JPH0563959A - Method and device for processing picture - Google Patents

Abstract

PURPOSE:To obtain a picture rotated at right angles from the picture stored in a page memory in a short time and with simple device. CONSTITUTION:The picture data supplied from a picture data supply part 1 such as a computer and a picture reader is stored in a page memory 3 temporarily. Each (n) picture element is supplied to a picture element rotation part 5 from this page memory 3, the rotation processing is performed for each (n)X(n) picture element to be restored in the page memory 3. Then, data is outputted in a byte unit from the page memory 3 in the prescribed order, and this is outputted serially by a parallel/serial converter 4 to obtain the picture rotated at right angles. The rotation processing is divided into two simple processings; an inverted processing for each block and a reading processing. The entire processing time is shortened and the processor itself is simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method and apparatus for rotating input image data by rotating it 90 degrees leftward or rightward.

[0002]

2. Description of the Related Art Conventionally, in a raster type output device such as a printer having a page memory capable of storing at least one page of output data, an input image is rotated 90 ° to the left or to the right to be output. If the next 2
Often one of the two methods is used.

The first method is basically based on software, and when the image data is stored in the page memory, the image data is rotated by 90 ° in advance and stored. For example, when the processing data per time determined by hardware such as a printer is, for example, 1 byte, first, as shown in FIG. 15, line data which is the same as the bit number of 1 byte or an integral multiple thereof, that is, 8 lines or 8 lines in this case. The line data of xn (n is a positive integer) lines is stored in the buffer memory.

Next, the data stored in the buffer memory is transposed and stored in the page memory. That is, the horizontal data in the buffer memory is rearranged and stored in the page memory in the vertical direction. As a result, an image rotated by 90 ° can be obtained in the page memory. Therefore, when this image is printed out, it may be read out in the horizontal direction and sequentially output. Although FIG. 15 schematically shows the case where one page of image data is divided into four,
Actually, it is divided into smaller pieces for processing.

In the first method, hardware may be used as an auxiliary, but since it is basically realized by software, various kinds of rotation processing can be performed.

The second method is basically based on hardware, and is configured so that the page memory can be output in both the horizontal and vertical directions. Then, the input image is stored in the page memory as it is, and the data in the vertical direction is sequentially output at the time of output, and this is printed out in the horizontal direction. With this, an image rotated by 90 ° can be obtained.

[0007]

The above-mentioned conventional image processing method has the following problems. That is, in the first method, the software performs the process of replacing the data in the horizontal direction in the buffer memory in the vertical direction, so that this process takes a relatively long time.

When the capacity of the buffer memory is small, the above replacement process is performed and then this is input to the page memory before receiving the next data. Therefore, an external data supply source, for example, a host computer, is involved in this during the data replacement period, and there is a problem that other processing cannot be performed during that period.

In the second method, if the unit of processed data determined by hardware is 1 byte (8 bits), at least 8 × 8 is required to enable output in both the horizontal and vertical directions. Memory elements are required.

Further, since independent wiring control is required for each of the 64 memory elements, the scale of hardware increases. Further, it is not possible to form a page memory using a highly integrated memory device.

Therefore, the present invention solves the above-mentioned problems, and proposes an image processing method and apparatus capable of performing rotation processing in a short time and simplifying the configuration of the apparatus. is there.

[0012]

In order to solve the above-mentioned problems, in the present invention, in the image processing method of rotating input image data by 90 ° in the left direction or the right direction and outputting the image data, H × It is divided into V (H and V are positive integers) small blocks, and the small block is divided into n × n (n is a positive integer) pixels, and a row and a column consisting of n pixels in the small block. When the left rotation image is output by performing the transposition process of, the output is performed in a predetermined order in units of n pixels for one row from each small block after the transposition process, and when the right rotation image is output, It is characterized in that after the transposition processing, the order of the columns of the respective small blocks is reversed, and then each small block outputs one row of n pixels as a unit in a predetermined order.

In order to achieve the above-mentioned image processing method, the present invention has a page memory for storing at least one page of image data, and the image data in this page memory is rotated by 90 ° and output. In the image processing apparatus, the image data output from the page memory in units of n pixels is rotated by n × n pixels and then re-inputted into the page memory, and the page memory outputs in units of n pixels. A parallel / serial conversion means for converting the image data into serial data and outputting the serial data, and the image data after the partial rotation processing in the page memory is read in a predetermined order according to the rotation direction. Is.

[0014]

The original image of FIG. 1 is divided into H × V, here 4 × 3, small blocks, and each small block is divided into n × n, here 8 × 8 pixels. Next, as shown in FIG. 3, the transposing process for replacing the rows and the columns is performed on each small block to obtain the image after the transposing process shown in FIG.

Next, the image data after the transposition processing is read out in the reading order shown in FIG. 4, and is output as shown in FIG. As a result, an image obtained by rotating the original image by 90 ° to the left as shown in FIG. 7 is obtained.

When the original image is rotated 90 ° to the right,
Instead of the rotation process of FIG. 2, a process in which the order of the columns of the respective small blocks is also changed as shown in FIG. 8 is first performed.

