Microsoft Touts IE 11's Speedier JPEG Processing

IE 11

Internet Explorer 11 on Windows 8.1 displays JPEG graphics faster than previous IE browsers, Microsoft claims.

Specifically, Microsoft's newest browser on Windows 8.1 taps a computer system's graphics processing unit (GPU) during the loading and drawing of JPEGs, according to an IE blog post on Thursday by Jatinder Mann, an Internet Explorer program manager. This improved technology in IE 11 results in JPEG images loading at up to 45 percent faster than they did in previous IE browsers, Microsoft claims.

The time saved by handling JPEGs in this way is measured in milliseconds (ms), but there are other benefits besides speed. For instance, there's a positive effect in offloading some of the image processing to the GPU because it can free up CPU and memory resources on a system. Mann claims that that using IE 11 on Windows 8.1 can reduce a system's memory consumption by up to 40 percent in processing JPEGs.

Apparently, this technology only applies to JPEGs. However, it's still a big deal as Mann claimed that 47 percent of Web image requests are for JPEGs.

IE 11 and Windows 8.1 are both currently available at the "preview" stage. IE 11 on Windows 7 also is at the preview stage. Apparently, these JPEG processing improvements just apply to IE 11 on Windows 8.1.

The processing improvements are based on JPEG technology. JPEGs consist of one luma (brightness) and two chroma (color information) components. The two chroma channels (blue and red) can be compressed because "the human eye is more sensitive to the brightness of an image and less sensitive to color or hue," Mann explained. Most JPEGs have luma-to-chroma ratios of 4:2:0 or 4:2:2, indicating compression in the two chroma channels.

Earlier IE browsers would decode JPEGs by copying RGB (red, green, blue) bitmaps to the GPU. IE 11 on Windows 8.1 speeds up this decoding process. It sends the chroma components to the CPU, but it performs the color conversion in parallel at the GPU during the draw time, according to Mann.

Mann provided some numbers to back his speed claims. He said that IE 10 on Windows 8 takes 81 ms to draw a JPEG image, compared with just 57 ms for IE 11 on Windows 8.1.

Microsoft is recommending that developers ensure that JPEG images for the Web are compressed in 4:2:0 or 4:2:2 ratios to take advantage of this faster processing capability.

About the Author

Kurt Mackie is senior news producer for 1105 Media's Converge360 group.


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