JP2896175B2 - Angle of view converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an improvement in an angle-of-view converter that scan-converts a still image signal transmitted by a specific system into another system.

(Prior Art) As is well known, for example, in order to scan-convert a 525-line, 60-field image signal represented by the NTSC system into a 625-line, 50-field image signal represented by the PAL or SECOM system. As shown in FIG. 4, the conventional angle-of-view converter converts an image signal supplied to an input terminal 11 into three types of interpolation signals, a time direction interpolation filter 12, a vertical direction interpolation filter 13, and a horizontal direction interpolation filter 14. Scan conversion is performed through a filter, and extracted from an output terminal 15.

However, such a conventional angle-of-view converter is used only for business use because the circuit scale of each of the interpolation filters 12 to 14 is large and economically disadvantageous. The problem that it cannot be done arises.

(Problems to be Solved by the Invention) As described above, the conventional angle-of-view conversion apparatus has a problem that the circuit scale is large and economically disadvantageous and cannot be used for consumer use.

Therefore, the present invention has been made in view of the above circumstances, and it is possible to scan-convert a still image signal transmitted in a specific system to another system with a simple configuration, which is economically advantageous and is suitable for consumer use. It is an object of the present invention to provide a very good angle-of-view conversion device suitable for the following.

[Structure of the Invention] (Means for Solving the Problems) The angle-of-view converter according to the present invention converts an n-line still image signal of a system in which one screen is composed of n lines into m (m> m).
n) It is intended to perform scan conversion to a line-based still image signal. Then, the picture part excluding the synchronous part of the n-line system still image signal is time-axis-compressed only in the horizontal direction, and is output in the picture part excluding the synchronous part of the m-line display screen. A frame signal is inserted into a picture portion other than the synchronous portion of the m-line display screen other than the portion, and the horizontal sampling frequency of the m-line display screen is changed to adjust the aspect ratio. .

Further, the angle-of-view conversion apparatus according to the present invention converts an n-line-based still image signal that composes one screen with n lines into m (m <m <
n) It is intended to perform scan conversion to a line-based still image signal. Then, signals of the number of lines and the number of samples corresponding to the picture portion excluding the synchronization portion of the m-line still image signal are extracted from the picture portion corresponding to the center portion of the screen excluding the synchronization portion of the n-line still image signal, and are horizontally extracted. The time axis is extended only in the direction and output to the picture portion excluding the synchronous portion of the m-line display screen, and the picture portion excluding the synchronous portion of the n-line still image signal other than the time-axis extended picture portion is removed.
The aspect ratio is adjusted by changing the sampling frequency in the horizontal direction of the m-line display screen.

(Operation) According to the above-described configuration, the n-line still image signal need only be subjected to time axis compression or expansion only in the horizontal direction. It can be scan converted to other formats, which is economically advantageous and suitable for consumer use.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example in which the 525-line still image signal shown in FIG. 1A is scan-converted into a 625-line still image signal shown in FIG. 1B. That is, the picture portion A excluding the synchronization section B of the 525-line still image signal [4f sc (fsc; color carrier frequency), 910fH525 (fH525; horizontal synchronization frequency of the 525-line still image signal)]
(491 lines in the vertical direction, 768 samples in the horizontal direction) are compressed in the horizontal direction on the time axis while the vertical direction is unchanged, and output as A '. Then, for example, a black level is inserted into a picture portion C 'other than the picture portion A' compressed on the time axis and excluding the synchronization section B 'of the 625-line still image signal in order to output as a frame. At the time of this scan conversion, the sampling frequency of one pixel, that is, one line, is set to 1083fH625 (fH625; 6).
By setting the horizontal synchronization frequency of a 25-line system still image signal), the aspect ratio can be maintained correctly. That is, if 525/625 = 910 / x = 0.84, x is approximately 1083, and as a result,
The screen reduced to 84% of the whole image is displayed on a 625-line monitor.

FIG. 2 shows an example in which the 625-line still image signal shown in FIG. 7A is scan-converted into the 525-line still image signal shown in FIG. That is, a picture portion A of 768 samples in the horizontal direction is output in 491 lines in the vertical direction from the picture portion excluding the synchronization section B of the still image signal of the 625 line system (4fsc, 1135fH625), and the time axis is extended only in the horizontal direction. Then, it applies to the portion of A 'except for the synchronous portion B' in the 525 line system. The remaining picture portion C is removed. In this scan conversion, by setting the sampling frequency of one pixel, that is, one line, to 953fH525, the aspect ratio can be correctly maintained. That is, if 625/525 = 1135 / x = 1.19, x becomes approximately 953, and as a result,
The screen enlarged to 1.2 times the entire size is displayed on a 525 line monitor.

