JP4174454B2 - Image processing device - Google Patents

Description

The present invention relates to an image processing apparatus of an image processing system that draws and outputs an image on a recording medium by an image output apparatus using input data transferred from the image output control apparatus.

FIG. 3 shows a change in the area when the real coordinate system rectangular data input by the page description language is drawn in the frame memory of an image output device such as a printer and converted from the real coordinate system to the integer coordinate system. It is a thing.
FIG. 3A shows an area of rectangular data when no rotation is performed. If the rectangular data input in the real number coordinate system is 5.5 x 3.5 (horizontal), the integer coordinates are first calculated by rounding up, rounding down, or rounding off the value after the decimal point. Need to be converted to Normally, the conversion method is always the same regardless of the rotation of the image data and the vertical and horizontal directions of the coordinate position. FIG. 3 shows a conversion method in which all values after the decimal point are rounded down. Thus, when the same conversion method is always used, a problem occurs when the image data is rotated.
For example, in the case of FIG. 3 which is a conversion method in which all values after the decimal point are rounded down, the rectangular data area designated by the real number coordinate of 5.5 × 3.5 in the horizontal direction as shown in FIG. In the case of conversion, all values after the decimal point are rounded down, and the converted rectangular data area is 5 × 3 in length. In this case, even when the image data is rotated, the rectangular data area must be 5 × 3 or 3 × 5. However, in reality, the result is not as expected.
FIG. 3B shows an area of rectangular data when the rectangular data in the real number coordinate system specified in FIG. 3A is rotated 90 degrees to the right and then converted to integer coordinates. Before the rotation, there was a coordinate area below the decimal point in the lower right position, but the coordinate area below the decimal point has moved to the lower left position due to the rotation. The decimal point area moved to the left side by this movement of the position is enlarged by the conversion method of rounding down after the decimal point. As a result, the rectangular data after being rotated 90 degrees to the right is 4 × 5 in width.
Originally, the area of the rectangular data after the integer coordinate conversion in the case of not rotating is 5 × 3 in the horizontal direction, so if it is rotated 90 degrees to the right, it must be 3 × 5 in the horizontal direction. However, since the width is actually 4 × 5, drawing of the same rectangular data is different between the case of not rotating and the case of rotating 90 degrees to the right.

FIG. 3C shows an area of rectangular data when the rectangular data in the real number coordinate system specified in FIG. 3A is rotated 90 degrees to the left and then converted to integer coordinates. Before the rotation, there was a coordinate area below the decimal point in the lower right position, but the coordinate area below the decimal point has moved to the upper right position due to the rotation. The decimal point area moved upward by this movement of the position is enlarged by the conversion method of rounding down after the decimal point. As a result, the rectangular data after being rotated 90 ° to the left is 3 × 6 in width.
Originally, the area of the rectangular data after the integer coordinate conversion in the case of not rotating is horizontal 5 × vertical 3, so when rotated 90 degrees to the left, it must be horizontal 3 × vertical 5. However, since it actually becomes horizontal 3 × vertical 6, drawing of the same rectangular data is different when it is not rotated and when it is rotated 90 degrees to the left.
FIG. 3D shows an area of rectangular data when the rectangular data in the real number coordinate system specified in FIG. 3A is rotated 180 degrees and then converted to integer coordinates. Before the rotation, there was a coordinate area below the decimal point in the lower right position, but the coordinate area below the decimal point has moved to the upper left position due to the rotation. The decimal point area moved to the upper left side by the movement of this position is enlarged by the conversion method of rounding down after the decimal point. As a result, the rectangular data after 180 ° rotation is 6 × 4 in width.
Originally, the area of the rectangular data after the integer coordinate conversion in the case of not rotating is horizontal 5 × vertical 3, so when rotated 180 degrees, it must be horizontal 3 × vertical 5. However, since the width is actually 6 × 4, drawing of the same rectangular data is different between the case of not rotating and the case of rotating 180 degrees.
For example, Patent Document 1 provides a method and apparatus for rotating an image 90 ° or 90 ° K times faster.
Japanese Patent Laid-Open No. 06-231236

As described above, despite the same image data, there arises a problem that the drawing result differs depending on whether the image is rotated or not. As a method for solving this problem, there is a method of performing rotation processing after integer conversion, but the data amount converted to raster data after integer conversion is enormous in comparison with vector data of real number coordinates. Then, there is a problem that the time for the subsequent rotation process increases and the performance deteriorates.
It is an object of the present invention to provide an image processing apparatus that can obtain the same drawing result from the same image data while improving the image processing efficiency.

