Method and apparatus for removing general lens distortion from images

A system, comprising:

• at least one processor;
• and
• a memory comprising program instructions, wherein the program instructions are executable by the at least one processor to render an output image from an input image, wherein the input image has general geometric distortion, wherein the general geometric distortion includes at least one radial distortion component and at least one tangential distortion component, and wherein, to render an output image, the program instructions are executable by the at least one processor to:
• render each one-dimensional element in a first planar dimension of the input image to generate pixel values in a corresponding one-dimensional element in the first planar dimension of an intermediate buffer, wherein, to perform said rendering, the program instructions are executable by the at least one processor to, for each pixel in each element in the first planar dimension of the intermediate buffer:
• calculate a pixel coordinate in the first planar dimension, wherein the calculated pixel coordinate in the first planar dimension accounts for at least a portion of the general geometric distortion of the input image in the first planar dimension;
• and
• perform interpolation at the calculated pixel coordinate in the first planar dimension in the input image to generate a pixel value for the current pixel in the intermediate buffer;
• and
• render each one-dimensional element in a second planar dimension of the intermediate buffer to generate pixel values in a corresponding one-dimensional element in the second planar dimension of the output image, wherein, to perform said rendering, the program instructions are executable by the at least one processor to, for each pixel in each element in the second planar dimension of the output image:
• calculate a pixel coordinate in the second planar dimension, wherein the calculated pixel coordinate in the second planar dimension accounts for at least a portion of the general geometric distortion of the input image in the second planar dimension;
• and
• perform interpolation at the distorted pixel coordinate in the second planar dimension in the intermediate image to generate a pixel value for the current pixel in the output image;
• wherein at least a portion of the general geometric distortion present in the input image is not present in the output image.

A non-transitory computer-readable storage medium storing program instructions, wherein the program instructions are computer-executable to implement:

• rendering an output image from an input image, wherein the input image has general geometric distortion, wherein the general geometric distortion includes at least one radial distortion component and at least one tangential distortion component, and wherein, in said rendering an output image, the program instructions are computer-executable to implement:
• rendering each one-dimensional element in a first planar dimension of the input image to generate pixel values in a corresponding one-dimensional element in the first planar dimension of an intermediate buffer, wherein in said rendering the program instructions are computer-executable to implement, for each pixel in each element in the first planar dimension of the intermediate buffer:
• calculating a pixel coordinate in the first planar dimension, wherein the calculated pixel coordinate in the first planar dimension accounts for at least a portion of the general geometric distortion of the input image in the first planar dimension;
• and
• performing interpolation at the calculated pixel coordinate in the first planar dimension in the input image to generate a pixel value for the current pixel in the intermediate buffer;
• and
• rendering each one-dimensional element in a second planar dimension of the intermediate buffer to generate pixel values in a corresponding one-dimensional element in the second planar dimension of the output image, wherein in said rendering the program instructions are computer-executable to implement, for each pixel in each element in the second planar dimension of the output image:
• calculating a pixel coordinate in the second planar dimension, wherein the calculated pixel coordinate in the second planar dimension accounts for at least a portion of the general geometric distortion of the input image in the second planar dimension;
• and
• performing interpolation at the distorted pixel coordinate in the second planar dimension in the intermediate image to generate a pixel value for the current pixel in the output image;
• wherein at least a portion of the general geometric distortion present in the input image is not present in the output image.

A computer-implemented method, comprising:

• executing instructions on a specific apparatus so that binary digital electronic signals representing an output image are rendered from binary digital electronic signals representing an input image, wherein the input image has general geometric distortion, wherein the general geometric distortion includes at least one radial distortion component and at least one tangential distortion component, and wherein said rendering the output image from the input image comprises:
• rendering each one-dimensional element in a first planar dimension of the input image to generate pixel values in a corresponding one-dimensional element in the first planar dimension of binary digital electronic signals representing an intermediate buffer, wherein said rendering comprises, for each pixel in each element in the first planar dimension of the intermediate buffer:
• calculating a pixel coordinate in the first planar dimension, wherein the calculated pixel coordinate in the first planar dimension accounts for at least a portion of the general geometric distortion of the input image in the first planar dimension;
• and
• performing interpolation at the calculated pixel coordinate in the first planar dimension in the input image to generate a pixel value for the current pixel in the intermediate buffer;
• and
• rendering each one-dimensional element in a second planar dimension of the intermediate buffer to generate pixel values in a corresponding one-dimensional element in the second planar dimension of the output image, wherein said rendering comprises, for each pixel in each element in the second planar dimension of the output image:
• calculating a pixel coordinate in the second planar dimension, wherein the calculated pixel coordinate in the second planar dimension accounts for at least a portion of the general geometric distortion of the input image in the second planar dimension;
• and
• performing interpolation at the distorted pixel coordinate in the second planar dimension in the intermediate image to generate a pixel value for the current pixel in the output image;
• and
• storing the output image in a memory location of said specific apparatus for later use, wherein at least a portion of the general geometric distortion present in the input image is not present in the output image.