FIG. 3 shows a specific configuration for executing the above operation. That is, in the figure, reference numeral 16 denotes a still image signal output device, which reproduces a recording medium on which a still image signal is recorded, such as an IC card, and outputs a still image signal. The still image signal output from the still image signal output device 16 is composed of a luminance signal Y and color difference signals RY and BY. The luminance signal Y and the color difference signal R-
Y and BY are subjected to predetermined signal processing such as band expansion in a signal processing circuit 17 and then supplied to a frame signal insertion / removal circuit 18. In the case of the scan conversion shown in FIG. 1, the frame signal insertion / removal circuit 18 provides a synchronous section B 'of the 625-line still image signal.
For example, a black level frame signal is generated and inserted into the picture portion C 'excluding the above, and in the case of the scan conversion shown in FIG. 2, the action of removing the picture portion C from the 625-line still image signal is performed. .

The luminance signal Y and the color difference signals RY and BY output from the frame signal insertion and removal circuit 18 are
Are converted into color signals R, G, and B, and output to, for example, a monitor (not shown) for image display. Further, the luminance signal Y and the color difference signals RY, B output from the frame signal
-Y is converted by the encoder 20 into a form corresponding to each system such as PAL, SECOM or NTSC, and output as a luminance signal Y and a chrominance signal C. In this case, the output luminance signal Y and chrominance signal C are added by the adding circuit 21 and can be obtained in the form of Y + C.

The still image signal output device 16, the signal processing circuit 17,
The frame signal insertion and removal circuit 18, the inverse matrix circuit 19, and the encoder 20 are driven based on a synchronization signal and a timing signal output from the timing generation circuit 22.

According to the configuration as in the above embodiment, the 525 or 625-line still image signal need only be subjected to time-axis compression or expansion only in the horizontal direction, so that scan conversion can be performed with a simple configuration, which is economically advantageous. It is suitable for consumer use.

It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the scope of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, a still image signal transmitted by a specific method can be scan-converted to another method with a simple configuration, and is economically advantageous and It is possible to provide a very good angle-of-view conversion device suitable for use.

[Brief description of the drawings]

1 and 2 are diagrams for explaining an embodiment of an angle-of-view conversion apparatus according to the present invention. FIG. 3 is a block diagram showing a specific configuration for realizing the embodiment. FIG. 4 is a block diagram showing a conventional angle-of-view converter. 11 ... input terminal, 12 ... time direction interpolation filter, 13 ...
Vertical interpolation filter, 14 ... Horizontal interpolation filter,
15 ... output terminal, 16 ... still image signal output device, 17 ...
Signal processing circuit, 18 Frame signal insertion and removal circuit, 19 Inverted matrix circuit, 20 Encoder, 21 Addition circuit, 22
... Timing generation circuit.

Claims (2)

(57) [Claims] 1. An angle-of-view conversion apparatus for scan-converting an n-line still image signal of a type in which one screen is composed of n lines into an m (m> n) line still image signal. The picture portion excluding the synchronous portion of the signal is time-axis-compressed only in the horizontal direction and output into the picture portion excluding the synchronous portion of the m-line display screen, and the m-lines other than the time-axis-compressed picture portion are output. A frame signal is inserted into a picture portion excluding a synchronous portion of the system display screen, and the aspect ratio is adjusted by changing a horizontal sampling frequency of the m-line system display screen. Angle of view converter. 2. An angle-of-view conversion apparatus for scan-converting an n-line still image signal that forms one screen with n lines into an m (m <n) -line still image signal. From the picture part corresponding to the center of the screen excluding the synchronization part, the signals of the number of lines and the number of samples corresponding to the picture part excluding the synchronization part of the m-line still image signal are extracted, and the time axis is expanded only in the horizontal direction. It outputs to the picture part except the synchronous part of the line system display screen, removes the picture part except the synchronous part of the n-line still image signal other than the picture part extended in the time axis, and removes the horizontal part of the m-line display screen. An angle-of-view conversion apparatus characterized in that an aspect ratio is adjusted by changing a sampling frequency in a direction.