JPH0571892U - Image enlargement processing circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a clear enlarged image without increasing overlay bits. [Composition] A comparator 1 for comparing the overlay data of the first line with the image data, image data is selected when the overlay data does not exist, and data having a value opposite to the overlay data is selected when the overlay data exists. Selector 2 and comparator 3 for comparing overlay data of the second line and image data
A selector 4 for selecting image data when overlay data does not exist and selecting data having a value opposite to the overlay data when overlay data exists; an interpolating means 5 for interpolating the image data; Pixel enlarging means 6 for enlarging line overlay data
And a selector which outputs data having a value equal to the overlay data when the pixel enlarging means 6 is outputting the overlay data, and outputs data from the interpolating means 5 when the pixel enlarging means 6 is not outputting the overlay data. And an image enlargement processing circuit including.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an image enlarging processing circuit, and more particularly, to improvement of displaying an overlay character in an image enlarging processing circuit for enlarging image data.

[0002]

[Prior Art]

 In the conventional apparatus, when the image data is 8 bits, it has 1 bit as an overlay for character information. In this case, since the value of the image data under the overlay is stored as it is, the image is accurately interpolated even when the image data is enlarged by the interpolation circuit.

However, since the overlay-only bit must be provided, the entire system becomes 9 bits, and there is a problem that the frame memory of the image in particular becomes large.

[0004]

[Problems to be solved by the device]

 Therefore, from the viewpoint of cost reduction, there is also a plan to allocate characters from $ 00 to $ FE to the image and $ FF to the overlay by using the method of overlaying characters on the image data, and using 8 bits.

However, according to this method, since the image data under the overlay is lost, if the interpolation is performed as it is, $ FF of the overlay is also used as the image data in the interpolation calculation, so that the character is blurred. Occurs. That is, in this case, as shown in FIGS. 10 and 11, blurring occurs due to generation of interpolation data between the image data and the overlay data.

Therefore, there is a problem that a blur (c) as shown in FIG. 13 occurs in an image composed of the image (a) and the overlay character (b) as shown in FIG.

The present invention has been made to solve the above problems, and it is possible to obtain a clear image even if the image is enlarged without increasing the number of bits for overlay data. It is to provide a processing circuit.

[0008]

[Means for Solving the Problems]

 A first means for solving the above-mentioned problem is to receive a first comparator for comparing the overlay data of the first line with the image data, and a data having a value opposite to the value of the overlay data and the image data, According to the comparison result of the first comparator, when the overlay data does not exist, the image data is selected, and when the overlay data exists, the first selector that selects the data of the value opposite to the overlay data value, and the second line When the second comparator that compares the overlay data and the image data of, and the data and the image data of the value opposite to the value of the overlay data are received, and the overlay data does not exist according to the comparison result of the second comparator, If you select image data and overlay data exists, overlay data The second selector that selects the data of the opposite value, the interpolation means that receives the output data of the first selector and the second selector, and interpolates the image data, and the overlay data of the first line. It receives the pixel enlargement means for enlargement and the output of the interpolation means and the value data equal to the overlay data, and when the pixel enlargement means outputs the overlay data, outputs the data of the same value as the overlay data. Is provided with a third selector that outputs data from the interpolating means when no overlay data is output from the device.

[0009]

[Action]

 In the present invention, since the interpolated data is generated at the boundary between the overlay data and the image data from the data having the opposite value of the overlay data and the image data, the overlay data can be displayed clearly. . Then, without having the dedicated overlay bit, the overlay data can be judged and the interpolated data can be generated, and the image quality equal to or higher than that of the system having the dedicated overlay bit can be realized.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In this figure, 1 is a comparator for comparing the line 1 overlay data ($ FF) with line 1 image data, and 2 is a selector for selecting line 1 image data and data $ 00 according to the output of the comparator 1. 3 is a comparator that compares the overlay data ($ FF) of line 2 with the image data of line 2; 4 is a selector that selects the image data of line 2 and data $ 00 according to the output of comparator 3; An interpolator such as a pipeline circuit, 6 is a pixel enlargement circuit that enlarges overlay data, 7 is a linear interpolation circuit that interpolates image data, and 8 is an output of the linear interpolation circuit 7 and an overlay according to the output of the pixel enlargement circuit. It is a selector that switches between data ($ FF).

Further, FIG. 2 is a flowchart showing the flow of operation, FIG. 3 is a level diagram of a signal before interpolation, FIG. 4 is a level diagram of a signal after interpolation, FIG. 5 is an explanatory diagram showing a level of a signal after interpolation, and FIG. FIG. 4 is an explanatory diagram showing an image after interpolation.

The operation of the apparatus of this embodiment having the above-described configuration is as follows. In this circuit, line 1 and line 2 are supplied to the circuit of the present embodiment as image data, and interpolation data to be located in the middle is generated from these line 1 and line 2.

In the portion where the overlay data ($ FF) is not generated, the selector 2 and the selector 4 select the image data according to the comparison result of the comparator 1 and the comparator 3. As a result, the linear interpolation circuit 7 generates interpolation data from the image data (FIG. 2). Then, since no overlay data is generated, the selector 8 is switched to the output side of the linear interpolation circuit 7, and the data interpolated by the linear interpolation circuit 7 is output (FIG. 2).

