Method and an encoder for inter-encoding an image frame

An encoder for inter-encoding an image frame in a sequence of image frames, comprising circuitry configured to carry out a method for inter-encoding an image frame in a sequence of image frames, comprising:

• obtaining a compression level for each pixel block of the image frame, wherein the compression level corresponds to a quantization level and is higher for pixel blocks in some regions of the image frame than for pixel blocks in other regions of the image frame,
• inter-encoding the image frame in a first encoding pass using the obtained compression level for each pixel block of the image frame, wherein each pixel block is either inter-coded or intra-coded,
• identifying pixel blocks in the image frame that were intra-coded in the first encoding pass and for which the obtained compression level exceeds a compression level threshold,
• lowering the compression level for each identified pixel block, and
• inter-encoding the image frame in a second encoding pass using the lowered compression level for each identified pixel block and using the obtained compression level for each remaining pixel block.

A computer-readable storage medium comprising computer program code which, when executed by a computer, causes the computer to carry out a method for inter-encoding an image frame in a sequence of image frames, comprising:

• obtaining a compression level for each pixel block of the image frame, wherein the compression level corresponds to a quantization level and is higher for pixel blocks in some regions of the image frame than for pixel blocks in other regions of the image frame,
• inter-encoding the image frame in a first encoding pass using the obtained compression level for each pixel block of the image frame, wherein each pixel block is either inter-coded or intra-coded,
• identifying pixel blocks in the image frame that were intra-coded in the first encoding pass and for which the obtained compression level exceeds a compression level threshold,
• lowering the compression level for each identified pixel block, and
• inter-encoding the image frame in a second encoding pass using the lowered compression level for each identified pixel block and using the obtained compression level for each remaining pixel block.