Methods to compensate manufacturing variations and design imperfections in a capsule camera

A camera, comprising:

• an optical element;
• an image sensor;
• and
• means for preserving a record of characterization data created based on a model for images to be taken with the camera, the characterization data being derived from multiple images projected onto the image sensor by the optical element.

A method for characterizing a camera, comprising:

• Placing the camera inside a light absorption environment, and taking a first plurality of exposures;
• Placing the camera within a field-dependent reflectance environment, and taking a second plurality of exposures;
• and
• Processing the first and second pluralities of exposures to extract parameters values of a model for images to be taken with the camera.

A method for efficiently operating a camera having a sensor array organized as a two-dimensional array of picture elements (pixels), comprising:

• Providing an image on the sensor array;
• Measuring the responses of the pixels along a first dimension of the two-dimensional array to detect a first edge of the image and a second edge of the image;
• Measuring the responses of the pixels along a second dimension of the two-dimensional array to detect a third edge of the image and a fourth edge of the image;
• recording the area bounded by the first, second, third and fourth edges of the image as an active area of the image sensor;
• and
• processing and storing or transmitting only the responses of the pixels in the active area of the image sensor to subsequent image exposures.

A method for correcting a distortion in an optical element of a camera, the camera being housed in a swallowable capsule, comprising:

• Taking an image of a known pattern with the camera through a transparent window in the swallowable capsule;
• Determining distortions at predetermined locations on the image relative to the known pattern;
• Taking an image of a subject with the camera;
• and
• Using the determined distortions at the predetermined locations, undoing the determined distortions from the image of the subject.