Stanford

Week 3 Image Logic Exercises

fence-ivy.jpg image: Q1: Here is the fence-ivy.jpg Write code that picks out the pixels of the green leaves in the image (using the > avg * factor techniue! as in lecture". #or each green pixel iden$%ed! set its green value to &. 'he result is that the green leaves are changed to a sort of eird purple color! color! since se)ng green to &! e just have red and lue contriu$ng. Answer:

image + ne ,implemage(fence-ivy.jpg"/ ,implemage(fence-ivy.jpg"/

for (pixel: image" 0 11 2our 2our code here avg + (pixel.get3 (pixel.get3ed(" ed(" 4 pixel.get5reen(" 4 pixel.get6lue(""17/  if(pixel.get5reen(" > avg "0   pixel.set5reen(&"/ 8 8

print(image"/ Q2: Here is the stop.jpg image:

#or the stop.jpg image! rite code that picks out the lue sky (using the > avg * factor techniue! as in lecture". 9hange the lue pixels to e red+& green+& lue+& .. so it looks like nigh)me. ;djust your code so it changes the sky! ut not the hite le
image + ne ,implemage(stop ,implemage(stop.jpg"/ .jpg"/

for (pixel: image" 0 11 2our code here avg + (pixel.get3ed(" 4 pixel.get5reen(" 4 pixel.get6lue(""17/ if(pixel.get6lue(" > avg*=.= "0   pixel.set6lue(&"/   pixel.set3ed(&"/   pixel.set5reen(&"/ 8 8

print(image"/

Q3: Here is the cur.jpg image:

'he goal for this prolem is to change the cur to look lue. etect the red pixels of the cur using the avg techniue. #or each pixel! change its red and green values to e half the average value! and change its lue value to =. $mes the average value. n e?ect! this sets red and green lo and lue high! making it look kind of lue. @ote that the lue e?ect ill apply to the reddish plants o? to the right as ell A no they are lueish plants. Answer:

image + ne ,implemage(cur.jpg"/

for (pixel: image" 0 11 2our code here avg + (pixel.get3ed(" 4 pixel.get5reen(" 4 pixel.get6lue(""17/ if(pixel.get3ed(" > avg*=."0 pixel.set6lue(avg * =."/ pixel.set3ed(avg 1 "/

pixel.set5reen(avg 1 "/ 8 8

print(image"/ Image Bluescreen Exercises

B=: Here is the striped-%sh-green.jpg image: Write luescreen code to place this %sh in front of the yosemite.jpg ackground. 'he %sh has its of lue on it! ut thatCs ok since eCre using a green ackground in this case. ;djust the code so that all of the green toel elo the %sh disappears. Di
for (pixel: image" 0 avg + (pixel.get3ed(" 4 pixel.get5reen(" 4 pixel.get6lue(""17/ 11 your code here  if (pixel.get5reen(">avg"0   x+pixel.getG("/   y+pixel.get2("/   pixel+ack.getixel(x!y"/   pixel.set3ed(pixel.get3ed(""/   pixel.set5reen(pixel.get5reen(""/   pixel.set6lue(pixel.get6lue(""/

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8 print(image"/ B: Write luescreen code to modify the redood.jpg image! replacing the trunk and some of the ranches of the tree ith pixels from peles.jpg. 'he result is a sort of fanciful looking stone-tree image. ;djust the code so the loer trunk is changed to peles! ut not too much of  the greenery next to the trunk. image + ne ,implemage(redood.jpg"/ ack + ne ,implemage(peles.jpg"/ ack.set,ame,iFe(image"/

for (pixel: image" 0 avg + (pixel.get3ed(" 4 pixel.get5reen(" 4 pixel.get6lue(""17/ 11 your code here  if(pixel.get3ed(">avg*=.="0   x+pixel.getG("/   y+pixel.get2("/   pixel+ack.getixel(x!y"/   pixel.set3ed(pixel.get3ed(""/   pixel.set5reen(pixel.get5reen(""/   pixel.set6lue(pixel.get6lue(""/ 8

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print(image"/ B7: 'he I#ish reams of arisJ prolem.

'he striped %sh is facing right in front of a lue ackground. arts of the %sh are lue also A the eye and the ver$cal stripe in the middle. #or this prolem! eCll let the ackground image replace those to lue areas as ell.

Write luescreen code to place striped-%sh-lue.jpg in front of paris.jpg. n par$cular! adjust the code so that the lue ackground! the lue middle stripe! and lue eye of the %sh all sho the paris.jpg pixels. ;djust the code so the lue toel elo the %sh is almost completely replaced. image + ne ,implemage(striped-%sh-lue.jpg"/ ack + ne ,implemage(paris.jpg"/ ack.set,ame,iFe(image"/

for (pixel: image" 0 avg + (pixel.get3ed(" 4 pixel.get5reen(" 4 pixel.get6lue(""17/ 11 your code here  if(pixel.get6lue(">avg*&.K"0   x+pixel.getG("/   y+pixel.get2("/   pixel+ack.getixel(x!y"/   pixel.set3ed(pixel.get3ed(""/   pixel.set5reen(pixel.get5reen(""/   pixel.set6lue(pixel.get6lue(""/ 8

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print(image"/ Computer Harware Exercises W!at oes "oore#s law sa

%$'he numer of texts sent y a teenager doules every =L-M months. 'ransistors approximately doule in cost every =L-M months. 'he numer of pla
9N Hard rive - correct 3;O W!ic! one o& t!e &ollowing !arware components is t!e ac,'e -.rain/ oing t!e computa,on in t!e computer%

9N - correct Hard rive 3;O Heat ,ink W!ic! one o& t!e &ollowing !arware components pro'ies temporar$ .$te storage uring a computa,on0 .ut is erase w!en t!e power is turne o*%

9N Hard rive 3;O - correct Bits an B$tes Exercises

B=: Ho many di?erent values can e stored in = itP

 B: Ho many its are there in one yteP L B7: Qne yte can hold a value from & up to hat maximum valueP KK ilo.$tes "ega.$tes Exercises

B=: M&&& kiloytes (R6" is approximately eual to ho many megaytes (O6"P (#or all the prolems in this sec$on! just type in a numer. 'he unit (O6 or 56 or hatever" is alays speci%ed in the prolem text." M

B: ,uppose you have =& image %les! each taking up 7&& R6. ;out ho many O6 of space do they take up overallP 7

B7:,uppose you have four K&& O6 hard drives plus one  56 Eash drive. Ho many 56 of capacity is this overallP M

BM

,uppose e have a video camera that produces video data at the rate of  56 per hour.

：

3ecording for =K minutes creates aout ho many O6 of dataP (@ote that the anser is in O6" K=