[Cmul_merc] CMul Problems for today's practical lecture

[Fernando Pereira]

  Dear CMul students,

  I am sending you two problems for today's practical lecture which 
appeared in the first and second CMul exams of 2018/2019.

  Please keep them at hand during our lecture.

  Remind that all past CMul exams are available at 
http://www.img.lx.it.pt/~fp/comunicacao_multimedia/Exames_CMul/exames_cmul.htm 


  Regards

Fernando

***********************************************************************************************************

I (0.5 + 0.5 + 0.5 + 0.5 + 0.5 val. = 2.5 val.)

a)How many signal components are needed to see a gray image in a black 
and white television ? Which ones ?

b)How many signal components are needed to see a gray image in a colour 
television ? Which ones ?

c)How many signal components are needed to see a colour image in a 
colour television ? Which ones ?

d)In total, are there more samples or pixels in a black and white image 
? Why ?

e)Are there more luminance samples or total chrominance samples in a 
4:2:2 colour image ? Why ?


I (0.5 + 0.5 + 0.5 + 0.5 + 0.5 + 0.5 val. = 3.0 val.)

a)What is the difference between the bandwidth and the sampling 
frequency of a video signal ?

b)Indicate two benefits for Humans to have binocular vision.

c)What property relates the R, G and B values of a grey pixel ? Why ?

d)What are the chrominance (U and V) values of a grey pixel ? Why ?

e)Why do video services typically transmit chrominances (UV) with 
luminance and not directly primary colors (RGB) ?

f)Why do video services typically use 4:2:0 chroma subsampling ?



-- 
Fernando Manuel Bernardo Pereira, Ph.D., Professor
IEEE, EURASIP, IET Fellow, JPEG Reqs Chair
Instituto Superior Técnico, Universidade de Lisboa - Instituto de Telecomunicações
Av. Rovisco Pais, 1049-001 Lisboa, PORTUGAL
Phone:  + 351 21 8418460           Fax:    + 351 21 8418472
E-mail: fp at lx.it.pt WWW: http://www.img.lx.it.pt/~fp/