Then, the image data in which the order of the columns is changed is read out in the reading order shown in FIG.
By outputting in the array shown in 0, an image obtained by rotating the original image by 90 ° to the right as shown in FIG. 11 is obtained.

[0018]

Embodiments of the image processing method and apparatus according to the present invention will now be described in detail with reference to the drawings.

FIGS. 1 to 6 are explanatory views for explaining the image processing method of the present invention, for example, when an original image stored in a page memory is rotated 90 ° to the left and output. In this image processing method, first, as shown in FIG. 1, the input original image is divided into H × V (H and V are positive integers) small blocks, and each small block is further divided into n × n (n: Positive integer) pixel data. As for n, 1 byte which is a normal processing unit, that is, 8 bits is practical.

Next, as shown in FIG. 2, the image data is transposed for each small block. This is an operation of rearranging pixel data in the horizontal direction in the vertical direction. That is, as shown in FIG. 3, the first row (horizontal direction) of the original image becomes the first column (vertical direction) by the transposition process, the second row becomes the second column, and so on. 3rd to 8th columns
It becomes a line.

From the image data obtained by transposing all the H × V small blocks in this way, one row of n pixels (8 in this case) in each small block is used as a unit, as described below. A rotated image obtained by rotating the original image 90 ° to the left by selecting the reading order as appropriate (Fig. 7).
Is obtained.

FIGS. 4 to 6 show data after transposition processing (FIG. 2).
It is explanatory drawing explaining the order which reads out. FIG. 4 shows the order in which the image data after transposition processing in the page memory is read out for one row of each block, where n = 8 pixels as a unit. The number in parentheses is the address of the page memory. That is, in this example, the data of the address 31 is read first, the data of the address 63 is read second, and the data of the address 95 is read third. In the same manner, all the data are read out according to the reading order.

Next, the image data thus read out is output so that one line is V = 3 blocks as shown in FIG. This is because the vertical direction of the original image (FIG. 1) is composed of V blocks, and if this is rotated 90 °, the horizontal direction becomes V blocks.

FIG. 6 shows the relationship between the transposed image structure and the output image in the case of the 90 ° rotation processing in the left direction. In this example, the number of bytes of one line in the transposed image is L = 4, the number of bits constituting one byte is B = 8, and the total number of lines is P = 24. Therefore, one line of the output image is composed of P / B = 3 bytes. Thus, one page has L × B = 32 lines.

Further, for example, the read start address of the first line is L × B-1 = 31, and hereinafter, each address of L × B = 32 is read. The read start address of the second line is L × B−1−L = 27, and the read addresses are read every 32 addresses as in the first line. In this way, by outputting the image data after the transposition processing from the page memory in a predetermined order, an image obtained by rotating the original image by 90 ° to the left can be obtained as shown in FIG.

To obtain an image rotated 90 ° to the right, first, as shown in FIG. 8, the order of the columns of the respective small blocks in the transposed image (FIG. 2) is reversed, that is, the first column is changed to the eighth column. In addition, partial rotation is performed for each small block in a form in which the second column is rearranged to the seventh column, and the third to eighth columns are rearranged to the sixth to first columns.

Next, from the image data in which the columns are exchanged, one row of pixel data n = 8 in each small block is set as one unit and read out in the reading order shown in FIG. 9, and the read data is arranged as shown in FIG. To output. This makes it possible to obtain an output image obtained by rotating the original image (FIG. 1) 90 ° to the right as shown in FIG. Note that FIG. 12 shows the relationship between the transposed row reverse order image (FIG. 8) and the output image (FIG. 11) when the image is rotated 90 ° to the right.

As described above, the present invention divides the image rotation process into two processes, that is, a partial transposition process and an output process for outputting the image data after the transposition process in a predetermined order. , This simplifies each process. Therefore, it becomes easy to directly implement each process by hardware.

FIG. 13 shows the structure of an image processing apparatus for achieving the above-described image processing method. The image data supplied from the image data supply unit 1 such as a computer or an image reading device is temporarily stored in the page memory 3 as it is via the interface 2. When the image is output as it is without being rotated, it is output as it is from the page memory 3 through the parallel / serial converter 4.

When the image is rotated by 90 ° and output, the data in the page memory 3 is transferred in 1-byte units to the pixel rotation unit 5.
Are stored in the page memory 3 again after being subjected to transposition processing, column reverse order processing, etc. for every 8 × 8 pixels. As a result, the image data in the page memory 3 is
Each block of the original image is transposed or processed in the column reverse order. If this is output according to the above-mentioned reading order, a rotated image can be obtained.

In the case of a printer, for example, such rotation processing is controlled by the MPU 6 for controlling the printer and the image processing control section 7.

In such an image processing apparatus, even when the image data is already stored in the page memory 3, the data for each block read from the page memory 3 is processed by the pixel rotating unit 5 and the page is re-processed. If the images are stored in the same position of the memory 3, the image rotated by 90 ° can be easily output. Therefore, complicated storage management and read order control are not required, and the device configuration is simplified.

