JP2001045443A - Television image data generator and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To output NTSC image data and PAL image data without deteriorating the image. SOLUTION: Line image data are interpolated to image data outputted from an NTSC image pickup element 2 and a memory 3 outputs image data with the number of lines suitable for display onto a PAL display device. The image data outputted from the memory 3 are given to a line interleaving circuit 5 and a PAL encoder 6. The line interleaving circuit 5 interleaves the interpolated line image data and outputs the result. The PAL encoder 6 converts the image data into a PAL signal and outputs it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an apparatus and a method for generating television image data.

[0002]

BACKGROUND OF THE INVENTION Color television signal systems include N
TSC (National Television System Committee) system and PAL (Phase Alternation by Line color televisi)
on) method. One of the differences between the NTSC system and the PAL system is the difference in the number of horizontal scanning lines. In the NTSC system, the number of horizontal scanning lines (the number of lines) in one frame is 525, whereas in the PAL system, the number of horizontal scanning lines is 625.

When an NTSC image signal is applied to a PAL display device, no image is displayed on the display screen because the number of horizontal scanning lines is smaller than that required for a PAL display device. An unrecognized area appears.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to enable image data representing the same image to be output as both NTSC image data and PAL image data.

A television image data generating apparatus according to the present invention outputs image data having a number of horizontal scanning lines suitable for displaying an image on an NTSC display device. Line image data interpolating the input image data, interpolating the line image data with the input image data, and generating and outputting image data having a number of horizontal scanning lines suitable for displaying an image on a PAL display device Means, a PAL television signal generating means for encoding the image data output from the line image data interpolating means to generate a PAL television signal, and the image data output from the line image data interpolating means. The line image data interpolated by the line image data interpolating means is thinned out, and a table for NTSC is used. Those having a line image data thinning means for outputting image data having a number of horizontal scanning lines suitable for image display on the device.

The method of generating television image data according to the present invention obtains image data having a number of horizontal scanning lines suitable for displaying an image on an NTSC display device, and interpolates the obtained image data with line image data. To generate image data having a number of horizontal scanning lines suitable for displaying an image on a PAL display device, encode the generated image data to generate a PAL television signal, and interpolate from the generated image data. Thinned line image data, N
This is to obtain image data having a number of horizontal scanning lines suitable for displaying an image on a display device for TSC.

Image data having a suitable number of horizontal scanning lines for a PAL display device obtained by interpolating line image data with image data having a number of horizontal scanning lines suitable for displaying an image on an NTSC display device Is given to the PAL display device, a PAL image is displayed on the PAL display device.
NTS obtained by thinning out line image data from image data having a suitable number of horizontal scanning lines for a PAL display device
When image data having a suitable number of horizontal scanning lines for the C display device is provided to the NTSC display device, an NTSC image is displayed on the NTSC display device.

According to the present invention, image data having a number of horizontal scanning lines suitable for displaying an image on an NTSC display device and image data having a number of horizontal scanning lines suitable for displaying an image on a PAL display device are provided. You can get both. NT
In each of the SC display device and the PAL display device, almost the same image is displayed on the entire display screen of the display device. In the PAL display device, an area where no image is displayed does not appear on a part of the display screen.

According to the present invention, the line image data to be thinned out from the image data having the number of horizontal scanning lines suitable for displaying the image on the PAL display device is provided in a number suitable for displaying the image on the NTSC display device. This is the same as the line image data interpolated when obtaining image data having a number of horizontal scanning lines suitable for image display on a PAL display device from image data having horizontal scanning lines. The same image data as the image data before interpolating the line image data can be obtained. As described above, since the thinned line image data is the interpolated line image data itself, it is possible to prevent deterioration of the image quality of the display image in the NTSC display device.

For image data having a number of horizontal scanning lines suitable for displaying an image on a PAL display device, a process of generating a PAL television signal and a process of thinning out line image data are performed. Since these processing times are almost the same, the same image is displayed almost simultaneously on the PAL display device and the NTSC display device.