In order to achieve the above object, according to the first aspect of the present invention, in the image processing apparatus for converting vector-format vector rectangular data into raster-format raster rectangular data, at least one side is a value including a decimal value. When converting vector rectangular data to raster rectangular data, a decimal value processing means for performing processing of truncating the decimal value, and rotation processing is performed on the vector rectangular data whose length of at least one side includes a decimal value. A switching means for switching from the process of rounding down the decimal value to the process of rounding up according to the rotation angle of the vector rectangular data .
According to a second aspect of the invention, the image processing apparatus according to claim 1, wherein the switching means, the length of one side in the longitudinal direction of the vector rectangle data rotation process of 90 degrees to the right has been performed including fractional value In this case, the process is switched from the process of rounding down the decimal value to the process of rounding up .
According to a third aspect of the present invention, in the image processing apparatus according to the first aspect, the length of one side in the horizontal direction of the vector rectangular data subjected to the left 90 degree rotation processing includes a decimal value. In this case, the process is switched from the process of rounding down the decimal value to the process of rounding up .
According to a fourth aspect of the present invention, in the image processing apparatus according to the first aspect, when the switching unit includes a fractional length of one side in the vertical direction of the vector rectangular data subjected to the 180 degree rotation process. If the length of one side in the horizontal direction of the vector rectangular data subjected to the 180 degree rotation process includes a decimal value, the process is changed from the process of rounding down the decimal value to the process of rounding up. It is characterized by switching .

According to the present invention, when the input data is output to the image output device as the image data, if the image data needs to be rotated, the input specified by the real number coordinates in consideration of the rotation direction of the image data. By performing the conversion process for converting the data into image data of integer coordinates, the same output result as when the image data is not rotated can be obtained even when the image data is rotated.
Further, according to the present invention, processing can be performed at high speed even when compared with the case of performing rotation processing on raster data.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that the input data is a page description language composed of basic graphic drawing commands including characters, graphics, and images.
FIG. 1 is a flowchart showing an image processing method of the present invention. Specifically, it is a flowchart showing a flow of processing for rotating input image data in a real coordinate system and converting it to integer coordinates in a page description language. In the flowchart according to the present embodiment, as an example, when converting to integer coordinates, values after the decimal point of the real number coordinates are rounded down.
First, when image data is input, it is determined whether the image data needs to be rotated (S1). Whether or not image data needs to be rotated is determined by using information on the paper size and longitudinal direction of a page specified by the page description language, information on a paper tray of a printer or the like that outputs data, and the like.
If rotation is not necessary as a result of the determination, it is determined whether or not there is a value after the decimal point in the coordinates of the next designated image data (S2). Conversion to integer coordinates when there is no value after the decimal point is “integer coordinates = real number coordinates” (S3). Conversion to integer coordinates when there is a value after the decimal point is “integer coordinates = real number coordinates with values after the decimal point truncated” (S4, S5).

Next, it is processing when image data is rotated. When rotation processing is necessary, first, the designated real number coordinates are converted according to the rotation direction. Next, it is determined whether or not there is a value after the decimal point (S7). If there is no value after the decimal point, conversion to integer coordinates is "integer coordinates = real number coordinates" (S8). If a value after the decimal point is specified, the processing method for integer conversion is changed as follows according to the rotation direction.
If the direction of rotation was clockwise 90 degrees ( "Y" in S9), an integer transform in the transverse direction of the coordinate in the image data is "integer coordinates = real coordinates decimal values were truncated" ( S10), an integer transform in the vertical direction of the coordinate in the image data is "integer coordinates = real coordinates fractional values were rounded up" (S11). In this way, when converting to integer coordinates, separate processing is performed on the vertical and horizontal coordinates of the image data.
If the rotation direction was left 90 degrees ( "N" at S9, "Y" in S12), the real coordinate integer transform in the transverse direction of the coordinate in the image data that has been raised off the value of the "integer coordinates = decimal becomes "(S13), an integer transform in the vertical direction of the coordinate in the image data is" integer coordinates = real coordinates decimal values were truncated "(S14).
When the rotation direction is 180 degrees (“N” in S12), the integer conversion of the horizontal coordinate in the image data becomes “integer coordinate = real number coordinate rounded up after decimal point” (S15). The integer conversion of the vertical coordinates in the image data becomes “integer coordinates = real number coordinates rounded up after the decimal point” (S16).
The scan line rule for scan line conversion (processing for converting data specified by vector coordinates to raster coordinates) performed when converting from a real number coordinate system to an integer coordinate system is a Windows (registered trademark) rule (specified) The processing according to the present embodiment is changed both in the case of the image data that does not include the lower right coordinates of the image data and the PS rule (including the coordinates of the lower right of the specified image data). do not have to.
Also, since rotation processing is performed before scanline conversion, there is no need to perform rotation processing on raster data that has been converted to scanline, and processing that performs rotation processing after conversion to integer coordinates. Compared with the configuration, the processing can be performed at high speed.
In addition, since this process does not depend on hardware, all of this process can be performed by an image output control apparatus such as a personal computer, and all of this process can be performed by an image output apparatus such as a printer. Is also possible. Furthermore, it is possible to have all of this processing in both, and to distribute the processing according to the performance and state of the image output control device and the image output device.