Further, in the rotation processing, it is not necessary that all the image data is stored in the page memory 3, and at the time when only 8 lines are input to the page memory 3, the processing is performed by the pixel rotation unit 5 every 8 × 8 pixels. Therefore, the waiting time of the image data supply unit 1 is eliminated.

If the original image data is received by, for example, a buffer memory of 8 lines or more, the output of this buffer memory is directly processed by the pixel rotation unit 5 and stored in the page memory 3 so that each block is processed. It is also possible to obtain transposed image data for each.

Further, according to the present invention, it is easy to obtain a 180 ° rotation, a reversed image, etc. by appropriately selecting the reverse processing of rows or columns in the small block after the transposing processing and the reading order.

Further, according to the present invention, the page memory 3 is left with the image data after the transposition processing or the image data obtained by reversing the image data in the reverse column order. This image data has n lines,
In this example, every 8 lines are stored in the same area as the original image data.

Therefore, if the present invention is applied to, for example, a facsimile machine, it is possible to secure the data necessary for overlap at the time of output of divided pages using a landscape at consecutive addresses on the page memory as described below. Management of page memory becomes easy.

That is, in the facsimile apparatus, even if the transmitting side transmits an original document of portrait output of A3 size (portrait image such as portrait) shown in FIG. 14A, the receiving side has a recording capacity of A3 size. If not, this will be recorded in the A4 size set as standard.

In this case, in order to obtain an image of the same size on the receiving side as on the transmitting side, the received image is temporarily stored in the page memory, and this is divided into upper and lower parts as shown in FIG. Then, each image is recorded as an A4 size landscape output (a landscape image such as a landscape image) rotated by 90 °, and this can be pasted up and down.

At this time, it is general to provide an overlap area as a bonding margin, and in the present invention, the data in the overlap area is stored as it is in correspondence with the last read portion of the page memory. All you have to do is save the data and output it again on the next page.

On the other hand, conventionally, after 90 ° rotation, the data in the overlap area is not always stored in the final read portion of the page memory, so that address management of the data becomes troublesome.

[0042]

As described above, according to the present invention, the original image is divided into small blocks, the transposing process is performed for each small block, and then the data for one row of each small block is defined as a unit. The output is made in the order of.

Therefore, according to the present invention, each process, that is, the transposing process and the reading process is simplified, so that the total processing time is shortened and the rotation process can be easily performed with simple hardware. effective.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating an original image in an image processing method according to the present invention.

FIG. 2 is an explanatory diagram illustrating an image after transposition processing.

FIG. 3 is an explanatory diagram illustrating transposition processing.

FIG. 4 is an explanatory diagram illustrating a reading order when 90 ° counterclockwise rotation is performed.

FIG. 5 is an explanatory diagram illustrating an address of a page memory corresponding to an output image when rotated to the left by 90 °.

FIG. 6 is an explanatory diagram illustrating a relationship between a transposed image and an output image when rotating 90 ° to the left.

FIG. 7 is an explanatory diagram illustrating a 90 ° left rotation image.

FIG. 8 is an explanatory diagram illustrating an image after a column reverse order process of a transposed image.

FIG. 9 is an explanatory diagram illustrating a reading order during 90 ° clockwise rotation.

FIG. 10 is an explanatory diagram illustrating a page memory corresponding to an output image when rotated by 90 ° clockwise.

FIG. 11 is an explanatory diagram illustrating a 90 ° right rotation image.

FIG. 12 is an explanatory diagram illustrating a relationship between a transposed row reverse order image and an output image when rotating 90 ° clockwise.

FIG. 13 is a configuration diagram of an image processing apparatus according to the present invention.

FIG. 14 is an explanatory diagram illustrating overlap output.

FIG. 15 is an explanatory diagram illustrating an image processing method according to a conventional example.

[Explanation of symbols]

 1 image data supply unit 2 interface 3 page memory 4 parallel / serial converter 5 pixel rotation unit 6 MPU 7 image processing control unit

Front page continuation (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G06F 15/66 350 8420-5L G09G 5/36 8121-5G

Claims (2)

[Claims] 1. An image processing method for rotating input image data by 90 ° to the left or right and outputting the divided image data into H × V (V, H is a positive integer) small blocks. In addition, the small block is divided into n × n (n is a positive integer) pixels, the row and column consisting of the n pixels in the small block are transposed, and a left-rotated image is output. In the case of outputting from the respective small blocks after the transposition processing in a predetermined order in units of n pixels for one row, and when outputting a right-rotated image, the columns of the respective small blocks after the transposition processing are output. After reversing the order, an image processing method is characterized in that n pixels for one row are output in a predetermined order from each of the small blocks. 2. An image processing apparatus having a page memory for storing at least one page of image data and outputting the image data in the page memory by rotating it by 90 degrees, and outputting from the page memory in units of n pixels. Image data output from the page memory in units of n pixels are serially converted and output. An image processing apparatus comprising serial conversion means, wherein the image data after the partial rotation processing in the page memory is read in a predetermined order according to the rotation direction.