Electronic zooming circuit

• US 6,801,252 B1
• Filed: 12/29/1999
• Issued: 10/05/2004
• Est. Priority Date: 01/20/1999
• Status: Expired due to Term

• Current Assignee: Rakuten, Inc. (Rakuten Group, Inc.)
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Kurashige, Norio, Kawada, Shingo, Nishiyama, Hiroshi
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Rosendale, Matthew L
• Application Number:
  US09/474,104
• Time in Patent Office: 1,742 Days
• Field of Search: 348/240.99, 348/240.1, 348/240.2, 348/294, 348/295, 348/296, 348/312, 348/222.1, 382/298
• US Class Current: 348/240.2
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/69 Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

In a case that a zooming magnification is less than 2 times, the switch (SW) is connected to the terminal “a” and a zooming process in the horizontal direction is performed when reading out from the line memory (13) in conjunction with performing the zooming process in the vertical direction in the CCD (10). Further, in a case that the zooming magnification is more than 2 times, the switch (SW) is connected to the terminal “b” and the zooming process in the horizontal direction is performed with combining occasions when reading out from the memory (12) and reading out from the line memory (13) in conjunction with performing the zooming process in the horizontal direction when reading out from the memory (12).

Claims

1. An electronic zooming circuit for obtaining an enlarged image from an original image in which one field is formed by N lines by enlarging only an area within predetermined horizontal and vertical ranges of the original image, said electronic zooming circuit comprising:

a solid state image sensing device outputting a video signal of N lines in total within a period of one field by outputting repeatedly a video signal of lines, wherein a number of lines to be read out within the period of one field is arbitrarily designated between said N lines and M lines, which is smaller than said N lines;

a memory in which said video signal of N lines outputted from said solid state image sensing device is written without duplication and read out;

a line memory in which one line of said video signal outputted from either said solid state image sensing device or said memory is written and read out; and

an interpolation circuit for obtaining said enlarged image by interpolating said video signal read out from said line memory in the horizontal and vertical directions,

said electronic zooming circuit further comprising a first operation mode in which zooming magnification is less than N/M magnifications and a second operation mode in which said zooming magnification exceeds N/M magnifications,

said electronic zooming circuit is further characterized in that said interpolation circuit conducts an interpolation process in said first operation mode by sequentially supplying a video signal of some lines exceeding said M lines read out from said solid state image sensing device to said line memory without writing in said memory, and

that said interpolation circuit conducts an interpolation process in said second operation mode by sequentially writing a video signal of said M lines, which is read out from said solid state image sensing device and stored in said memory once, in said line memory, wherein some or all of said video signal of M lines once stored in said memory are read out from said memory.

2. The electronic zooming circuit in accordance with claim 1, wherein a value of said N/M is 2.

3. The electronic zooming circuit in accordance with claim 1, wherein a video signal within a predetermined vertical range corresponding to said zooming magnification in said video signal of M lines is read out from said memory in said second operation mode.