A method of obtaining an image tile from a server by a a client, the method comprising: a client submitting a request to a server for meta-data associated with a compressed image file, wherein the server controls access to the compressed image file, wherein the compressed image file comprises a plurality of different resolution image layers; the server retrieving the requested meta-data directly from the compressed image file, and transferring the retrieved meta-data from the server to the client; the client generating a further request using the retrieved meta-data associated with the compressed image file; the client determining, from the retrieved meta-data associated with the compressed image file, the identity of the image layer that an image tile is being requested from and the coordinates of the image tile in the image layer; the client submitting the further request to the server for extracting the image tile from the compressed image file; wherein the image tile is to be extracted from one of the plurality of different resolution image layers, and wherein the further request comprises the identity of the image layer that the image tile is being requested from and the coordinates of the image tile in the image layer; the server extracting the requested image tile directly from the image layer in the compressed image file using the identity of the image layer and the coordinates of the image tile in the request, wherein the step of extracting the requested image tile comprises decompressing the requested image tile to a particular image resolution and quality; and transferring the decompressed image tile from the server to the client at the decompressed image resolution and quality. a client submitting a request to a server for meta-data associated with a compressed image file, wherein the server controls access to the compressed image file, wherein the compressed image file comprises a plurality of different resolution image layers; wherein the server controls access to the compressed image file, wherein the compressed image file comprises a plurality of different resolution image layers; the server retrieving the requested meta-data directly from the compressed image file, and transferring the retrieved meta-data from the server to the client; the client generating a further request using the retrieved meta-data associated with the compressed image file; the client determining, from the retrieved meta-data associated with the compressed image file, the identity of the image layer that an image tile is being requested from and the coordinates of the image tile in the image layer; the client submitting the further request to the server for extracting the image tile from the compressed image file; wherein the image tile is to be extracted from one of the plurality of different resolution image layers, and wherein the further request comprises the identity of the image layer that the image tile is being requested from and the coordinates of the image tile in the image layer; wherein the image tile is to be extracted from one of the plurality of different resolution image layers, and wherein the further request comprises the identity of the image layer that the image tile is being requested from and the coordinates of the image tile in the image layer; the server extracting the requested image tile directly from the image layer in the compressed image file using the identity of the image layer and the coordinates of the image tile in the request, wherein the step of extracting the requested image tile comprises decompressing the requested image tile to a particular image resolution and quality; and transferring the decompressed image tile from the server to the client at the decompressed image resolution and quality. wherein the step of extracting the requested image tile comprises decompressing the requested image tile to a particular image resolution and quality; and transferring the decompressed image tile from the server to the client at the decompressed image resolution and quality.