Question

% BACKGROUND:Image processing is the generation of a new image from one or more existing images. % MATLAB makes it easy to work with images by providing some basic functions % that allow you to read and write images in standard image -file formats, such as JPEG % Locate the attached photo of a blue bird stored in JPEG format, bbird.jpg (must be on same folder as script). % Fill in the ? in the code with correct values to change the color of the % bird from blue to red. clear close all clc % Reads the image from the file into an array named bbird bbird = imread('bbird.jpg'); % Displays the image image(bbird) % Forces display to have corrected aspect ratio axis equal % Forces the display to omit empty white areas above, below, left, or right of the image. axis tight % Dimensions of array-note the 3 dimensions [rows, cols, rgb] = size(bbird); % To look at individual values within the array, we need three indices, for example: % bbird (236,361,1) % bbird (236,361,2) % bbird (236,361,3) % These three numbers give the values of the red component, the green component, % and the blue component of the color of the pixel at location 236, 361 % (row 236 from the top, column 361 from the left). % A pixel is one square piece of a mosaic of colors that make up a digital image, in this % case a 525-by-775 image, and every pixel consists of three numbers, representing % the intensities of red, green, and blue light that together create the % color of the pixel in the human eye. Each of these numbers falls in the range 0 % to 255, with higher values meaning higher intensity % Suppose we wanted a red bird. We can do a little image processing to % change the blue bird into a red bird. All it takes is a nested for-loop: % Copies all the pixels of bbird into rbird. rbird = bbird; % The nested for-loop allows us to inspect each pixel to see whether it is % blue enough to be part of the bluebirds blue feathers. tic % timing the image processing using for-loop for row = ? for col = ? % The if-statement determines how blue a pixel is. % If the blue channel is more than 20% larger than the mean of the three color channels: if ? > 1.2 * mean(?)) % it sets the red channels value in redbirds pixel to be equal to the blue channel of bluebirds pixel?; % It then sets the green and blue channels in redbirds pixel to zero, so that % there is no hint of green or blue?; end end end

Answer 1

% BACKGROUND:Image processing is the generation of a new image from one or
% more existing images
%MATLAB makes it easy to work with images by providing some basic functions
% that allow you to read and write images in standard image -file formats, such as JPEG
% Locate the attached photo of a blue bird stored in JPEG format, bbird.jpg (must be on same folder as script).
% Fill in the ? in the code with correct values to change the color of the % bird from blue to red.
clear
close all
clc
% Reads the image from the file into an array named bbird
bbird = imread('bbird.jpg');

% Displays the image
image(bbird) ;

% Forces display to have corrected aspect ratio
axis equal ;

% Forces the display to omit empty white areas above, below, left, or right of the image.
axis tight ;

% Dimensions of array-note the 3 dimensions
[rows, cols, rgb] = size(bbird);

% To look at individual values within the array, we need three indices, for example:
% bbird (236,361,1)
% bbird (236,361,2)
% bbird (236,361,3)
% These three numbers give the values of the red component, the green component,
% and the blue component of the color of the pixel at location 236, 361
% (row 236 from the top, column 361 from the left).
% A pixel is one square piece of a mosaic of colors that make up a digital image, in this
% case a 525-by-775 image, and every pixel consists of three numbers, representing
% the intensities of red, green, and blue light that together create the
% color of the pixel in the human eye. Each of these numbers falls in the range 0
% to 255, with higher values meaning higher intensity
% Suppose we wanted a red bird. We can do a little image processing to
% change the blue bird into a red bird. All it takes is a nested for-loop:
% Copies all the pixels of bbird into rbird.
rbird = bbird;

% The nested for-loop allows us to inspect each pixel to see whether it is
% blue enough to be part of the bluebirds blue feathers.
tic % timing the image processing using for-loop
for row = 1:rows
for col =1:cols
% The if-statement determines how blue a pixel is.
% If the blue channel is more than 20% larger than the mean of the three color channels:
if rbird(row,col,3) > 1.2 * mean(rbird(row,col,:))
% it sets the red channels value in redbirds pixel to be equal to the blue channel of bluebirds pixel?
rbird(row,col,1) = bbird(row,col,3);
% It then sets the green and blue channels in redbirds pixel to zero, so that
% there is no hint of green or blue?;
rbird(row,col,2) = 0;
rbird(row,col,3) = 0;
end
end
end