This paper introduces a calibration-based auto white balance method for digital still camera. The main idea is to detect white-points in an image accurately. White-Point Color Temperature Curve (WPCTC) is constructed from sensor calibration and is utilized to estimate white-point locations in a scene. Minimum Color Temperature Distance (MCTD) with a luminance threshold is defined to further locate white-points of an image exactly. Our proposed method is performed in RGB color space so it is suitable for digital still camera pipeline design. In our experiments, our approach is compared with other white balance methods and performs better in color consistency.