In one embodiment, the interpolation of the line image data is performed by repeatedly outputting the line image data of a predetermined line in the input image data at a ratio of one line to five lines. Since the image represented by the line image data is evenly interpolated, a natural image is displayed on the PAL display device.

In another embodiment, the image data output means captures a subject and converts the image data representing the subject image obtained by the capturing into a horizontal scanning line number suitable for displaying an image on an NTSC display device. This is an imaging unit that outputs image data having scanning lines. Display and NTSC for NTSC
A subject image obtained by imaging can be displayed on both display devices.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing the electrical configuration of a digital camera. FIG. 2A shows an image represented by image data output from the NTSC image sensor 2, and FIG. 2B shows an image represented by image data output from the memory 3. 3A is an enlarged view of an upper left part of the image shown in FIG. 2A, and FIG. 3B is an enlarged view of an upper left part of the image shown in FIG. 2B. . 3A and 3B, the line numbers of the horizontal scanning lines are shown on the left side of the image.

The digital camera 1 includes an image sensor 2 for NTSC. The NTSC image sensor 2 has 640 pixels in the horizontal direction.
And 480 photoelectric conversion elements are arranged in the vertical direction (640 × 480). As shown in FIG. 2A, the NTSC imaging element 2 outputs image data having 480 horizontal scanning lines (lines) per frame.

The image data output from the NTSC image sensor 2 is temporarily stored in a memory 3.

Line image data is sequentially read from the memory 3 for each horizontal line.

The memory 3 is supplied with a line shift signal from the memory controller 4. When the line shift signal is applied from the memory controller 4 to the memory 3, the line of the line image data read from the memory 3 is shifted up, and the line image data of the next line is read from the memory 3.

In reading out line image data from the memory 3, line image data of the same line is read out at a rate of one line out of five lines. Then, Figure 3
From the memory 3 to which image data representing an image as shown in FIG. 3A is input, image data representing a line-interpolated image as shown in FIG. 3B is output (the interpolated line image is hatched). Emphasis).

More specifically, first line image data representing the image of the first line of the image temporarily stored in the memory 3 is read from the memory 3. After that, the memory
A line shift signal is output from the controller 4 and supplied to the memory 3. Then, the image data of the second line following the first line is read from the memory 3. Thereafter, a line shift signal is supplied from the memory controller 4 to the memory 3 again. The third line of image data is read from the memory 3.

The memory controller 4 temporarily stops outputting the line shift signal while reading the first line image data to the fifth line image data. line·
When the output of the shift signal is stopped, the line image data of the same line is read from the memory 3 again. The line image data of the same line is read twice,
Line interpolation is performed.

The output of the line shift signal is temporarily stopped at every reading interval of the line image data for five lines, so that line interpolation is performed at a ratio of one line to five lines.

In the image shown in FIG. 3B, the third line image data and the eighth line image data of the image data representing the image shown in FIG. Line interpolation (3A line, 8A line) has been performed on the image shown in FIG.

When the line interpolation is performed at a ratio of one line to five lines, the number of lines increases by 6/5 times. Therefore, the number of horizontal scanning lines of one frame of line image data output from the memory 3 is 576 lines. (480/5 × 6 = 576). The number of 576 horizontal scanning lines is determined by the PAL display device (eg, PA
(L television monitor) is close to the number of horizontal scanning lines on the display screen.

Image data having 576 horizontal scanning lines / frames output from the memory 3 is supplied to the line thinning circuit 5 and the PAL encoder 6, respectively.

The line thinning circuit 5 receives the image data output from the memory 3 and receives a thinning signal from the memory controller 4. The thinning signal controls the line thinning circuit 5 so that the line image data interpolated in the memory 3 is thinned out from the image data input to the line thinning circuit 5 and output.

Taking the images shown in FIGS. 3A and 3B as an example, based on the thinning signal supplied from the memory controller 4, the line thinning circuit 5 outputs the third image of the image shown in FIG. The line and the line image data of the 8Ath line are thinned out. As a result, image data representing the image shown in FIG. 3A is output from the line thinning circuit 5.

