There is provided an image pipeline and a method therein for intra-coding an image frame. The image pipeline comprises a processing part followed by an encoding part supporting a plurality of intra-prediction modes used for intra-coding image frames. The method comprises receiving an image frame and for at least one block of pixel values in the image frame: predicting pixel values of the at least one block of pixel values using an intra-prediction mode supported by the encoding part and updating the image frame by adjusting at least one pixel value within the at least one block of pixel values so as to reduce a residual between the at least one pixel value and a corresponding predicted pixel value. Further, the method comprises intra-coding the updated image frame using at least one out of the plurality of intra-prediction modes.