HP Labs Technical Reports

Digital Color Cameras - 2 - Spectral Response

Vora, Poorvi L.; Farrell, Joyce E.;Tietz, Jerome D.; Brainard, David H.

HPL-97-54

Keyword(s):digital cameras; color sensors; calibration; sensor estimation

Abstract: This report describes the spectral calibration of two digital color cameras, the Kodak DCS-200 and the Kodak DCS-420. We used previous work to model the output of the cameras in terms of the spectral sensitivities of the color sensors. We took measurements of the camera output for narrow-band spatially uniform scenes and used this data to estimate the sensor spectral sensitivities. The estimated spectral sensitivities were used to generate predicted RGB values which were compared to the measurements. The error between the predicted and measured values is a measure of the accuracy of the sensitivity estimates. For our estimates, this error is comparable to our estimates of the camera response variability. We also used the sensor estimates to predict the response of the DCS-200 to an independently acquired image. This prediction error was also small.

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