BSTJ 50: 3. March 1971: Television Coding Using Two-Dimensional Spatial Prediction. (Connor, D.J.; Pease, R.F.W.; Scholes, W.G.)

7 MB·English

Television Coding Using Two-
Dimensional Spatial Prediction

y D. J. CONNOR, RF. W. PEASE and W, G. SCHOLES
‘iain sed September 9,170)

Three clacton of aiferentil cuter» Rave Boen built which enplot
the ronimensional spatial correation present in Eeleision pictures
The thor cansee are dicinawshed aaconting 0 the Lcebniqne weed to
protit the velee af the pistons clament (pe) ty be ose £0 the Sst
lars, the prediction is thy onfuc of the previous climent along the
Sen tive averaged with ene oF mare elements iv the previous line
{of the same fete), Fe the ewomdl nas, the prediction te Ge exw of
the value of the previous pel withthe lat elemant ciference in the
previous Bne_ Tr the Third elas, the traneilter and reeciver ebooks
Ue preston jvom either the previnw element cr some cembination
of the previous element vith the elements in the prviows tive. The
Choice is baved ov diferances yonows! Driuten cements alend
Caer Phaow nee nowisble both a the toasamtter and rece, 40
ho ecicn information need be fransuited. Ip the aboenen of Iran
Inston errs, the pitures resin om ol three classes of coder
fre weave inno aver thone in whock only the prewons leant
Shged as a pred-tim, In pavtielar, vertical ond sloping edges are
thom well dened. Phe affect af a traneissien ert ox a vingle frame
ofthe reviged pieturs ct oarc “e fhe fst clean cf coder
Bu i mouch more viable fhe second anf tind claces

Anlonsty corelation in iclvision petures extends both horinntally
and vertieiy."* For a auember of wood neasace, mest sretenl pein.
five enecdere save exploited ly) Ive horagntslecmolatien:*

@) Im a novintersos system, acces 40 the vertinlly adjacent
Petre clement (al) regis some ate line of information
{about 8000 bits for Broudews TW or 2.000 bits for Picture
100 ea asz4 avetenCTrontout soma, wae ent

hone® Sorvien). Ine 2:1 interiasedapten, fl pls Tne
st by stored 10" bit for braseast or 250,000 for Pasture
hone Zersior|. 1 aevest tn hn verily anger pl fn the
ime fe ia desined, a tine of storage i required,

(4a) Mort telbvsion systems, including Ptturephone Service, ue an
inesaoed sean. Because of the storgo problem, sowee to the
‘rtcaly adjacent pl in tho smo Geld ie mos praca. Hom
‘ever, this pel Se about twice ae fer aay (epataly) fom the
terol pel ae ia the previous pel in the sama faa Kine. ‘The
‘erteal comeation of intensity within Fld ie thos ler than
the orignal eoreaton,

(28) Stasctical studios of telovision peturce suggested thot or
linow? praitve encoding very Kite oxtea redundaney gould
be removed by exotin the veri] eorrelion se well ws the
Torizontl eortlation.””

Give these rasan hy Ti a che af wertially adjacent pls
in various prieive ening chremee? Fie, in reoenk yeas the eat
‘of storage hae fallen deamatinl'y kd hone the exit remy re-
‘sired for moring one line ist scious objection, At present,
juod-bis line store using MOS shift resisters ooste about 890000
land fie on ove pitted eirenit hassel enmtaonig 0 cnelintine sash
‘ager Potuce eas shoul be ch lower {les a $100.0)

"To counter the second and third points above leew conser fr
rmorint the operation of w differenti wuantioer. A dierent quem
itor prow the value 0” the rumen pel by ming informal Dat
Tus alrendy beet tnnsited, ‘The diserepuncy etoreen the uncaded
lus ena tho prodiction ia quantized und waded to the predielion to
form the waded value ofthe eurunt po

‘Mos: practical differential quentiaew which make use of the
horizontal eorclatios of intensieynraduce piwzes of ererally weeest~
ble quality, except for sherp vertical ar dingorel edges. Theos are
blur and have an nnn "isynes" The problem in the pmaio=

Terentia] quantizer be no way! "ancioating” « verseal
the prediction i: makes i gross in sor at those

[Hy raling ua of information fom the oreo line ici posible to
ancsipate the veel edges ard mos: of the diagonal orcs. To std
‘this poeiility, we have built and/or simulated on a computer a aum-
ber of €iflerentie] quuatizors, Theee codes cnn be éivded into th

classes which ave distinguished ty the way in whieh the information
srumiAL DIREIRESTIAL coDES 1061

from the previa Hine is used to “antvipale” or predict the value nf
the exrrent pel. Tn Fig te give Ibs diagram of the pele eer thr
acre

