Techniques for adjusting the effect of applying kernels to signals to achieve desired effect on signal
View Patent ↗A method and apparatus for adjusting the effect of applying a kernel to a signal is provided. The adjustment may be based on the magnitude of an effect that a kernel matrix is intended to have on the signal matrix. The adjustments can be based on factors including, but not limited to, a signal-to-noise ratio of the signal data, properties of a device (e.g., lens) used to capture the signal data, or a metric that is derived based on an analysis of the signal data. Processing image data in accordance with an embodiment of the present invention is aimed at regaining lost contrast that may be due to properties of optics that are used to capture the image data.
1. A method comprising:
receiving a signal matrix comprising a plurality of pixel values corresponding to a portion of a captured image;
accessing a pre-constructed kernel matrix from storage that, when applied to the signal matrix, produces an effect of a certain magnitude;
calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix; and
based at least partially upon the one or more metrics, adjusting the effect of applying the kernel matrix to the signal matrix from the certain magnitude to an intended magnitude.
2. The method of claim 1 , wherein adjusting the effect of applying the kernel matrix to the signal matrix from the certain magnitude to an intended magnitude includes:
modifying the kernel matrix, based at least partially upon the one or more metrics, to generate a modified kernel matrix for the signal matrix; and
applying the modified kernel matrix to the signal matrix to achieve an effect of the intended magnitude.
3. The method of claim 1 , wherein adjusting the effect of applying the kernel matrix to the signal matrix from the certain magnitude to an intended magnitude includes:
applying the kernel matrix to the signal matrix to derive an intermediate result having an effect of the certain magnitude; and
scaling, based at least partially upon the one or more metrics, the intermediate result to adjust the effect from the certain magnitude to the intended magnitude.
4. The method of claim 1 , wherein the effect of applying the kernel matrix to the signal matrix includes enhancing image contrast in the portion of the captured image corresponding to the signal matrix.
5. The method of claim 1 , wherein the effect of applying the kernel matrix to the signal matrix includes de-noising the portion of the captured image corresponding to the signal matrix.
6. The method of claim 1 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix comprises:
calculating a first metric based upon a noise parameter of the signal matrix, wherein the noise parameter indicates how much noise is present in the portion of the captured image corresponding to the signal matrix.
7. The method of claim 1 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix comprises:
calculating a first metric based upon properties of a lens that is used to capture the captured image.
8. The method of claim 1 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix comprises:
calculating a first metric based upon at least a subset of the pixel values in the signal matrix, including a current pixel value being processed and one or more neighboring pixel values.
9. The method of claim 1 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix comprises:
calculating a first metric based upon a spatial location parameter of the signal matrix, wherein the spatial location parameter indicates where, in the captured image, the portion of the captured image corresponding to the signal matrix is located.
10. The method of claim 1 , further comprising, prior to applying the kernel matrix to the signal matrix, modifying the kernel matrix based on a motion blur characteristic of the captured image.
11. An image processing apparatus comprising:
a lens;
an image capture device that is optically coupled to the lens, wherein the image capture device captures an image; and
an image processor configured to perform the following operations:
receiving, from the image capture device, a signal matrix comprising a plurality of pixel values corresponding to a portion of the captured image;
accessing a pre-constructed kernel matrix from storage that, when applied to the signal matrix, produces an effect of a certain magnitude;
calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix; and
based at least partially upon the one or more metrics, adjusting the effect of applying the kernel matrix to the signal matrix from the certain magnitude to an intended magnitude.
12. The image processing apparatus of claim 11 , wherein the image processor adjusts the effect of applying the kernel matrix to the signal matrix by:
modifying the kernel matrix, based at least partially upon the one or more metrics, to generate a modified kernel matrix for the signal matrix; and
applying the modified kernel matrix to the signal matrix to achieve an effect of the intended magnitude.
13. The image processing apparatus of claim 11 , wherein the image processor adjusts the effect of applying the kernel matrix to the signal matrix by:
applying the kernel matrix to the signal matrix to derive an intermediate result having an effect of the certain magnitude; and
scaling, based at least partially upon the one or more metrics, the intermediate result to adjust the effect from the certain magnitude to the intended magnitude.
14. The image processing apparatus of claim 11 , wherein the effect of applying the kernel matrix to the signal matrix includes enhancing image contrast in the portion of the captured image corresponding to the signal matrix.
15. The image processing apparatus of claim 11 , wherein the effect of applying the kernel matrix to the signal matrix includes de-noising the portion of the captured image corresponding to the signal matrix.
16. The image processing apparatus of claim 11 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix comprises:
calculating a first metric based upon a noise parameter of the signal matrix, wherein the noise parameter indicates how much noise is present in the portion of the captured image corresponding to the signal matrix.
17. The image processing apparatus of claim 16 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix further comprises:
calculating a second metric based upon properties of the lens.
18. The image processing apparatus of claim 17 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix further comprises:
calculating a third metric based upon at least a subset of the pixel values in the signal matrix, including a current pixel value being processed and one or more neighboring pixel values.
19. The image processing apparatus of claim 16 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix further comprises:
calculating a second metric based upon at least a subset of the pixel values in the signal matrix, including a current pixel value being processed and one or more neighboring pixel values.
