APPARATUS AND METHOD OF CONVERTING IMAGE SIGNAL

• US 20160286159A1
• Filed: 07/24/2015
• Published: 09/29/2016
• Est. Priority Date: 03/25/2015
• Status: Active Grant

• Current Assignee: Hanwha Vision Company Limited (Hanwha Corporation), Visionext Company Limited
• Original Assignee: Hanwha Techwin Co., Ltd. (Hanwha Corporation)
• Inventors: KIM, Seonggon
• Granted Patent: US 9,826,193 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 25/40 Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled
• CPC Class Codes: H04N 7/0102 involving the resampling of the incoming video signal

Abstract

Provided are an apparatus and method of converting a digital image signal, which is obtained through an image sensor comprising a plurality of pixels that are arranged in a matrix, into an analog image signal in order to transmit the analog image signal to a monitor device that outputs an image complying with a national television system committee (NTSC) standard or a phase-alternating line (PAL) standard. The method includes: generating a sample frequency based on the number of horizontal pixels of the digital image signal to comply with a horizontal scan period of the NTSC standard or the PAL standard; and converting image data of the horizontal pixels of the digital image signal into the analog image signal, according to the sample frequency.

Claims

1. A method of converting a digital image signal, which is obtained through an image sensor comprising a plurality of pixels that are arranged in a matrix, into an analog image signal in order to transmit the analog image signal to a monitor which is configured to output an image complying with a national television system committee (NTSC) standard or a phase-alternating line (PAL) standard, the method comprising:

generating a sample frequency by dividing a number of horizontal pixels of the digital image signal by a horizontal scan period of the NTSC standard or the PAL standard; and

converting image data of the horizontal pixels of the digital image signal into the analog image signal, according to the sample frequency.

2. The method of claim 1, further comprising changing a number of horizontal scan lines of the digital image signal to comply with a vertical resolution of the NTSC standard or the PAL standard.

3. The method of claim 1, wherein the image sensor is a complementary metal-oxide-semiconductor (CMOS) image sensor.

4. The method of claim 1, wherein the horizontal scan period according to the NTSC standard is 63.556 μ

s.

5. The method of claim 4, wherein in the number of horizontal pixels, a number of effective horizontal pixels is 1320,

wherein the horizontal scan period comprises an effective horizontal scan period of 53.333 μ

s, and

wherein the sample frequency is generated at 24.75 MHz.

6. The method of claim 4, wherein in the number of horizontal pixels, a number of effective horizontal pixels is 1200 and the number of dummy horizontal pixels is 230,

wherein the horizontal scan period comprises an effective horizontal scan period of 53.333 μ

s, and

wherein the sample frequency is generated at 22.5 MHz.

7. The method of claim 1, wherein the horizontal scan period according to the PAL standard is 64 μ

s.

8. The method of claim 7, wherein in the number of horizontal pixels, a number of effective horizontal pixels is 1200 and the number of dummy horizontal pixels is 240,

wherein the horizontal scan period comprises an effective horizontal scan period of 53.333 μ

s, and

wherein the sample frequency is generated at 22.5 MHz.

9. The method of claim 1, wherein the sample frequency is in proportion to a resolution of the analog image signal.

10. An apparatus for converting a digital image signal, which is obtained through an image sensor comprising a plurality of pixels that are arranged in a matrix, into an analog image signal in order to transmit the analog image signal to a monitor which is configured to output an image complying with a national television system committee (NTSC) standard or a phase-alternating line (PAL) standard, the apparatus comprising:

a receiver configured to receive the digital image signal;

a controller configured to generate a sample frequency by dividing a number of horizontal pixels of the digital image signal by a horizontal scan period of the NTSC standard or the PAL standard, and convert image data of the horizontal pixels of the digital image signal into the analog image signal according to the sample frequency; and

a transmitter configured to transmit the analog image signal to the monitor.

11. The apparatus of claim 10, wherein the controller is further configured to change a number of horizontal scan lines of the digital image signal to comply with a vertical resolution of the NTSC standard or the PAL standard.

12. The apparatus of claim 10, wherein the image sensor is a complementary metal-oxide-semiconductor (CMOS) image sensor.

13. The apparatus of claim 10, wherein the horizontal scan period according to the NTSC standard is 63.556 μ

s.

14. The apparatus of claim 13, wherein in the number of horizontal pixels, a number of effective horizontal pixels is 1320,

wherein the horizontal scan period comprises an effective horizontal scan period of 53.333 μ

s, and

wherein the sample frequency is generated at 24.75 MHz.

15. The apparatus of claim 13, wherein in the number of horizontal pixels of the digital image signal, a number of effective horizontal pixels is 1200,

wherein the horizontal scan period comprises an effective horizontal scan period of 53.333 μ

s, and

wherein the controller is configured to generate the sample frequency at 22.5 MHz.

16. The apparatus of claim 10, wherein the horizontal scan period according to the PAL standard is 64 μ

s.

17. The apparatus of claim 16, wherein in the number of horizontal pixels, a number of effective horizontal pixels is 1200 and the number of dummy horizontal pixels is 240,

wherein the horizontal scan period comprises an effective horizontal scan period of 53.333 μ

s, and

wherein the sample frequency is generated at 22.5 MHz.

18. The apparatus of claim 10, further comprising:

a video amplifier configured to amplify the analog image signal; and

a low-pass filter configured to pass through the amplified analog image signal and having a cutoff frequency of 11.25 MHz.

19. The apparatus of claim 10, further comprising a storage storing information about the number of horizontal pixels of the digital image signal to comply with a horizontal scan period of the NTSC standard or the PAL standard.