A method of compressing screen content for delivery to a client device, the method comprising: for each of a plurality of coding units corresponding to screen regions included in a screen at a particular time, classifying screen content, wherein screen content comprises data describing information displayed on a display, included in the coding unit as having a content type selected from among a plurality of content types, at least one of the content types comprising an image type; based on the classification of the screen content in each coding unit, assigning metadata including information about the classification of the screen content to each coding unit; generating a screen map including the metadata associated with each of the plurality of coding units, the screen map including data defining regions of the screen that require encoding and a type of encoding to be provided; for each of the plurality of coding units, based on a determination that the screen content has an image type, applying a progressive standards-based encoding to the screen content of that coding unit by means of one or more encoders, wherein the one or more encoders use the screen map for the encoding; transmitting compressed screen content bitstreams for each of the screen regions to the client device; determining whether a coding unit within the screen map can be improved based on the metadata associated with the coding unit and, if improvement is available, encoding of a higher-quality version of the screen content in the coding unit, which is subsequently transmitted to the client device as a bitstream; the determining comprising inspecting quality bits included in metadata defining a portion of the screen map associated with the coding unit to detect whether the quality of the encoded screen content is at the highest level or whether some improvement is available; and transmitting region information to the client device to allow for the client device to discern among types of encodings for routing to appropriate corresponding processing systems, and to determine specific areas of the display to be updated, for each of a plurality of coding units corresponding to screen regions included in a screen at a particular time, classifying screen content, wherein screen content comprises data describing information displayed on a display, included in the coding unit as having a content type selected from among a plurality of content types, at least one of the content types comprising an image type; based on the classification of the screen content in each coding unit, assigning metadata including information about the classification of the screen content to each coding unit; generating a screen map including the metadata associated with each of the plurality of coding units, the screen map including data defining regions of the screen that require encoding and a type of encoding to be provided; for each of the plurality of coding units, based on a determination that the screen content has an image type, applying a progressive standards-based encoding to the screen content of that coding unit by means of one or more encoders, wherein the one or more encoders use the screen map for the encoding; transmitting compressed screen content bitstreams for each of the screen regions to the client device; determining whether a coding unit within the screen map can be improved based on the metadata associated with the coding unit and, if improvement is available, encoding of a higher-quality version of the screen content in the coding unit, which is subsequently transmitted to the client device as a bitstream; the determining comprising inspecting quality bits included in metadata defining a portion of the screen map associated with the coding unit to detect whether the quality of the encoded screen content is at the highest level or whether some improvement is available; and transmitting region information to the client device to allow for the client device to discern among types of encodings for routing to appropriate corresponding processing systems, and to determine specific areas of the display to be updated,