Image-capturing apparatus and method for correcting nonlinear images

An image-capturing apparatus comprising:

• an optical device which converts input light to an image having nonlinear characteristics over light intensity;
• an image sensor which converts the image having the nonlinear characteristics into an electrical signal;
• a converter which coverts the electrical signal into a digital signal;
• a correction unit which corrects the digital signal to generate a corrected signal having linear characteristics over the light intensity;
• a signal-processing unit which processes the corrected signal to be displayed as an output image.

A nonlinear image-correcting method for an image-capturing apparatus including an optical device having nonlinear characteristics and an image sensor which photoelectrically converts an input image having the nonlinear characteristics, the method comprising:

• converting input light to the input image having the nonlinear characteristics over light intensity so as to extend a dynamic range of the image sensor;
• converting the input image having nonlinear characteristics into an electrical signal;
• correcting the electrical signal to generate a corrected signal having linear characteristics over the light intensity;
• converting the corrected signal into a digital signal;
• and
• processing the digital signal to be displayed as an output image.

A nonlinear image-correcting method for an image-capturing apparatus including an optical device having nonlinear characteristics and an image sensor which photoelectrically converts an input image having nonlinear characteristics, the method comprising:

• converting input light to the input image having the nonlinear characteristics over light intensity so as to extend a dynamic range of the image sensor;
• converting the input image having the nonlinear characteristics into an electrical signal;
• converting the electrical signal to a digital signal;
• correcting the digital signal to generate a corrected signal having linear characteristics over the light intensity;
• and
• processing the corrected signal to be displayed as an output image.