The Bet elaes of cove, the prediction ie the evarege of the vane
af the previous ply As wil ls Yale of one ot mor ef “ne wetcely
‘ssjavne pele, gn DW cll tis “averaged prin” Th te
econ lass of sader, the pratition is the aum of anil the seed
Fos‘zonal slr differere or slap orseen elements oe previmis
line, eg, Cor | (D — Bh. Thie hve boon ealled “planar predie-

These frst exo ches uf wes use Hnearpredition eis the jv
liction few linen sin of peviogay eae intensities. Te third elas of
fader tt x nontinenepreietinn in thatthe eheier of prediction move
{2 signel-depenlent. "The precieion gan be etaer tor some Tina
ombincton of 4, 2, anor D The shoin is dapeadeat on the mage
Intade ef intensity ifle-rnrsn etosen she pre isthe previous eo]
tuciehborhood! of the curren pel, X. "Tht class of coder can be eae
"optional prodetion.” (R. F. Grakiem ae propose and sisted
senne coer of This tsp

Tn tne following sections wr deseube the patielae coders we have
luk and give some eewnples of processed pices We alga include
A iseneiot of she ellen. ts stamieior rte for Ue varios comme
rates.

"The soan format ie sinilar co thet use in Pietosephone Service:
‘there re B71 seins with a 2 inerlne, 248 clements pee Tne ad
1 fraaae vate 30 Te

“a stheincie uf general difercelal urtiaee thar uses nforsmtion
from the provatigg line fe give tn Tig. 2. Toe quitiver sharaccerie=
tice ate shown an Table [The partnular coder to deserted below
fier only 1 Fe Kaplememiee wf hie prerbetor. Note Ow with te
tiwenf sign predic thse are ence it ders.

"For eomparzon, me chase ae a rferenee aw element-oder (ie, Ue

Ti. ting af ita Sere felt mae Se ou
1062 eam sene sverme rzouieu. soURN, ARCH 167

sod fstab tego Te ew'4'B, © and reer tke nee Weare

value o? pl A is sei as e prediction) eving the sume cuensiser
characteritionas above, Although it might be argued that 3 would
make mare sens: 9 optimize the quantsing secle Zor ouch type of
Draditin, we found (at the subjedvely opium quantiing eesle
varied us zoueh with pietre contents with pilin abralegy. For
rnosteaynsicents, themstors, wo woe one quentizing aeale; 1 few
reaulls on varying the cussing seal ue, however, aso deserted ia
the next eestion

In che subjective wets, the 5 Snob by § inch raster wae viewed
‘hoongh a polersing seen from a distance of 30 inches in a roem
faving average office inination (20 foot candles}. Twn ses wore
bweds (elm model Reed, "Poneloe,” with a Grape Ielgronnd (Tg
Sa); and (i) a phningeaphie slice, "Raven," (Rig. 8).

In this opp of codes the prodiction i formed by adsing tke value of
pel d vo the vaire oi some combination of the pel 8, C ae. There
favre tere built end tested; the predictions used ‘wee: i) (A
Dy/2, LA + C72, (8) [A (C1 D)/2|/2. Pigure de abo w
‘ggram ofthe ercangement used to cst coder (2)

Th the absence of channel ero, the deslayed picture at the: ran

‘amu 1Eevcooen Ceanscrumerice

Tapot Taree

ee ee)
Soran mmremmaiee came 1053

ler iste ame ae at the eeeiver® sa hese only the trapemitte
ap wae it fr tas wal we tt

Th comparison wil she soferonve onde. all shes ef Les eadaes ge
snateanty tmpsoved ewiion the ers! ene moe a the loping
ledges. Horszontal_edgse acl shose sloping slightly mand appes

bueed ir eonpason Ach the sti es encesed by the ebavent
fivles, However is sac hrring whieh is ebjetively mse ess
Snir than she “edge buses” wes go ve seme ges ex
faved oe tae else eader. The geancKee noi in pitners encoded
Swi the everasad prolicion eodene a= aseeeiated uote with high
Yorucal spat) feequeneiee than swith high hoeental spatial tre-
Tuuences This wffeh t9 be expel brane the releisely Meee
Yoreal stop sve wil fell ie move Sroquent use of le iarger tnd
fr aeurate] quate differ signal in regions conteiing vertical
dew’, Ts pictuce aese wita ro dicelicnal peeps, che muse level
Je about te sure ns with fe element exer, Sarne absereor, however,
swentiones thts 3 apoio! lo les hgher fceueney nis.
Nn comune aasang she everegrd praietion” eadar2, (1 and
snywated prefers v6 (4) sine they wave eke to dey’ sly

end rlges with sunller psig rye than wa Ui). This 8 ade
Slanite sizes ¢1 reeeree af eH 3a thar poedieion yeu st
Sch edges ne an sipale, There wae very Bt eo chnnae “ace
Fhiers in} aad it sd ow Wo easran ext subyeetve teste in which

TERI onsale! gn! sight alld obsetvens were ase slate poe
Tienes bermesn peetes sli tel lag coder i: sa the zefeteno
finien With "Petco, al whit of the abil and seven ot te eight
tiakiled obeorrem prefewe se pitune givan by weer G1 Wath

Pi taa =|

a!

