Method for image processing and apparatus for implementing the same

#This application claims priority benefit under 35 U.S.C. § 119(d) from European Patent Application No. EP 20 305 879, filed Jul. 30, 2020, the disclosure of which is incorporated by reference herein in its entirety.

#The present disclosure relates to the field of image processing, in particular image encoding for video stream compression.

#Film grain is usual in old motion pictures dating from the times movies were shot with a film camera. The grain, which was a result of chemical effects of the analog film used in the film camera, is no longer present in videos captured with a digital camera. Nevertheless it is common for film makers to add computer-generated grain in materials captured with a digital camera in order to reproduce the esthetic of old movies through the presence of film grain. In view of its random nature, grain present in an image can be modeled as an additive noise, and processed as such.

#The present subject disclosure will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawings, in conjunction with the accompanying specification, in which:

#FIG. 1 is a block diagram illustrating an exemplary image encoder/decoder system on which the proposed methods may be implemented in accordance with one or more embodiments;

#FIG. 2 illustrates an AR model with a lag L=2 that can be used to represent a noise pixel of a noise frame;

#For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the discussion of the described embodiments of the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. Certain figures may be shown in an idealized fashion in order to aid understanding, such as when structures are shown having straight lines, sharp angles, and/or parallel planes or the like that under real-world conditions would likely be significantly less symmetric and orderly. The same reference numerals in different figures denote the same elements, while similar reference numerals may, but do not necessarily, denote similar elements.

#In addition, it should be apparent that the teaching herein can be embodied in a wide variety of forms and that any specific structure and/or function disclosed herein is merely representative. In particular, one skilled in the art will appreciate that an aspect disclosed herein can be implemented independently of any other aspects and that several aspects can be combined in various ways.

#The present disclosure is described below with reference to functions, engines, block diagrams and flowchart illustrations of the methods, systems, and computer program according to one or more exemplary embodiments. Each described function, engine, block of the block diagrams and flowchart illustrations can be implemented in hardware, software, firmware, middleware, microcode, or any suitable combination thereof. If implemented in software, the functions, engines, blocks of the block diagrams and/or flowchart illustrations can be implemented by computer program instructions or software code, which may be stored or transmitted over a computer-readable medium, or loaded onto a general purpose computer, special purpose computer or other programmable data processing apparatus to produce a machine, such that the computer program instructions or software code which execute on the computer or other programmable data processing apparatus, create the means for implementing the functions described herein.