ECTE 401考试卷子_原创文档.pdf

Q1(a)WhyisitimportanttostudyHVSinordertodevelopstill-imageandvideorelated

applicationsincludingthehardwave-perspectiveofconsumerelectronics?

Solution:Sensitivetomoderatelychangingpatterns

Notsensitivetorapidlychangingpatterns

Accuratemeasurementrequiresstabilizingintrinsicrapideye-movement

(b)DescribetheimportantstepsincompressinganimageusingJPEG

第一个框改为DCT

(c)WhatarethemajorimprovementinJPEG2000?

JPEGdrawback:blockiness,poorqualityintextcompression

JPEG2000advantages:

Superiorlowbitperformance

Superiorqualityintextcompression

Noblockiness

Q2(a)Describe3-stepsearchalgorithmusedinMPEG2compressionwiththehelpofa

diagram

(b)Usingtheconstantluminanceassumption………

Q2.Imagineanimageofsize1280x760.Ifthisimageisdown-sampledto2:1inboth

directions,whatisthesizeoftheimage?Iftheimageiscompressed16:1,whatisthesize

oftheimageinkilobytes(assumeagray-scaleimageof8-bit)?

Q1WhataretheadvantagesofJPEG2000.IllustratetheJPEG2000

compressionusingablockdiagram

Superiorlowbitperformance

Superiorqualityintextcompression

Noblockiness

Q1.Whatgivesrisetocompander(useprobabilitydistribution).Describehowitworks

withthehelpofdiagrams.

Q3WhywastheYUVsystemcapableofcateringforbothblackwhiteandcolour

television.

HereYistheluminance.Itisthegrayscaleimage.TheinitialtransmissionswereinY

only.LaterwhenY,U,Vweretelecast,blackandwhitetvscoulddisplayblackandwhite

usingYonlyandcolourcoulduseallthecomponentstodisplaycolour.

Q4Explainwhatabasisfunctionis?WhatarethebasisfunctionsinFourierTransform?

Basisfunctionisthesmallestbuildingblockofafunction.InFourierTransform,basis

functionsaresinesandcosinetermsofunlimitedfrequency(allthefrequenciesfrom–inf

toinfinity)

Q5Cantheinformationlostinquantizat