Canon Patent: In Camera RAW Processing With Arbitrary LUTs

A somewhat different Canon patent application. RAW processing with arbitrary LUTs. LUTs (Look Up Table) allow to apply specific color rendition parameters, for instance. If I got this patent right, it will allow to apply LUTs to the in camera RAW processing pipeline.

Canon patent application 2023121533 (Japan, published 8/31/2023) discusses technology and methods to integrate LUTs to the in camera RAW processing. From the patent literature:

An object of the present invention is to obtain an image having a degree of applicability desired by a user while using a lookup table desired by the user.

Description of the Related Art

A lookup table (hereinafter referred to as LUT) is generally used as means for correcting the color and contrast of an image. In many imaging devices, an LUT built in the imaging device can be applied to an image, or an LUT created by an external application can be loaded into the imaging device and applied to the image.

In addition, LUTs for converting to cinematic images, LUTs for special effects, etc. are often provided on the Web regardless of whether they are paid or not. can be applied.

However, LUTs provided on the Web, etc. are LUTs for converting into images that the creator considers good, and not everyone finds the images good. Some people may want to weaken the effect and apply it. In that case, it is necessary to first shoot an image without applying the LUT, and then combine the image as shot in post-production with the image to which the LUT is applied. It takes a lot of effort.

In the conventional example described above, the correction table changes depending on the determined scene. Even if it differs from the user’s preference, the user cannot change it according to his/her preference. Therefore, it is conceivable that the user adjusts the degree of application of the LUT before applying it to the image. However, when recording image data that has not been subjected to image processing, such as RAW moving image recording, naturally the LUT is not applied. Therefore, in order to reproduce the same image as the image viewed at the time of photographing at the time of post-editing, it is necessary to perform the same processing on a PC or the like using the LUT used and information on the degree of application, which takes time and effort.

In order to solve this problem, for example, the imaging apparatus of the present invention has the following configuration. That is, an image pickup apparatus having image pickup means and capable of connecting to a predetermined storage medium, an acquisition means for acquiring a first lookup table for image conversion from the storage medium, and Setting means for setting the degree of application of the first lookup table; and generating means for generating a second lookup table from the first lookup table based on the degree of application set by the setting means. and converting the image data obtained by the imaging means using the second lookup table generated by the generating means.

More Canon patents are listed here.

[via asobinet]