Home Certification Computer Vision Basics Coursera Answers – Free Certificate

# Computer Vision Basics Coursera Answers – Free Certificate

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3 ## Week 1: Computer Vision Basic Course Certification Answers : Coursera

Question 1: Computer vision includes which of the following?

• Automatic extraction of features from images
• All are correct
• None are correct
• Understanding useful information
• Analysis of images

Question 2: The image acquisition devices of computer vision systems capture visual information as digital signals?

• True
• False

Question3: Correct Syntax to read image in MATLAB in current folder

Question4: Select the correct option to crop top-left 50×50 section from the image read below.

• cropped_section = var_image(0:50,0:50)
• cropped_section = var_image(1:50,1:50)
• cropped_section = var_image[0:50,0:50]
• cropped_section = var_image[1:50,1:50]

Question5: What is initial data type of the image you read through imread function of MATLAB?

• int8
• double
• uint8

I2 = im2double(I1)

• Scales the image intensity values from 0 to 1
• Converts the image from uint8 to double format
• The array dimensions remain same

Question7: Select the options which assigns height and width of an image correctly in MATLAB.

• [height,width] = size(var_image );
• image_dimension = size(var_image );
• height = image_dimension(1)
• width = image_dimension(2)
• [width,height] = size(var_image );
• image_dimension = size(var_image );
• width = image_dimension(1)
• height = image_dimension(2)

Question8: Accessing Image Sub-Regions

subimg1 = img(1:50,1:50);

subimg2 = img(  end -49 :end,  end -49 :end);

SSD = sum(sum((double(subimg1) – double(subimg2)).^2));

SSD = immse(subimg1, subimg2) * numel(subimg1);

disp(SSD);

## Week 2: Computer Vision Basic Course Certification Answers : Coursera

Question9: Which of the following are area sources?

• Bulb
• All of these
• Sun at infinity
• Diffuser boxes
• White walls

Question10: Does distance of the light source affect the color of a pixel?

• No
• Yes

Question10: We lose depth information in perspective projection.

• True
• False

Question 11: Match column A with correct options in column in B

Question 12: Color Imaging – RGB Channels

%Get the size (rows and columns) of the image

[r,c] = size(img);

rr=r/3;

%Wrire code to split the image into three equal parts and store them in B, G, R channels

B=imcrop(img,[1,1,c,rr-1]);

G=imcrop(img,[1,1*rr+1,c,rr-1]);

R=imcrop(img,[1,2*rr+1,c,rr]);

%concatenate R,G,B channels and assign the RGB image to ColorImg variable

ColorImg(:,:,1) = R;

ColorImg(:,:,2) = G;

ColorImg(:,:,3) = B;

imshow(ColorImg)

## Week 3: Computer Vision Basic Course Certification Answers : Coursera

Question 13

Question 14: Low-level vision consists of:

1) feature detection and matching

2) early segmentation

• 1
• 1 and 2
• 2
• None

Question 15 : Image Gradient Magnitude

%Uncomment the code below to visualize Gx and Gy

%imshowpair(Gx,Gy,’montage’)

%Uncomment the code below to visualize Gmag and Gdir

%imshowpair(Gmag,Gdir,’montage’)

## Week 4: Computer Vision Basic Course Certification Answers : Coursera

Question 16: Match the Algorithms in column A with correct techniques in column B

Question 17: Aligning RGB Channels (using SSD)

[height, width] = size(img);

oneThird = floor(height/3);

B = img(1:(oneThird), :);

G = img((oneThird+1):(2*oneThird), :);

R = img((2*oneThird+1):(3*oneThird), :);

c_x = (341/2-25);

c_y = (400/2-25);

ref_img_region = double(G(c_x:c_x + 50, c_y:c_y + 50));

red_offset = offset(double(R(c_x:c_x + 50, c_y:c_y + 50)), ref_img_region);

shifted_red = circshift(R, red_offset);

blue_offset = offset(double(B(c_x:c_x + 50, c_y:c_y + 50)), ref_img_region);

shifted_blue = circshift(B, blue_offset);

ColorImg_aligned = cat(3, shifted_red, G, shifted_blue);

%ColorImg_aligned = cat(3, G, shifted_red, shifted_blue);

%ColorImg_aligned = cat(3, G, shifted_blue, shifted_red);

%ColorImg_aligned = cat(3, G, shifted_blue, shifted_red);

imshow(ColorImg_aligned);

% Find the minimun offset by ssd

function [output] = offset(img1, img2)

MIN = inf;

for x = -10:10

for y = -10:10

temp = circshift(img1, [x, y]);

ssd = sum((img2 – temp).^2, ‘all’);

if ssd < MIN

MIN = ssd;

output = [x, y];

end

end

end

end

3. Aditya Joshi