Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera

William J. Dallas, Hans Roehrig, Elizabeth A Krupinski

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

We have combined a CMOS color camera with special software to compose a multi-functional image-quality analysis instrument. It functions as a colorimeter as well as measuring modulation transfer functions (MTF) and noise power spectra (NPS). It is presently being expanded to examine fixed-pattern noise and temporal noise. The CMOS camera has 9 μm square pixels and a pixel matrix of 2268 × 1512 × 3. The camera uses a sensor that has co-located pixels for all three primary colors. We have imaged sections of both a color and a monochrome LCD monitor onto the camera sensor with LCD-pixel-size to camera-pixel-size ratios of both 12:1 and 17.6:1. When used as an imaging colorimeter, each camera pixel is calibrated to provide CIE color coordinates and tristimulus values. This capability permits the camera to simultaneously determine chromaticity in different locations on the LCD display. After the color calibration with a CS-200 colorimeter the color coordinates of the display's primaries determined from the camera's luminance response are very close to those found from the CS-200. Only the color coordinates of the display's white point were in error. For calculating the MTF a vertical or horizontal line is displayed on the monitor. The captured image is color-matrix preprocessed, Fourier transformed then post-processed. For NPS, a uniform image is displayed on the monitor. Again, the image is pre-processed, transformed and processed. Our measurements show that the horizontal MTF's of both displays have a larger negative slope than that of the vertical MTF's. This behavior indicates that the horizontal MTF's are poorer than the vertical MTF's. However the modulations at the Nyquist frequency seem lower for the color LCD than for the monochrome LCD. The spatial noise of the color display in both directions is larger than that of the monochrome display. Attempts were also made to analyze the total noise in terms of spatial and temporal noise by applying subtractions of images taken at exactly the same exposure. Temporal noise seems to be significantly lower than spatial noise.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Volume6707
DOIs
StatePublished - 2007
EventPenetrating Radiation Systems and Applications VIII - San Diego, CA, United States
Duration: Aug 29 2007Aug 30 2007

Other

OtherPenetrating Radiation Systems and Applications VIII
CountryUnited States
CitySan Diego, CA
Period8/29/078/30/07

Fingerprint

Liquid crystal displays
Image quality
CMOS
Cameras
cameras
Color
color
modulation transfer function
Display devices
Pixels
pixels
Colorimeters
monitors
Optical transfer function
noise spectra
Power spectrum
power spectra
Nyquist frequencies
sensors
Sensors

Keywords

  • Color LCD
  • Colorimeter
  • Foveon camera
  • Image quality control
  • Imaging colorimeter
  • MTF
  • NPS

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Dallas, W. J., Roehrig, H., & Krupinski, E. A. (2007). Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 6707). [67070U] https://doi.org/10.1117/12.740250

Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera. / Dallas, William J.; Roehrig, Hans; Krupinski, Elizabeth A.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6707 2007. 67070U.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Dallas, WJ, Roehrig, H & Krupinski, EA 2007, Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 6707, 67070U, Penetrating Radiation Systems and Applications VIII, San Diego, CA, United States, 8/29/07. https://doi.org/10.1117/12.740250
Dallas WJ, Roehrig H, Krupinski EA. Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6707. 2007. 67070U https://doi.org/10.1117/12.740250
Dallas, William J. ; Roehrig, Hans ; Krupinski, Elizabeth A. / Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 6707 2007.
@inproceedings{89354122314445fd86a0ef9d3dd758cf,
title = "Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera",
abstract = "We have combined a CMOS color camera with special software to compose a multi-functional image-quality analysis instrument. It functions as a colorimeter as well as measuring modulation transfer functions (MTF) and noise power spectra (NPS). It is presently being expanded to examine fixed-pattern noise and temporal noise. The CMOS camera has 9 μm square pixels and a pixel matrix of 2268 × 1512 × 3. The camera uses a sensor that has co-located pixels for all three primary colors. We have imaged sections of both a color and a monochrome LCD monitor onto the camera sensor with LCD-pixel-size to camera-pixel-size ratios of both 12:1 and 17.6:1. When used as an imaging colorimeter, each camera pixel is calibrated to provide CIE color coordinates and tristimulus values. This capability permits the camera to simultaneously determine chromaticity in different locations on the LCD display. After the color calibration with a CS-200 colorimeter the color coordinates of the display's primaries determined from the camera's luminance response are very close to those found from the CS-200. Only the color coordinates of the display's white point were in error. For calculating the MTF a vertical or horizontal line is displayed on the monitor. The captured image is color-matrix preprocessed, Fourier transformed then post-processed. For NPS, a uniform image is displayed on the monitor. Again, the image is pre-processed, transformed and processed. Our measurements show that the horizontal MTF's of both displays have a larger negative slope than that of the vertical MTF's. This behavior indicates that the horizontal MTF's are poorer than the vertical MTF's. However the modulations at the Nyquist frequency seem lower for the color LCD than for the monochrome LCD. The spatial noise of the color display in both directions is larger than that of the monochrome display. Attempts were also made to analyze the total noise in terms of spatial and temporal noise by applying subtractions of images taken at exactly the same exposure. Temporal noise seems to be significantly lower than spatial noise.",
keywords = "Color LCD, Colorimeter, Foveon camera, Image quality control, Imaging colorimeter, MTF, NPS",
author = "Dallas, {William J.} and Hans Roehrig and Krupinski, {Elizabeth A}",
year = "2007",
doi = "10.1117/12.740250",
language = "English (US)",
isbn = "9780819468550",
volume = "6707",
booktitle = "Proceedings of SPIE - The International Society for Optical Engineering",

