Method and apparatus for controlling a camera module to compensate for the color spectrum of a white led

A method of taking a picture with an electronic device, the electronic device having a storage containing a white balance patch, a flash source, and a camera module, the camera module having an image scanning element and a pre-determined white-balance routine that includes an initial limit region of a chromaticity chart, the initial limit region of the chromaticity chart overlying a portion of a blackbody radiation curve, the flash source having an optical spectrum lying outside the initial limit region of the chromaticity chart, the camera module being operable in an ambient light mode in which the image scanning element is controlled to capture and white-balance a succession of images, and in an artificial light source mode in which the image scanning element is controlled to capture and white-balance a single image, the method comprising:

• providing the white-balance patch to the camera module;
• modifying the initial limit region of the white-balance routine in accordance with the white-balance patch to obtain a modified limit region, the modified limit region including at least a portion of the flash source optical spectrum;
• receiving at the camera module, color coordinates of a first point of the chromaticity chart, the first point being outside the initial limit region and inside the modified limit region, the first point being used by the white-balance routine to define a reference white region, the reference white region excluding any portion of the black body radiation curve;
• energizing the flash source;
• and
• operating the camera module in the ambient light mode.

A method of making a camera module compatible with a flash source, the camera module having a pre-determined white-balance routine that includes an initial limit region of a chromaticity chart, the initial limit region of the chromaticity chart overlying a portion of a blackbody radiation curve, the flash source having an optical spectrum lying outside the initial limit region of the chromaticity chart, the camera module being operable in an ambient light mode in which the image scanning element is controlled to capture and white-balance a succession of images, and in an artificial light source mode in which the image scanning element is controlled to capture and white-balance a single image, the method comprising, at the camera module:

• modifying the initial limit region of the white-balance routine in accordance with at least one input value to obtain a modified limit region, the modified limit region including at least a portion of the flash source optical spectrum;
• receiving color coordinates of a first point of the chromaticity chart, the first point being outside the initial limit region and inside the modified limit region, the first point being used by the white-balance routine to define a reference white region, the reference white region excluding any portion of the black body radiation curve;
• and
• receiving an indication to operate in the ambient light mode.