Modified bicubic interpolation

A non-transitory computer medium comprising stored instructions that when executed by at least a processor of a computing device causes an algorithm to be performed, the instructions comprising:

• an acquisition module configured to acquire a plurality of amplitude values describing a set of pixels in an image;
• and
• a scaling module configured to perform image scaling on the image, comprising:
• an overshoot module configured to (i) identify a first pixel and a second pixel, wherein the second pixel precedes the first pixel in the set of pixels and (ii) determine if interpolation between the second pixel and first pixel will result in an interpolated pixel having an interpolated amplitude value outside of a range of amplitude values between the second pixel and the first pixel;
• a slope selection module configured to determine an interpolation slope at the first pixel for a curve that defines amplitudes of a set of interpolated pixels, wherein the interpolation slope is selected from (i) a first slope determined between the second pixel and the first pixel and (ii) a second slope determined between the first pixel and a third pixel that is adjacent the first pixel;
• and
• a rendering module configured to render the set of interpolated pixels between the second pixel and the first pixel using the interpolation slope at the first pixel.

A method, comprising:

• identifying at least a first pixel, a second pixel, and a third pixel in an image, wherein the second pixel precedes the first pixel in the image, and wherein the third pixel is adjacent to and follows the first pixel in the image;
• determining a first slope between the second pixel and the first pixel;
• determining a second slope between the first pixel and the third pixel;
• determining an interpolation slope based, at least in part, on the first slope and the second slope, wherein the interpolation slope is set to a substantially zero value when the first slope and the second slope have different signs;
• defining an interpolation curve having the determined interpolation slope at the first pixel;
• and
• scaling the image by generating a set of interpolated pixels between the second pixel and the third pixel along the interpolation curve.