“Photometric Camera Calibration: Precise, Labless, and Automated with AutoLum” by Olczak and Tumblin
Conference:
Type:
Entry Number: 78
Title:
- Photometric Camera Calibration: Precise, Labless, and Automated with AutoLum
Presenter(s)/Author(s):
Abstract:
Even cheap camera phones can sense finer changes in luminance than the human visual system (0:2 – :5% steps vs. 1 – 2% JND), but noise and poor calibration limits their abilities to precisely measure light. This poster describes “AutoLum”, our fully automatic, software-only method that finds a camera’s photometric calibration, its “numbers-to-light amounts” table, with precision well beyond the camera’s own quantization levels. This table captures each quantization step and reveals correctable non-uniformities that allow more accurate results for almost any graphics or vision task that relies on pixel-by-pixel light estimates. These include HDR light probes, environment maps, estimates of material transparency and translucency, BRDF and BTF, or any 3D scanning method that relies on “shape from shading”. As shown in (Fig. 1), our method reduced angular errors in photometric stereo by 10x.
References:
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