Method and apparatus of image dynamic response re-mapping and digital camera using the same

A method of image dynamic response re-mapping for receiving an original Bayer image data and performing the image dynamic response re-mapping on the original Bayer image data to generate modulated Bayer image data, the method comprising:

• a color coordinate transforming step for receiving the original Bayer image data and transforming the original Bayer image data into a new transformed image data on a new image coordinate system, wherein the quantity of the new transformed image data on the new image coordinate system is smaller than the data quantity of the original Bayer image data;
• a high gain generating step for receiving the new transformed image data and calculating a maximum gain from a high gain dynamic response distribution curve according to data of a to-be-processed pixel;
• a low gain generating step for receiving the new transformed image data and calculating a minimum gain from a low gain dynamic response distribution curve according to the data of the to-be-processed pixel;
• an image characteristic value generating step for receiving the new transformed image data, performing an image locality analysis on a neighboring image of the to-be-processed pixel on the new image coordinate system, and calculating a characteristic value of the neighboring image, which comprises an average illumination Δy, a illumination variability δy and a histogram of illumination;
• a weighting calculating step for generating a first weighting, which is inversely proportional to the average illumination Δy, and a second weighting, which is directly proportional to the illumination variability δy and relates to the histogram and the data of the to-be-processed pixel, according to the characteristic value;
• a modulated value calculating step for calculating a gain modulated value according the maximum gain, the minimum gain, the first weighting and the second weighting;
• and
• an image synthesizing step for receiving the original Bayer image data and the gain modulated value, and multiplying the original Bayer image data by the corresponding gain modulated value to generate the modulated Bayer image data.

A digital camera with an image dynamic response re-mapping function, the digital camera comprising:

• an image sensor for capturing a to-be-shot image and then transforming the to-be-shot image into an original Bayer image data;
• an image dynamic response re-mapping unit for receiving the original Bayer image data and modulating dynamic response of the original Bayer image data to generate modulated Bayer image data;
• an image processing unit for receiving the modulated Bayer image data and processing the modulated Bayer image data into processed image data;
• an image compressing unit for receiving the processed image data and compressing the processed image data into compressed image data;
• a storage unit for receiving and storing the compressed image data;
• and
• a display unit for receiving and displaying the processed image data, wherein the image dynamic response re-mapping unit comprises:
• a color coordinate transforming unit for receiving the original Bayer image data and transforming the original Bayer image data into new transformed image data on a new image coordinate system, the image data quantity of the new transformed image data on the new image coordinate system being smaller than the data quantity of the original Bayer image data;
• a high gain generator for receiving the new transformed image data and calculating a maximum gain from a high gain dynamic response distribution curve according to data of a to-be-processed pixel;
• a low gain generator for receiving the new transformed image data and calculating a minimum gain from a low gain dynamic response distribution curve according to the data of the to-be-processed pixel;
• an image characteristic value generator for receiving the new transformed image data, performing an image locality analysis on an neighboring image of the to-be-processed pixel on the new image coordinate system, and calculating a characteristic value of the neighboring image, which comprising an average illumination Δy, a illumination variability δy and a histogram;
• a weighting calculating unit for generating a first weighting and a second weighting according to the characteristic value, wherein the first weighting is inversely proportional to the average illumination Δy, and the second weighting, which is directly proportional to the illumination variability δy and relates to the histogram and the data of the to-be-processed pixel;
• a calculating unit for calculating a gain modulated value according the maximum gain, the minimum gain, the first weighting and the second weighting;
• and
• an image synthesizing unit for receiving the original Bayer image data and the gain modulated value, and multiplying the original Bayer image data by the corresponding gain modulated value to generate the modulated Bayer image data.