Trends in color imaging on the Internet

Trends in color imaging on the Internet Giordano Beretta Hewlett-Packard Laboratories Robert Buckley Xerox Architecture Center www AIC Color 2001, Rochester, NY

User expectations 2 • Many users access the Internet in the ofﬁce on fast workstations connected over fast links to the Internet • Increasingly, private homes are equipped with fast connections over DSL, cable modem, satellite, … • At home users often have fast graphics controllers for playing realistic computer games • The latest video game machines are very powerful graphic workstations • Today’s peripherals have “photo quality” color These user experiences set very high expectations for color imaging on the Internet R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Polarization of devices 3 The nomadic workforce • The new generation grew up on video games & WWW • Expect concise answers immediately on multiple media • The new working world is mobile and wireless • a comprehensive fast ﬁber optics network provides a global backbone • the “last mile” is wireless • computers are wearable • An appropriate viewing device has not yet been invented • the content will be electronic • the viewing conditions will be unpredictable • likely, a plethora of viewing devices will be in use R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Problems raised by new trend 4 • How do we deal with unknown viewing conditions? • How can we transmit images at very low bit rates? • How can we retrieve images on the Internet? R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

LCD display technology 5 • Cost falling faster than cost of CRT • Mainstream also on desktop • Most implementations different from CRT • white point not on Planckian Locus • sigmoidal tone reproduction curve • greenish blue • More brands with graphic arts specs • Characterization only slightly more complex than CRT • can apply ICC-based CMS R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Appearance mode 6 • CRT is darker than surroundings • perceived as object in ﬁeld of view • viewing conditions must be controlled • color ﬁdelity is important • LCD is brighter than surroundings • similar to illuminator viewing condition • visual system adapts to white point, memory colors • Consistency principle (Evans) • reproduction of relation among colors more important than absolute colorimetry R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

JPEG 2000 7 • Adds many features that allow Internet users to interact with the compressed data in ways not supported by JPEG • Achieves acceptable image quality at very low bit rates • Wavelet based • Can mimic foveation of human visual system R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Image compressed with JPEG 8 0.125 bpp R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Image compressed with JPEG 2000 9 0.125 bpp R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

JPEG codestream is packetized 10 • First few packets are such that you can decompress and obtain an image with more quality in the ROI (face) than in the periphery (surround) • As more packets arrive, you obtain the data to produce better quality in the surround, so that the entire image is rendered at the same quality • User can truncate the process anywhere in between R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Image compressed with JPEG 2000 11 ROI coding (face) equivalent to 0.125 bpp R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Image compressed with JPEG 2000 12 ROI coding equivalent to 0.25 bpp R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Image compressed with JPEG 2000 13 ROI coding equivalent to 0.5 bpp R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Image compressed with JPEG 2000 14 ROI coding equivalent to 1 bpp R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Algorithms for ROI 17 • Human vision collects low resolution overview in the retina’s periphery • High resolution views in the fovea with each ﬁxation as the eye jumps from ROI to ROI under top-down control ROIs 3K bytes 3K bytes 100K bytes L. Stark and C. Privitera, U.C. Berkeley & eFovea R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Image retrieval 18 • Text-based image retrieval: images are annotated and a database management system is used to perform image retrieval on the annotation • drawback 1: labor required to manually annotate the images • drawback 2: imprecision in the annotation process • Content-based image retrieval systems (CBIRS) overcome these problems by indexing the images according to their visual content, such as color, texture, etc. A goal in CBIR research is to design representations that correlate well with the human visual system R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Rendered images 19 • Stock photo agency images are rendered to a normalized intent • Typical consumer images are the raw output of digital cameras or scanners • Many CBIR algorithms rely on color histograms • Need to specify when images are unrendered • RIMM/ROMM RGB • Need algorithms to perform automatic rendering operation R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Conclusions 20 • At Color ‘97 in Kyoto we predicted the availability of cheap processing and fast cheap Internet • compared compression in the color domain to compression in the spatial domain; ﬁle formats • Today we see a trend towards bright LCD displays and wireless devices • color consistency more important than ﬁdelity • packetized low bit rate codestreams with ROI • contents based image retrieval • At Color ‘05 we will see • image-capable handheld devices with wireless Internet • world-wide dop-down image search & retrieval from handheld • incredibly bright handheld displays based on OLED R.R. Buckley & G.B. Beretta AIC Color 2001 Trends in color imaging on the Internet

Trends in color imaging on the Internet

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