of the sub-pattern. An all black-and-white detecting circuit 5 detects whether the sub-patterns are all white or all black and stops the processing of a rotation circuit at the time of detecting either of them.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus used for display and printout in an information processing apparatus, and more particularly to an image rotation apparatus for rotating image data.

0002

2. Description of the Related Art Image processing apparatuses generally perform processing such as enlarging, reducing, and rotating image data when displaying or printing characters, images, etc. input to an information processing apparatus or the like. Such an information processing device is shown in Figure 3.
As shown in the block diagram, it is comprised of an input device 9 for inputting characters, images, etc., a display device 8 for displaying processed characters, images, etc., a printing device 11 for printing, and an image processing device 10.

In the information processing device shown in FIG. 3, image data such as character images and graphic images for each character is inputted from the input device 9 to the image processing device 10, and the image processing device 10 generates a diagram including the graphics. A manuscript as shown in 4(a) is created. For example, if this document is a horizontally long A4 size and the display screen of the display device can only display up to the vertically long A4 size, the image processing device 10 reduces the document size and displays it. Furthermore, when printing this document on a printing device 11 whose print width is up to the short side of A4 size, it is necessary to print by rotating the document 90 degrees to the right or left.

Conventionally, an image rotation device for rotating image data has a pattern decomposition circuit 1 as shown in FIG.
2, a rotation circuit 13, a pattern assembly circuit 14, and an image memory 15, and rotates image data by the operation described below.

The pattern decomposition circuit 12 divides the rotated image data into sub-patterns 41 of n pixels x n lines (n is an integer) using a lattice as shown in FIG. 4(a).
42, ..., 48, first the subpattern 41
is output to the readout rotation circuit 13 for each line from the image memory 15 during the period T0 in FIG.

After all n lines have been input, the rotation circuit 13 performs rotation processing on the sub-pattern (the rotation processing will be explained later with reference to FIG. 7). The new n-line data of the rotated subpattern A is
During period T1 in FIG. 6, the data is written in another predetermined area of the image memory 15, at the position indicated by A in FIG. 4(b). Next, in the same manner, each subpattern is sequentially rotated in the order of B, C, . In this way, all subpatterns are rotated, and rotated image data as shown in FIG. 4(b) is obtained.

The actual rotation process will be explained using FIG. Figure 7 shows one sub-pattern (8 pixels x 8 lines).
The movement of data when rotated 90 degrees to the left is shown, but it is treated as one subpattern decomposed by the pattern decomposition circuit, and the subpattern 43 in FIG. 4(a) is shown in FIG. 7(a).
Shown below. The data of this sub-pattern is input to each shift register sequentially from shift 7 to shift 0, and one bit is sequentially input from data 7 (indicated by ○ in FIG. 7(b)) for each shift register (shifts 0 to 7). By writing each bit as a new 8 bits to the data 7 shown in FIG. 7(c) of the new sub-pattern, and repeating this until data 0,
A 90 degree rotation to the left is performed.

In addition, in the case of a 90 degree rotation to the right, when setting data in each shift register, data 0 to 7 are written, and this time, data 0 to 7 is written for each shift register, one bit at a time, as new 8 bits in a new sub. This is possible by writing in the data 7 shown in FIG. 7(c) of the pattern, and in the case of a 270 degree left and right rotation, the left and right sides are reversed in the case of a left and right rotation of 90 degrees, and the same process can be performed.

Furthermore, in the case of 180 degree rotation, FIG.
) is first read out, data 0-- are inverted to data 7-0, and written to data 7 in the new sub-pattern shown in Figure 7(c), then shift 1 is read out. This can be done by writing the data to data 6 and the shift 2 data to data 5.

0010

[Problems to be Solved by the Invention] In conventional image rotation devices, even if the subpattern data is all white or all black, processing is performed in the same way as normal processing. or black, there is no need to rotate.

[0011] In general, sentences, images, etc. have many white parts, and it takes a lot of time to rotate the sentences or images.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned drawbacks, to detect cases where sub-patterns are all white or all black, and to write the sub-patterns into memory without performing rotation processing. An object of the present invention is to provide an image rotation device that can significantly shorten the processing time for rotating sentences or images.