The function and effect of the present invention will be described with reference to FIG. FIG. 2 shows a region when the conversion process from the image data in the real number coordinate system to the integer coordinate system is performed using the processing method described in FIG.
As shown in FIG. 2 (b), if the direction of rotation of the right 90 degrees, integer transform in the transverse direction of the coordinate in the image data is "integer coordinates = real coordinates decimal values were truncated", image data Since "integer coordinates = real coordinate point following values were rounded up" is an integer transform in the vertical direction of the coordinates in the rectangular data after the rotation becomes horizontal 3 × 5 vertical. Since the rectangular data in the case of not rotating shown in FIG. 2A is horizontal 5 × vertical 3, the regions of the rectangular data are the same when not rotated and when rotated 90 degrees to the right, and the same output result can be obtained. it can.
As shown in FIG. 2 (c), if the direction of rotation of the left 90 degrees, integer transform in the transverse direction of the coordinate in the image data is "integer coordinates = real coordinates fractional values were rounded up", the image data Since "integer coordinates = real coordinate point following values were truncated" is an integer transform in the vertical direction of the coordinates in the rectangular data after the rotation becomes horizontal 3 × 5 vertical. Since the rectangular data in the case of not rotating shown in FIG. 2A is horizontal 5 × vertical 3, the regions of the rectangular data match when not rotated and when rotated 90 degrees to the left, and the same output result can be obtained. it can.
As shown in FIG. 2D, when the rotation direction is 180 degrees, the integer conversion of the horizontal coordinate in the image data is “integer coordinate = real number coordinate rounded up after the decimal point”, and the vertical coordinate in the image data. Since the integer conversion of the direction coordinates is “integer coordinates = real number coordinates rounded up after the decimal point”, the rotated rectangular data is 5 × 3 in the horizontal direction. Since the rectangular data in the case of not rotating shown in FIG. 2A is horizontal 5 × vertical 3, the regions of the rectangular data are the same when not rotating and when rotating 180 degrees, and the same output result can be obtained. .

It is a flowchart which shows the image processing method which concerns on embodiment of this invention. It is a figure which shows the area | region at the time of performing the conversion process from the image data of the real number coordinate system which concerns on embodiment of this invention to an integer coordinate system. It is a figure which shows the area | region at the time of performing the conversion process from the image data of the conventional real coordinate system to the integer coordinate system.

Claims (4)

In an image processing apparatus for converting vector-format vector rectangle data into raster-format raster rectangle data,
A decimal value processing means for performing processing of truncating the decimal value when converting vector rectangular data whose length of at least one side includes a decimal value into raster rectangular data;
When the rotation processing is performed on the vector rectangular data in which the length of at least one side includes a decimal value, switching means for switching from the process of rounding off the decimal value to the process of rounding up according to the rotation angle of the vector rectangular data When,
An image processing apparatus comprising: The switching means is
2. The image according to claim 1, wherein when the length of one side in the vertical direction of the vector rectangular data that has been rotated 90 degrees to the right includes a decimal value, the processing is switched from the process of rounding down the decimal value to the process of rounding up. Processing equipment . The switching means is
2. The image according to claim 1, wherein when the length of one side in the horizontal direction of the vector rectangular data subjected to the left 90 degree rotation processing includes a decimal value, the processing is switched from the process of rounding down the decimal value to the process of rounding up. Processing equipment . The switching means is
When the length of one side in the vertical direction of the vector rectangle data subjected to the rotation process of 180 degrees includes a decimal value, switch from the process of rounding down the decimal value to the process of rounding up,
2. The image processing according to claim 1, wherein when the length of one side in the horizontal direction of the vector rectangular data subjected to the rotation process of 180 degrees includes a decimal value, the process is switched from the process of rounding down the decimal value to the process of rounding up. Equipment .

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