20. The image processing apparatus of claim 19 , wherein the effect of applying the kernel matrix to the signal matrix is adjusted based at least partially upon the first metric and the second metric.
21. The image processing apparatus of claim 17 , wherein the effect of applying the kernel matrix to the signal matrix is adjusted based at least partially upon the first metric and the second metric.
22. The image processing apparatus of claim 18 , wherein the effect of applying the kernel matrix to the signal matrix is adjusted based at least partially upon the first metric, the second metric, and the third metric.
23. The image processing apparatus of claim 11 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix comprises:
calculating a first metric based upon properties of the lens.
24. The image processing apparatus of claim 11 , wherein calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix comprises:
calculating a first metric based upon at least a subset of the pixel values in the signal matrix, including a current pixel value being processed and one or more neighboring pixel values.
25. The image processing apparatus of claim 24 , wherein the first metric is calculated based at least partially upon differences in pixel values between various pixel values in the subset of pixel values.
26. The image processing apparatus of claim 24 , wherein the first metric is calculated based at least partially upon a standard deviation in pixel values in the subset of pixel values.
27. The image processing apparatus of claim 24 , wherein the first metric is calculated based at least partially upon a histogram of the pixel values in the subset of pixel values.
28. The image processing apparatus of claim 24 , wherein the first metric is calculated, at least partially, by applying an edge detection mask to the pixel values in the subset of pixel values.
29. The image processing apparatus of claim 24 , wherein the first metric is calculated based at least partially upon entropy of pixel values in the subset of pixel values.
30. The image processing apparatus of claim 11 , wherein the image processor, prior to applying the kernel matrix to the signal matrix, modifies the kernel matrix based on a motion blur characteristic of the captured image.
31. A method comprising:
receiving a signal matrix comprising a plurality of pixel values corresponding to a portion of a captured image;
accessing a kernel matrix that, when applied to the signal matrix, produces an effect of a certain magnitude, wherein the effect includes sharpening the portion of the captured image corresponding to the signal matrix;
calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix, wherein the one or more metrics includes a first metric that is calculated based upon a noise parameter of the signal matrix, wherein the first metric indicates how much noise is present in the captured image; and
based at least partially upon the one or more metrics, adjusting the effect of applying the kernel matrix to the signal matrix from the certain magnitude to an intended magnitude, wherein adjusting the effect comprises adjusting the effect based at least partially upon the first metric such that the more noise there is in the captured image, the less sharpening is performed on the portion of the captured image corresponding to the signal matrix.
32. A method comprising:
receiving a signal matrix comprising a plurality of pixel values corresponding to a portion of a captured image;
accessing a kernel matrix that, when applied to the signal matrix, produces an effect of a certain magnitude, wherein the effect includes sharpening the portion of the captured image corresponding to the signal matrix;
calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix, wherein the one or more metrics includes a first metric that is calculated based upon a distance R between the portion of the captured image corresponding to the signal matrix and a lens center of the capture image; and
based at least partially upon the one or more metrics, adjusting the effect of applying the kernel matrix to the signal matrix from the certain magnitude to an intended magnitude, wherein adjusting the effect comprises adjusting the effect based at least partially upon the first metric such that the greater the distance R between the portion of the captured image corresponding to the signal matrix and the lens center of the captured image, the less sharpening is performed on the portion of the captured image corresponding to the signal matrix.
33. An image processing apparatus, comprising:
a lens;
an image capture device that is optically coupled to the lens, wherein the image capture device captures an image; and
an image processor configured to perform the following operations:
receiving, from the image capture device, a signal matrix comprising a plurality of pixel values corresponding to a portion of the captured image;
accessing a kernel matrix that, when applied to the signal matrix, produces an effect of a certain magnitude, wherein the effect includes sharpening the portion of the captured image corresponding to the signal matrix;
calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix, wherein the one or more metrics includes a first metric that is calculated based upon a noise parameter of the signal matrix, wherein the first metric indicates how much noise is present in the captured image; and
based at least partially upon the one or more metrics, adjusting the effect of applying the kernel matrix to the signal matrix from the certain magnitude to an intended magnitude, wherein adjusting the effect comprises adjusting the effect based at least partially upon the first metric such that the more noise there is in the captured image, the less sharpening is performed on the portion of the captured image corresponding to the signal matrix.
34. An image processing apparatus, comprising:
a lens;
an image capture device that is optically coupled to the lens, wherein the image capture device captures an image; and
an image processor configured to perform the following operations:
receiving, from the image capture device, a signal matrix comprising a plurality of pixel values corresponding to a portion of the captured image;
accessing a kernel matrix that, when applied to the signal matrix, produces an effect of a certain magnitude, wherein the effect includes sharpening the portion of the captured image corresponding to the signal matrix;
calculating one or more metrics based at least partially upon one or more parameters pertaining to the signal matrix, wherein the one or more metrics includes a first metric that is calculated based upon a distance R between the portion of the captured image corresponding to the signal matrix and a lens center of the captured image; and
based at least partially upon the one or more metrics, adjusting the effect of applying the kernel matrix to the signal matrix from the certain magnitude to an intended magnitude, wherein adjusting the effect comprises adjusting the effect based at least partially upon the first metric such that the greater the distance R between the portion of the captured image corresponding to the signal matrix and the lens center of the captured image, the less sharpening is performed on the portion of the captured image corresponding to the signal matrix.