The image data output from the line thinning circuit 5 is supplied to the NTSC LCD 9. The LCD 9 for NTSC corresponds to the number of pixels of the image sensor 2 for NTSC.
It has 640 x 480 pixels. An image representing the subject image as shown in FIG. 2A is displayed on the entire display screen of the LCD 9 for NTSC.

The PAL encoder 6 converts the input image data into a PAL television signal, for example, by adding a synchronizing signal to a luminance signal included in the input image data and modulating the chrominance signal by a subcarrier. Output. The image data input to the PAL encoder 6 is
It is output from the PAL encoder 6 as an L-system television signal. The television signal output from the PAL encoder 6 is supplied to a PAL television signal output terminal 7.

The PAL television signal supplied to the PAL television signal output terminal 7 has 576 horizontal scanning lines per frame. The PAL television monitor 8 is suitable for a television signal having a horizontal scanning line number of 625 lines / frame, but the number of horizontal scanning lines displayed on the display screen is about 576 lines / frame (display screen). Above and below, there are horizontal scanning lines that are not displayed.) Therefore, according to a television signal having 576 horizontal scanning lines per frame,
A line-interpolated image is displayed on the entire display screen of the PAL television monitor 8. An image as shown in FIG. 2B is displayed on the entire display screen of the PAL television monitor 8.

The line image data is interpolated into image data having a number of horizontal scanning lines suitable for display on an NTSC display device, and image data having a number of horizontal scanning lines suitable for display on a PAL display device is once generated. Even if it does, the interpolated line image data is thinned out as it is, so that the image quality of the image displayed on the NTSC LCD 9 is prevented from deteriorating.

Further, since both the PAL encoder 6 and the line thinning circuit 5 can perform data processing in real time, the timing at which image signals are supplied to the PAL television monitor 8 and the NTSC LCD
9 is almost the same as the timing at which the image signal is supplied. An image based on the image data obtained by the NTSC imaging device 2 is displayed almost simultaneously on both the NTSC LCD 9 and the PAL television monitor 8.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an electrical configuration of a digital camera.

2A illustrates an example of an image represented by image data output from an NTSC image sensor, and FIG. 2B illustrates an example of an image represented by image data output from a memory.

3 (A) is an enlarged view of the upper left portion of the image shown in FIG. 2 (A), and FIG. 3 (B) is an enlarged view of the upper left portion of the image shown in FIG. 2 (B). is there.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Digital camera 2 Image sensor for NTSC 3 Memory 4 Memory controller 5 Line thinning circuit 6 PAL encoder 7 PAL television signal output terminal 9 LCD for NTSC

Claims (4)

[Claims] 1. An image data output means for outputting image data having a number of horizontal scanning lines suitable for displaying an image on an NTSC display device, and image data output from the image data output means. A line image data interpolating unit for interpolating line image data into image data to generate and output image data having a number of horizontal scanning lines suitable for displaying an image on a PAL display device; PAL television signal generating means for encoding the output image data to generate a PAL television signal, and interpolating by the line image data interpolating means from the image data output from the line image data interpolating means. An image with the number of horizontal scanning lines suitable for displaying an image on an NTSC display device by thinning out line image data A television image data generating apparatus comprising: line image data thinning means for outputting image data. 2. The apparatus according to claim 1, wherein said line image data interpolating means repeatedly outputs line image data of a predetermined line out of the input image data at a ratio of one line to five lines. Television image data generation device. 3. The image data output means captures a subject and converts the image data representing the subject image obtained by the capture into image data having a number of horizontal scanning lines suitable for displaying an image on an NTSC display device. 3. The television image data generation device according to claim 1, wherein the television image data generation device is an imaging unit that outputs the image data. 4. An image display having a number of horizontal scanning lines suitable for displaying an image on an NTSC display device, interpolating the line image data with the obtained image data, and displaying an image on a PAL display device. Image data having a suitable number of horizontal scanning lines for the image data, encoding the generated image data to generate a PAL television signal, thinning out the interpolated line image data from the generated image data,
A method for generating television image data, wherein image data having a number of horizontal scanning lines suitable for displaying an image on an NTSC display device is obtained.