[0013]

[Means for Solving the Problems] The present invention provides an image rotation device having a pattern decomposition circuit, a rotation circuit, a pattern assembly circuit, and a memory, including an all black and white detection circuit;
A data transfer circuit that divides text or image data into n×n (n is an integer) subpatterns using a pattern decomposition circuit, and a data transfer circuit that transfers the data of the subpatterns, and a data transfer circuit that divides text or image data into n × n (n is an integer) subpatterns, and a data transfer circuit that divides text or image data into n × n (n is an integer) subpatterns. , or if all black is detected, and when either is detected,
The apparatus is characterized in that it includes an all black and white detection circuit that stops the processing of the rotation circuit.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained below with reference to the drawings.

FIGS. 1 and 2 are a functional block diagram of an image rotation device according to an embodiment of the present invention, and a time chart showing the rotation processing time of four sub-patterns in FIG. 1, respectively.

This embodiment is obtained by adding an all black and white detection circuit 5 and a data transfer circuit 7 to the conventional example shown in FIG.

In FIG. 1, as in the conventional case, the image data rotated by the pattern decomposition circuit 1 are
It is decomposed into sub-patterns as shown by b, ……, and c. Next, the decomposed sub-pattern A is read line by line from the image memory 4 during period T0 in FIG. The rotation circuit 2 performs rotation processing as in the conventional case, and at the same time, the all-black and white detection circuit 5 receives sub-pattern image data line by line.
It is detected whether all the sub-patterns are white or black, and if detected, a rotation stop signal 6 is output to the rotation circuit 2. In addition, the data transfer circuit 7 receives the image data as is for each line during the period T0 in FIG. 2, and outputs it to the pattern assembly circuit 3. The area is written in the position shown by A in FIG. 4(b).

Since the rotation stop signal 6 is output to the rotation circuit 2, the rotation process is immediately stopped, and processing of the second sub-pattern is started in the next period T1. Similarly, T1
The processing of the sub-pattern (B) is completed in the period T2, and the processing of the sub-pattern (C) is executed in the next period T2.

During the T2 period, the pattern decomposition circuit 1 outputs the sub-pattern C to the rotation circuit 2, the all-black and white detection circuit 5, and the data transfer circuit 7, and when all sub-patterns have been input, the rotation is stopped. Since the signal 6 is not output, the rotation circuit 2 performs rotation processing during the T3 period and outputs it to the pattern assembly circuit 3 for each line. The area is written in the position shown by C in FIG. 4(b).

[0020] In this way, if each sub-pattern is all white or all black, rotation processing is not performed;
It is possible to obtain rotated image data of the entire text or image, and conventionally, the period from T0 to T5 was required to process sub-patterns A, B, and C, but the embodiment of the present invention According to , it ends in the period T0 to T3.

[0021]

Effects of the Invention As explained above, the present invention detects cases in which sub-patterns are all white or all black and can be written into memory without performing rotation processing.
This has the effect of significantly shortening the processing time for rotating sentences, characters, and images.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of an embodiment of the present invention.

FIG. 2 is a time chart showing the rotation processing time of four sub-patterns in FIG. 1;

FIG. 3 is a functional block diagram of an example of a conventional image rotation device.

FIG. 4 is a diagram showing an image rotated 90 degrees to the left by a conventional image rotation device.

FIG. 5 is a functional block diagram of an example of an information processing device including an image processing device using a conventional image rotation device.

FIG. 6 is a time chart showing the rotation processing time of three sub-patterns in FIG. 5;

[Figure 7] One sub-pattern (8 pixels x 8 lines)
FIG. 6 is a diagram showing the movement of data when rotating 90 degrees to the left.

[Explanation of symbols]

1 Pattern decomposition circuit 2 Rotating circuit 3 Pattern assembly circuit 4 Memory 5 All black and white detection circuit 6 Rotation stop signal 7 Data delivery circuit

Claims (1)

[Claims] 1. An image rotation device comprising a pattern decomposition circuit, a rotation circuit, a pattern assembly circuit, and a memory, comprising an all-black and white detection circuit and a data transfer circuit, and the pattern decomposition circuit allows text and image rotation to be performed. a data transfer circuit that divides data into n×n (n is an integer) subpatterns and transfers data of the subpatterns;
Detect whether the subpattern is all white or all black,
An image rotation device comprising: an all black and white detection circuit that stops processing of the rotation circuit when any one of them is detected.