Imaging systems with conformal image buffers

1. An image sensor, comprising:

an array of image pixels for capturing an image;

a conformal image buffer comprising:

a first storage for storing a pixel buffer lookup table; and

a second storage for storing only a portion of the captured image;

a write control engine for writing the portion of the captured image to the second storage using the pixel buffer lookup table, wherein the write control engine determines which portion of the captured image to store in the second storage based on a user-selected image transformation; and

a read control engine for reading out the portion of the captured image from the second storage using the pixel buffer lookup table.

2. The image sensor defined in claim 1 wherein the captured image comprises rows of image pixel values and columns of image pixel values, wherein each image pixel value is associated with an image pixel address, and wherein the portion of the captured image comprises selected image pixel values to be used in forming an output image from the captured input image.

3. The image sensor defined in claim 2 wherein the pixel buffer lookup table includes, for each row of image pixel values, a first column number that identifies a first pixel value in that row of image pixels to be used in forming the output image and a second column number identifying a last pixel value in that row of image pixel values to be used in forming the output image.

4. The image sensor defined in claim 3 wherein the pixel buffer lookup table further includes, for each row of image pixel values, an address offset corresponding to a memory address in the second storage at which the selected image pixel values from that row of image pixels is stored.

5. The image sensor defined in claim 2 wherein the output image includes output image pixel values each associated with an output image pixel address, the image sensor further comprising:

a transformation engine for determining image pixel addresses that correspond to each output image pixel addresses.

6. The image sensor defined in claim 5 , further comprising:

an interpolation engine for interpolating multiple image pixel values from the second storage to form a selected one of the output image pixel values.

7. The image sensor defined in claim 6 wherein the output image comprises a transformation of the captured input image, the image sensor further comprising:

an initialization engine for populating the pixel buffer lookup table.

8. The image sensor defined in claim 2 wherein the pixel buffer lookup table includes, for each pair of rows of image pixel values, a first column number that identifies a first column of image pixel values in that pair of rows of image pixels to be used in forming the output image and a second column number identifying a last column of image pixel values in that pair of rows of image pixel values to be used in forming the output image.

9. The image sensor defined in claim 8 wherein the pixel buffer lookup table further includes, for each pair of rows of image pixel values, an address offset corresponding to a memory address in the second storage at which the selected image pixel values from that pair of rows of image pixels is stored.

10. A method of transforming an input image having input image pixel values at input image pixel addresses to form an output image having output image pixel values at output image pixel addresses using an imaging system having a conformal image buffer, the method comprising:

with a write control engine, selecting a portion of the input image pixel values to store in the conformal image buffer based on a user-selected image transformation;

writing only the selected portion of the input image pixel values to the conformal image buffer at corresponding buffer addresses;

after writing the selected portion of the input image pixel values to the conformal image buffer, determining one or more buffer addresses associated with the user-selected image transformation of each output image pixel address;

for each output image pixel address, extracting input image pixel values from the determined one or more buffer addresses in the conformal image buffer; and

generating the output image pixel values from the extracted input image pixel values.

11. The method defined in claim 10 wherein the imaging system includes a transformation engine and wherein determining the one or more buffer addresses associated with a transformation of each output image pixel address comprises:

with the transformation engine, determining one or more input image pixel addresses corresponding to the transformation of each output image pixel address.

12. The method defined in claim 11 wherein the conformal image buffer further comprises a pixel buffer lookup table and wherein determining the one or more buffer addresses associated with the transformation of each output image pixel address further comprises:

determining the one or more buffer addresses associated with the transformation of each output image pixel address using the pixel buffer lookup table and the determined one or more input image pixel addresses corresponding to the transformation of each output image pixel address.

13. The method defined in claim 12 , further comprising:

populating the pixel buffer lookup table with transformation information specific to a type of image transformation.

14. The method defined in claim 13 , wherein the type of image transformation comprises a de-warping image transformation.

15. The method defined in claim 13 , wherein the type of image transformation comprises an image rotation.

16. The method defined in claim 13 , wherein the type of image transformation comprises an image rotation and a de-warping image transformation.

17. The method defined in claim 13 , further comprising:

populating the pixel buffer lookup table with transformation information specific to an additional type of image transformation that is different from the type of image transformation.

18. An imaging system-on-chip comprising:

a substrate;

an image sensor on the substrate having an array of image pixels for capturing images; and

storage and processing circuitry on the substrate, wherein the storage and processing circuitry comprises:

circuitry that selects a portion of each of the captured images to store based on a type of image transformation selected by a user;

a conformal image buffer comprising a pixel buffer that is configured to store only the selected portion of each of the captured images; and

a transformation engine that is configured to perform the selected type of image transformation in order to transform the captured images into transformed images to be displayed.

19. The imaging system-on-chip defined in claim 18 wherein the transformation engine is configured to determine a portion of each of the captured images that is to be used for transforming the captured images into the transformed images, and wherein the storage and processing circuitry is configured to transform the captured images into the transformed images to be displayed by storing the determined portion of each of the captured images in the conformal image buffer.

20. The imaging system-on-chip defined in claim 19 , wherein the conformal image buffer further comprises:

memory for storing a pixel buffer lookup table, wherein the storage and processing circuitry is configured to use the pixel buffer lookup table to determine the portion of each of the captured images that is to be used for transforming the captured images into the transformed images and to use the pixel buffer lookup table to determine particular memory addresses in the conformal pixel buffer that are used to store particular image pixel values associated with the determined portion of each of the captured images.