Next, consider the boundary between the portion where the overlay data ($ FF) is generated and the image data. Here, $ FF is generated on the image data side of line 2, and only normal image data is generated on the image data of line 1. Therefore, the selector 4 is switched to the external data ($ 00) side by the output of the comparator 3. On the other hand, since the normal image data is input on the line 1 side, the image data passes through the selector 2. As a result, the linear interpolation circuit 7 generates interpolation data from the image data and the external data ($ 00). As shown in FIG. 4c, this interpolated data is data having a lower level than the image data (a) and the overlay data (b).

Therefore, the data complemented by the above operation is shown in FIG. The numbers enclosed in squares are the data before interpolation, and the data not enclosed in squares are the data generated by the interpolation of this embodiment. In addition, it is shown in decimal here. In this example, [128] indicates image data and [256] indicates overlay data. Therefore, the part surrounded by the broken line c is the data generated at the boundary part between the overlay data and the image data, and forms the data corresponding to the undershoot. As a result, the overlay data can be displayed clearly as shown in FIG.

Then, consider a portion in which overlay data ($ FF) is generated in line 1 and line 2. Here, overlay data ($ FF) is generated in line 1 and line 2. Therefore, both the selectors 2 and 4 are switched to the external data ($ 00) side by the outputs of the comparators 1 and 3. As a result, in the linear interpolation circuit 7, interpolation data is generated from the external data ($ 00). Here, the selector 8 is switched by the overlay data ($ FF) that has passed through the pixel expansion circuit 6, and the data $ FF is output.

Different effects can be obtained depending on the image interpolation method and the overlaying method. Even with the linear interpolation similar to the above description, the interpolation data of this embodiment appears on the opposite side as shown in FIG.

On the other hand, in the case of error dispersion expansion (640 expansion), as shown in FIG. 8, interpolation is performed so as to surround the periphery of the overlay character. Here, the error dispersion enlargement (640 enlargement) is a method of generating complementary enlargement data at a position surrounded by original image data, as shown in FIG. Note that FIG. 9 shows an example of double enlargement.

As described above, by generating the interpolation data from the image data value and the opposite value ($ 00) of the overlay data value ($ FF) at the boundary portion between the overlay data and the image data, The overlay data will be displayed clearly. In the above embodiment, the data of the value of $ 00 is used to generate the interpolation data, but other values may be used without any problem. Although the case where the overlay data is $ FF has been described, conversely, when the overlay data is $ 00, the interpolation data may be generated from $ FF and the image data. Good.

As described above, in the present embodiment, only by adding two comparators and three selectors to the conventional circuit, the overlay data can be determined even in the system having no dedicated overlay bit. Then, the interpolated data is generated, and the image quality equivalent to or higher than that of the system having the dedicated overlay bit can be realized.

[0021]

[Effect of the device]

 As described in detail above, in the present invention, the interpolation data is generated at the boundary portion between the overlay data and the image data from the value ($ 00) opposite to the value ($ FF) of the overlay data and the value of the image data. By doing so, the overlay data will be displayed clearly. Then, without having the dedicated overlay bit, it is possible to determine the overlay data and generate the interpolation data, and to realize the image quality equal to or higher than that of the system having the dedicated overlay bit.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of operations of the first embodiment.

FIG. 3 is a waveform diagram showing an original signal waveform.

FIG. 4 is a waveform diagram showing a signal waveform in the first embodiment.

FIG. 5 is an explanatory diagram showing signal levels in the first embodiment.

FIG. 6 is an explanatory diagram showing an example of an image in the first embodiment.

FIG. 7 is an explanatory diagram showing an example of an image in the embodiment of the present invention.

FIG. 8 is an explanatory diagram showing another image example in the embodiment of the present invention.

FIG. 9 is an explanatory diagram showing an example of enlargement in the embodiment of the present invention.

FIG. 10 is a waveform diagram showing a signal waveform by interpolation by a conventional device.

FIG. 11 is an explanatory diagram showing signal levels in interpolation by a conventional device.

FIG. 12 is an explanatory diagram showing an example of an image before interpolation.

FIG. 13 is an explanatory diagram showing an example of an image in the conventional apparatus.

[Explanation of symbols]

 1,3 Comparator 2,4,8 Selector 5 Interpolator 6 Pixel enlargement circuit 7 Linear interpolation circuit

Claims (1)

[Scope of utility model registration request] 1. A first comparator (1) for comparing overlay data of a first line with image data, and a first comparator (1) which receives data having a value opposite to the value of overlay data and image data. According to the comparison result of 1), when the overlay data does not exist, the image data is selected, and when the overlay data exists, the first selector (2) that selects the data having a value opposite to the value of the overlay data; A second comparator (3) that compares the overlay data of the line with the image data, and the data and the image data having a value opposite to the value of the overlay data are received, and according to the comparison result of the second comparator (3), Select image data when overlay data does not exist, overlay when overlay data exists Interpolation for interpolating image data by receiving output data from the second selector (4) that selects data having a value opposite to the data value and the first selector (2) and the second selector (4) Means (5)
The pixel enlargement means (6) for enlarging the overlay data of the first line, the output of the interpolation means (5) and the value data equal to the overlay data are received, and the overlay data is output from the pixel enlargement means (6). And a third selector (8) for outputting the data having the same value as the overlay data when outputting the data and outputting the data from the interpolating means (5) when the overlay data is not output from the pixel enlarging means (6). An image enlargement processing circuit characterized by the above.