Efficient delivery of animated image files

1. A method of delivering animated images by an edge server to a web browser, comprising:

receiving through an interface a request for an image file;

detecting by a processor the image file as an animated image file;

generating two or more versions of the animated image file, including a first version of the animated image file having at least some frames at lower-resolution than corresponding frames in the animated image file, and including a second version of the animated image file having at least some frames at higher-resolution than corresponding frames in the first version of the animated image file;

sending the first version of the animated image file in response to the request for the image file, wherein the first version of the animated image file is received by a Document Object Model (DOM) virtualization client, wherein the DOM virtualization agent is injected by adding JavaScript client code in a head section of a webpage file associated with the image file, wherein the DOM virtualization client updates a DOM element associated with the image file using the first version of the animated image file instead of the image file, and

wherein the updating of the DOM element using the first version of the animated image file instead of the image file is kept transparent to the web browser; and

delaying delivery of the second version of the animated image file until a subsequent request for the second version of animated image file is received.

2. The method of claim 1 , wherein the subsequent request for the second version of the animated image file is sent by the DOM virtualization client, and wherein the sending of the subsequent request is kept transparent to the web browser.

3. The method of claim 1 , wherein the DOM virtualization client updates a DOM element associated with the image file using the second version of the animated image file, and wherein the updating of the DOM element using the second version of the animated image file instead of the image file is kept transparent to the web browser.

4. The method of claim 1 , further comprising detecting a file type of the image file.

5. The method of claim 1 , wherein the image file comprises a GIF animated image file.

6. The method of claim 1 , further comprising determining a number of versions of the image file that are sent to the DOM virtualization client and resolution of at least some frames of each version of the animated image file.

7. An edge server for delivery of images to a web browser, comprising:

an interface receiving a request for an image file;

a processor configured to:

detect the image file as an animated image file;

generate two or more versions of the animated image file, including a first version of the animated image file having at least some frames at lower-resolution than corresponding frames in the animated image file, and including a second version of the animated image file having at least some frames at higher-resolution than corresponding frames in the first version of the animated image file;

send the first version of the animated image file in response to the request for the image file, wherein the first version of the animated image file is received by a Document Object Model (DOM) virtualization client, wherein the DOM virtualization agent is injected by adding JavaScript client code in a head section of a webpage file associated with the image file, wherein the DOM virtualization client updates a DOM element associated with the image file using the first version of the animated image file instead of the image file, and

wherein the updating of the DOM element using the first version of the animated image file instead of the image file is kept transparent to the web browser; and

delay delivery of the second version of the animated image file until a subsequent request for the second version of animated image file is received; and

a memory coupled to the processor and configured to provide the processor with instructions.

8. The edge server of claim 7 , wherein the subsequent request for the second version of the animated image file is sent by the DOM virtualization client, and wherein the sending of the subsequent request is kept transparent to the web browser.

9. The edge server of claim 7 , wherein the DOM virtualization client updates a DOM element associated with the image file using the second version of the animated image file, and wherein the updating of the DOM element using second version of the animated image file instead of the image file is kept transparent to the web browser.

10. The edge server of claim 7 , further comprising detecting a file type of the image file.

11. The edge server of claim 7 , wherein the image file comprises a GIF animated image file.

12. The edge server of claim 7 , wherein the memory is further configured to provide the processor with instructions which when executed cause the processor to: determine a number of versions of the image file that are sent to the DOM virtualization client and resolution of at least some frames of each version of the animated image file.

13. A computer program product for delivering images by an edge server to a web browser, the computer program product being embodied in a tangible computer readable storage medium and comprising computer instructions for:

receiving through an interface a request for an image file;

detecting by a processor the image file as an animated image file;

generating two or more versions of the animated image file, including a first version of the animated image file having at least some frames at lower-resolution than corresponding frames in the animated image file, and including a second version of the animated image file having at least some frames at higher-resolution than corresponding frames in the first version of the animated image file;

sending the first version of the animated image file in response to the request for the image file, wherein the first version of the animated image file is received by a Document Object Model (DOM) virtualization client, wherein the DOM virtualization agent is injected by adding JavaScript client code in a head section of a webpage file associated with the image file, wherein the DOM virtualization client updates a DOM element associated with the image file using the first version of the animated image file instead of the image file, and

wherein the updating of the DOM element using the first version of the animated image file instead of the image file is kept transparent to the web browser; and

delaying delivery of the second version of the animated image file until a subsequent request for the second version of animated image file is received.

14. The computer program product of claim 13 , wherein the subsequent request for the second version of the animated image file is sent by the DOM virtualization client, and wherein the sending of the subsequent request is kept transparent to the web browser.

15. The computer program product of claim 13 , wherein the DOM virtualization client updates a DOM element associated with the image file using the second version of the animated image file, and wherein the updating of the DOM element using the second version of the animated image file instead of the image file is kept transparent to the web browser.