Color sample interpolation

• US 6,697,110 B1
• Filed: 07/15/1998
• Issued: 02/24/2004
• Est. Priority Date: 07/15/1997
• Status: Expired due to Term

• Current Assignee: ST-Ericcson SA (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Jaspers, Cornelis A. M., Hostiou, Eric, Delage, Eric
• Primary Examiner(s): MOE, AUNG SOE
• Application Number:
  US09/116,323
• Time in Patent Office: 2,050 Days
• Field of Search: 348/272, 348/273, 348/274, 348/275, 348/277, 348/280, 348/268, 348/242, 348/675, 348/222.1, 348/223.1, 348/225.1, 348/228.1, 382/162, 382/163, 382/167, 382/312
• US Class Current: 348/272
• CPC Class Codes: G06T 3/4007 based on interpolation, e.g. bilinear interpolation image demosaicing G06T3/4015; edge-driven or edge-based scaling G06T3/403
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns
• CPC Class Codes: H04N 2209/046 Colour interpolation to calculate the missing colour values
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements

Abstract

In a method of interpolating a color sample in a signal (RGBin) having alternately colored samples, the missing color sample is interpolated in dependence upon neighboring color samples (G1, G2, G3, G4) of the same color (G) as the color sample to be interpolated, and a differently colored sample (R/B) from the same location as the color sample to be interpolated.

Claims

1. A method of interpolating a color sample in a signal having alternately colored samples, the method comprising the steps:

providing neighboring color samples of the same color as the color sample to be interpolated;

providing a single differently colored sample from the same location as the color sample to be interpolated; and

interpolating the color sample to be interpolated in dependence upon the neighboring color samples of the same color and the single differently colored sample from the same location, to furnish an interpolated color sample,

wherein said interpolating step comprises the steps;

determining a horizontal average of horizontally neighboring color samples of the same color as the color sample to be interpolated;

determining a vertical average of vertically neighboring color samples of the same color as the color sample to be interpolated; and

furnishing a median of said horizontal average, said vertical average, and said differently colored sample from the same location.

2. A method of interpolating a color sample in a signal having alternately colored samples, the method comprising the steps:

providing neighboring color samples of the same color as the color sample to be interpolated;

providing a single differently colored sample from the same location as the color sample to be interpolated; and

interpolating the color sample to be interpolated in dependence upon the neighboring color samples of the same color and the single differently colored sample from the same location, to furnish an interpolated color sample,

wherein said interpolating step comprises the steps;

determining a horizontal average of horizontally neighboring color samples of the same color as the color sample to be interpolated;

determining a vertical average of vertically neighboring color samples of the same color as the color sample to be interpolated; and

calculating a weighed average of said horizontal average, said vertical average, in dependence upon said differently colored sample from the same location.

3. A method of interpolating a color sample in a signal having alternately colored samples, the method comprising the steps:

providing neighboring color samples of the same color as the color sample to be interpolated;

providing a differently colored sample from the same location as the color sample to be interpolated; and

interpolating the color sample to be interpolated in dependence upon the neighboring color samples of the same color and the differently colored sample from the same location, to furnish an interpolated color sample, said interpolating step comprising multiplying said differently colored sample from the same location by a white balance adjustment factor before said differently colored sample is taken into account,

wherein said method further comprises the step;

correcting the white balance adjustment factor by a matrix which Is an inverse of a color matrix for a camera providing the signal having alternately colored samples.