}

TY - GEN

T1 - Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera

AU - Dallas, William J.

AU - Roehrig, Hans

AU - Krupinski, Elizabeth A

PY - 2007

Y1 - 2007

N2 - We have combined a CMOS color camera with special software to compose a multi-functional image-quality analysis instrument. It functions as a colorimeter as well as measuring modulation transfer functions (MTF) and noise power spectra (NPS). It is presently being expanded to examine fixed-pattern noise and temporal noise. The CMOS camera has 9 μm square pixels and a pixel matrix of 2268 × 1512 × 3. The camera uses a sensor that has co-located pixels for all three primary colors. We have imaged sections of both a color and a monochrome LCD monitor onto the camera sensor with LCD-pixel-size to camera-pixel-size ratios of both 12:1 and 17.6:1. When used as an imaging colorimeter, each camera pixel is calibrated to provide CIE color coordinates and tristimulus values. This capability permits the camera to simultaneously determine chromaticity in different locations on the LCD display. After the color calibration with a CS-200 colorimeter the color coordinates of the display's primaries determined from the camera's luminance response are very close to those found from the CS-200. Only the color coordinates of the display's white point were in error. For calculating the MTF a vertical or horizontal line is displayed on the monitor. The captured image is color-matrix preprocessed, Fourier transformed then post-processed. For NPS, a uniform image is displayed on the monitor. Again, the image is pre-processed, transformed and processed. Our measurements show that the horizontal MTF's of both displays have a larger negative slope than that of the vertical MTF's. This behavior indicates that the horizontal MTF's are poorer than the vertical MTF's. However the modulations at the Nyquist frequency seem lower for the color LCD than for the monochrome LCD. The spatial noise of the color display in both directions is larger than that of the monochrome display. Attempts were also made to analyze the total noise in terms of spatial and temporal noise by applying subtractions of images taken at exactly the same exposure. Temporal noise seems to be significantly lower than spatial noise.

AB - We have combined a CMOS color camera with special software to compose a multi-functional image-quality analysis instrument. It functions as a colorimeter as well as measuring modulation transfer functions (MTF) and noise power spectra (NPS). It is presently being expanded to examine fixed-pattern noise and temporal noise. The CMOS camera has 9 μm square pixels and a pixel matrix of 2268 × 1512 × 3. The camera uses a sensor that has co-located pixels for all three primary colors. We have imaged sections of both a color and a monochrome LCD monitor onto the camera sensor with LCD-pixel-size to camera-pixel-size ratios of both 12:1 and 17.6:1. When used as an imaging colorimeter, each camera pixel is calibrated to provide CIE color coordinates and tristimulus values. This capability permits the camera to simultaneously determine chromaticity in different locations on the LCD display. After the color calibration with a CS-200 colorimeter the color coordinates of the display's primaries determined from the camera's luminance response are very close to those found from the CS-200. Only the color coordinates of the display's white point were in error. For calculating the MTF a vertical or horizontal line is displayed on the monitor. The captured image is color-matrix preprocessed, Fourier transformed then post-processed. For NPS, a uniform image is displayed on the monitor. Again, the image is pre-processed, transformed and processed. Our measurements show that the horizontal MTF's of both displays have a larger negative slope than that of the vertical MTF's. This behavior indicates that the horizontal MTF's are poorer than the vertical MTF's. However the modulations at the Nyquist frequency seem lower for the color LCD than for the monochrome LCD. The spatial noise of the color display in both directions is larger than that of the monochrome display. Attempts were also made to analyze the total noise in terms of spatial and temporal noise by applying subtractions of images taken at exactly the same exposure. Temporal noise seems to be significantly lower than spatial noise.

KW - Color LCD

KW - Colorimeter

KW - Foveon camera

KW - Image quality control

KW - Imaging colorimeter

KW - MTF

KW - NPS

UR - http://www.scopus.com/inward/record.url?scp=42149136296&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=42149136296&partnerID=8YFLogxK

U2 - 10.1117/12.740250

DO - 10.1117/12.740250

M3 - Conference contribution

AN - SCOPUS:42149136296

SN - 9780819468550

VL - 6707

BT - Proceedings of SPIE - The International Society for Optical Engineering

ER -