Apparatus and method for vertically extending an image in a television system

• US 5,793,433 A
• Filed: 12/29/1995
• Issued: 08/11/1998
• Est. Priority Date: 03/31/1995
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Min-Seung, Kim, Jeong-Hoon
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): Snow, Frank
• Application Number:
  US08/581,491
• Time in Patent Office: 956 Days
• Field of Search: 348/441, 348/445, 348/469, 348/722, 348/458, 348/556
• US Class Current: 348/445
• CPC Class Codes: H04N 7/0122 the input and the output signals having different aspect ratios
• CPC Class Codes: H04N 7/0135 involving interpolation processes interpolation-based image scaling G06T3/4007; interpolation for video coding H04N19/587, H04N19/59

Abstract

An apparatus and method for extending the height of an image to display a video signal having a 4:3 aspect ratio on a screen having a 16:9 aspect ratio. The apparatus includes: a field memory for storing pixel data of horizontal scanning lines of an input region which will be extended vertically, among the horizontal scanning lines of a field unit being inputted, and outputting the pixel data of the horizontal scanning lines of a region which will be extended vertically among the stored pixel data; line memories for sequentially inputting and delaying the pixel data outputted from the field memory by a horizontal scanning line unit, the number of the line memories corresponding to a vertical extension rate of the image; and a low-pass filtering and sub-sampling part for low-pass filtering and sub-sampling by respectively multiplying different filter coefficients having values determined by positions of new vertically extended horizontal scanning lines by the pixel data of the horizontal scanning lines which are each outputted with a different delay from the line memories and by adding the multiplied pixel data in correspondence with the positions of the new horizontal scanning lines, to thereby output the pixel data of the vertically extended horizontal scanning lines.

Claims

1. An apparatus for vertically extending an image in order to display an input video signal having said image in letter box format having an aspect ratio of 4:

3 on a screen having an aspect ratio of 16;

9, said apparatus comprising;

a field memory for storing pixel data of initial horizontal scanning lines of an input region which will be extended vertically, among said initial horizontal scanning lines of a field unit being inputted, and outputting said pixel data of said horizontal scanning lines of a region which will be extended vertically among said stored pixel data;

line memories for sequentially inputting and delaying said stored pixel data outputted from said field memory by units of said initial horizontal scanning lines, the number of said line memories corresponding to a vertical extension ratio of said image; and

low-pass filtering and sub-sampling means for low-pass filtering and su b-sampling by respectively multiplying filter coefficients, the value of the filter coefficients being determined by positions of new vertically extended horizontal scanning lines, by said pixel data of said initial horizontal scanning lines, each of said pixel data being delay-outputted with a different delay from said line memories, and by adding said multiplied pixel data in correspondence with said positions of said new horizontal scanning lines, to thereby output new pixel data of said new vertically extended horizontal scanning lines.

2. The apparatus as claimed in claim 1, wherein said low-pass filtering and sub-sampling means generates four of said new vertically extended horizontal scanning lines for each three of said initial horizontal scanning lines of said input video signal.

3. The apparatus as claimed in claim 2, wherein said low-pass filtering and sub-sampling means simultaneously performs a zero-insertion and said sub-sampling by not multiplying said filter coefficients by three pixel data having a zero value which are inserted between pixel data of said initial horizontal scanning lines outputted respectively from said line memories.

4. The apparatus as claimed in claim 1, wherein said low-pass filtering and sub-sampling means generates three of said new vertically extended horizontal scanning lines for two of said initial horizontal scanning lines of said input video signal.

5. The apparatus as claimed in claim 4, wherein said low-pass filtering and sub-sampling means simultaneously performs a zero-insertion and said sub-sampling by not multiplying said filter coefficients by two pixel data having a zero value which are inserted between pixel data of said initial horizontal scanning lines outputted respectively from said line memories.

6. A method for extending height of an image in order to display a video signal having said image in letter box format having an aspect ratio of 4:

3 on a screen having an aspect ratio of 16;

9, said method comprising the steps of;

inserting pixel data having zero value, the number of inserted pixel data being set in accordance with a vertical extension ratio, between pixels of initial horizontal scanning lines of an input video signal, thereby producing a zero-inserted signal; and

generating new horizontal scanning lines for use in vertically extending said image by multiplying filter coefficients, the value of the filter coefficients being determined by a position of a corresponding one of the new horizontal scanning lines being generated, by every n^th pixel of said zero-inserted signal, wherein n is one more than the number of said zero value pixel data inserted between each of said pixels of said initial horizontal scanning lines, thereby producing a spectrum elimination signal, and then sub-sampling the spectrum elimination signal in accordance with said vertical extension ratio.

7. The method as claimed in claim 6, wherein the step of inserting pixel data having zero value is performed simultaneously with said sub-sampling by not multiplying said filter coefficients by the pixel data having a zero value.

8. A method for vertically extending an image in order to display a video signal having said image of a letter box format having a 4:

3 aspect ratio on a screen having 16;

9 aspect ratio, said method comprising the steps of;

inserting three pixel data having zero value between pixels of horizontal scanning lines of an input video signal, thereby producing a zero-inserted signal; and

generating new horizontal scanning lines for use in vertically extending said image by multiplying filter coefficients, the value of the filter coefficients being determined by a position of a corresponding one of the new horizontal scanning lines being generated, by every fourth pixel of said zero-inserted signal, thereby producing a spectrum elimination signal, and then sub-sampling the spectrum elimination signal by a 3;

1 rate in a vertical direction.

9. The method as claimed in claim 8, wherein the step of inserting pixel data having zero value is performed simultaneously with said sub-sampling by not multiplying said filter coefficients by the pixel data having a zero value.

10. A method for vertically extending an image in order to display a video signal having said image of a letter box format having a 4:

3 aspect ratio on a screen having a 16;

9 aspect ratio, said method comprising the steps of;

inserting two pixel data having zero value between pixels of horizontal scanning lines of an input video signal, thereby producing a zero-inserted signal; and

generating new horizontal scanning lines for use in vertically extending said image by multiplying filter coefficients, the value of the filter coefficients being determined by a position of a corresponding one of the new horizontal scanning lines being generated, by every third pixel of said zero-inserted signal, thereby producing a spectrum elimination signal, and then sub-sampling the spectrum elimination signal by a 2;

1 rate in a vertical direction.

11. The method as claimed in claim 10, wherein the step of inserting pixel data having zero value is performed simultaneously with said sub-sampling by not multiplying said filter coefficients by the pixel data having a zero value.