US 5,333,055 AGranted

Video camera circuit for processing image signals from an image pickup device having a mosaic color filter

AssigneeSanyo Electric Co., Ltd.

InventorsHaruhiko Murata, Yukio Mori, Akihiro Maenaka, Masao Takuma, Kiyotada Kawakami, Toru Yamamoto, Toru Asaeda

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Abstract

A video camera circuit for processing an image signal from an image pickup device having a mosaic color filter comprises a field memroy control circuit for reading out a predetermined line of signal (CCD output data) from a field memory when the position of vertical interpolation has changed, first, second and third line memories for storing the signal from the field memory, a line memory control circuit for controlling signal writing in and reading out from the line memories to concurrently retrieve three lines of signal, a vertical interpolation block for preparing a signal at the position of interpolation based on the four lines of signal, and a Y/C separation block for separating a luminance signal and color difference signals from the signal at the position of interpolation.

Claims11

Dependent claims

In a video camera comprising an image pickup device having a mosaic color filter and a field memory for storing an image output from the pickup device on conversion to a CCD output digital signal, the camera being adapted to vertically interpolate said CCD output digital signal as read out from the field memory in corresponding relation with an image area to be processed for zooming and to produce a luminance signal and color difference signals for each of horizontal scan lines for forming a zoomed image, a video camera circuit comprising:

a field memory control circuit for reading out from the field memory said CCD output digital signal of the lower-most of four consecutive horizontal scan lines on a screen of a monitor presenting the image, said scan lines consisting of two lines above and two lines below a new position of vertical interpolation when the position of interpolation has changed,
first, second and third line memories connected to an output terminal of the field memory for storing first, second and third digital signals of three horizontal scan lines, respectively, from the field memory each from line to line,
a line memory control circuit connected between said field memory control circuit and said first, second and third line memories for controlling writing in and reading out of data from the first, second and third line memories to concurrently retrieve said first, second and third digital signals of the three of the four horizontal scan lines,
a vertical interpolation circuit connected to the four horizontal scan lines for preparing an interpolated digital signal on a horizontal scan line at the position of interpolation based on said first, second, third and CCD output digital signals, respectively, of the four horizontal scan lines, said vertical interpolation circuit including a plurality of filters used in preparing said interpolated digital signal, and
a Y/C separation circuit connected to an output of two of said filters for separating a luminance signal and color difference signals from said interpolated digital signal at the interpolation position to output the separated signals.

2 more elements

A video camera circuit for processing an image signal from an image pickup device having a mosaic color filter, comprising:

means operable based on the image signal on a plurality of horizontal scan lines consecutive with respect to a vertical direction for detecting a linear differential signal of a luminance signal contained in the image signal with respect to the vertical direction,
means for preparing a control signal for suppressing a false color signal produced with respect to the vertical direction and attributable to the color filter, upon the absolute value of the linear differential signal exceeding a predetermined value, and
means for suppressing a color signal contained in the image signal in accordance with the control signal.

A video camera circuit for processing an image signal from an image pickup device having a mosaic color filter, the circuit comprising:

means for preparing from the image signal on a plurality of horizontal scan lines arranged in a vertical direction a linear differential signal and a quadratic differential signal of a luminance signal with respect to the vertical direction,
means for preparing a control signal for suppressing a false color signal produced with respect to the vertical direction and attributable to the color filter, upon the sum of the absolute value of the linear differential signal and the absolute value of the quadratic differential signal exceeding a predetermined value, and
means for suppressing a color signal contained in the image signal in accordance with the control signal.

Dependencies are inferred from the claim text.

Facts

Application: 08/021,473Filed 23 Feb 1993
Priority: JP 4-03607624 Feb 1992
Granted: 26 Jul 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H04N 23/843
For processing colour signals: demosaicing, e.g. interpolating colour pixel values
H04N 25/13
Arrangement of colour filter arrays [CFA]; Filter mosaics: characterised by the spectral characteristics of the filter elements
H04N 25/136
Based on four or more different wavelength filter elements: using complementary colours
H04N 2209/046
Using mosaic colour filter: colour interpolation to calculate the missing colour values