LTR FRAME UPDATING IN VIDEO ENCODING

There is provided techniques for LTR frame updating in a video encoding process. A method is performed by an image processing device as part of the video encoding process. The method comprises encoding a first LTR frame. The method comprises encoding a plurality of frames referencing directly or indirectly to the first LTR frame. The method comprises sequentially updating the first LTR frame by evaluating a cost for encoding a block of image data in one of the plurality of frames and by updating an image area in the first LTR frame when the cost fulfils a cost criterion. The image area is updated based on the block of image data in at least one of the plurality of frames. The method comprises encoding the sequentially updated first LTR frame as a second LTR frame.