The present invention discloses a method for coding an image, a method for decoding an image, a method for processing image data, and devices thereof. The method for coding the image includes: determining a current intra coding block that uses a constrained intra prediction method among current inter coded frames; determining that neighboring coding blocks that are adjacent to the current intra coding block include a neighboring inter coding block; updating image data in the neighboring inter coding block based on an invariable value or image data in a neighboring intra coding block included in the neighboring coding blocks; and coding the current intra coding block based on the updated image data in the neighboring inter coding block. By using the methods and devices, the error recovery capability of an intra coding block may be improved, and the image data decoding quality may be improved.