Wig, 8 Semen viewer eae see Presope and 2) Kae

aren," ll subjests prover the pietune given by coder 11. (Phe
‘killed shacrve all ematkel on the better ee rendition of the were
fa] svipes in Kacevs nse 4 bs ce squantizng sale Js mace comer,
fees aprewesteauign of wert) erges ste ptr from the
Feference coe bu: she gra ular nog st receaos, Ith eituahion,

rth der (1)

he couprison Zee Gun caer
preerale

"The wlmnent coder and ecors (7), (8) ond (were simulated on
a DDP.22E cempter eystoun Only’ ¢ single Tame wes provesed
ie eis ont pees tw jag fre Us fee noise. I the fst set of
fxperiunns the magiise of 12 0Teence oeteeen he anginal pie

tie (ood os eghs-int POM and picts from the above comers
stor dinplayed. Figures Sa and Sh shore the diecrspaney bebween the
PCM ened pituce wud petres coded with the element eoder sn

oder ii} seapectivey. (gures Se and dare Zor coders discuseed

Fig 4 Mage of tte once ise ae BL Cae
ah the retonte o, thy codes (UAE DAP ip prodstion (9 oder
GME B TESST ln Ca Spa pretenses
1058 Te ners srene eos JOUENAL, aaNet 101

below.) As explo che when rodee show diferncea along verti-
cal and diagore] edges. The average prediotion coer, on Une other
Tandy gave sliferenoes ciety along horizontal edges. Coder (5)
seer to show Uh least diaeepaney from the eight-bit eoded picture
‘Sor sbective rnroveuene aaa realined by ehoosing coder (8) over
coder i) in the experimensal mace

‘We al invertigated on the computer the ffcet of transmission
errs om single fame ofthe rseive piozue, It has been suggeied
tht bovause che average previeion ealers mle use of ffurtntion
fron ne provi Tne ae rll from previews ple on the entvent
Tine he fleck an eto" on sulmequen les wend be serians, Haw
ever Beoase the predievon wa average, the lel of ie etror decay
‘petty, For example, consider the fleet of an exor of 6 quantum
levels in coder i). This ere toute in the arty’ of inns errr
alk: in Table TE, Note Uae lh effet: of the erur decays rapidly
hth hosizanally and diagerat'y, but mere slowly vereaiy. Also,
he spasal derivative of the ereor pattern ie sma except sear the
covignal error This Tack show uly reduce the visibility of Uke ettor
pater, Ta aot, the pitcurs yeraced om he eemputer showed hat
tun sions ero (ex ehange of sizn on the outer level} conuted
Jw pettera tha: eos soared veble,

Contzas: the ssbilty of the errore ix Pigs. Ga and b. The picture
i Fig, a was code with the refers envir. The ppt dark live
‘Fae esuced by a partive-tomnegaive sign ehnge in an outer quantser
level. The lower light line rela Tow a nepativesta-postive so
shange in the thin? quandsce les. ‘The Mental igpe of err are
esean! in he peune in Fig. 6b whieh wae onda with coder (8). The
‘rrr in the outar quartzer ‘evel ie vieible asa small black dota the
tuts connor of tho left-hand eye. Tha error in the third quantizer
evel appenre ot «white elreals Coward the rekt end of che upper lip
Tn any event, the ezors are Far les visible than the equivalent errre
In Fig. ba

‘Two ooders were built and tested. The prodictone ured were (ie)
A+ (C~ Band 0) A+ (D— B72, Piguce 4b} shove a ahe-
mai for eo (x).

Both colors showed improvement ovar the reference ear, but not
cover the vores in the previous seston In parloula, the planus pre=
‘ction encoders gave rise to “edge-busynass” un edges sloping apr
1057
0H amaeuk sveret meemsreen. sores, ame un

worl crore Tigao fe) a4 (rath cai fet re rare Soa
SMe RT ee Le AER ME nee
eh de dtc Th Sethe en ee ok

“in en“ eet rok
5 ove, Easien A sig al tata yh

Baal Savy te

le ee Wl Tw alti, eer se gers ee at pubes
(les sling Hs ih,
{Coombe sn pe sussing to lee If af 2 in ig Vaal nee

Asad ¥ whos (© ~ Ri = — Be =a Toe values of A
es and A= UF) 24/2 sll otk be poe pewone of
(che exsa £2 tea lament coder but woree thap (4 “+ Di/2. Als,
an edge putes between A ara x and hesween D cad C, taco A+
ei) oll he n goon edietion of ©

‘Tae siesepanuy becvsen t2a pietne eocet af eigat-it PCM and
ther seed witt piles f21 show Fy Fis. Se Altri on the
erage, Uhe siiuuze shove “ve Wterpantios us he eqvialene