Question

To be implemented in MATLAB

Question 1: Consider the following images: a) office_1.jpg d) saturn.png b) pears.png e) rice.png c) peppers.png f) onion.png Extract green channel of all the above mentioned images. Apply the following operations on each image and write down your observations. Attach your output along with observation in a word file. 1. Addition 2. Subtraction 3. Multiplication 4. Division Choose three scalars for addition, subtraction, multiplication and division. One scalar must be 14 and second scalar must be 64 and the last scalar must be 8 Question 2: Use built-in function to find connected components in the image: coins.png Use built in function to extract all alphabets from the image: text.png and save them with .png extension. a. b. Bonus: Implement connected component algorithm yourself and find connected components in the image: coins.png

Answer 1

Q1)****since the images are not provided the procedure to find the same and the commands are provided below**** Green channel of a image(example-pears.png) can be extracted as follows(in MATLAB):-

rgbimage=imread('pears.png');

greenchannel= rgbimage( : ; : ; 2 );

Similarly the green channel of any image can be extracted. All you have to do is change the file name.

A scalar value is a matrix or an array with just a single value. So it can be considered as a 1×1 matrix. So addition of a scalar to a matrix can be done in the following way:-

scalarvalue1=14

scalarvalue2=64

scalarvalue3=8

addedvalue1= rgbimage+scalarvalue1;

addedvalue2=rgbimage+scalarvalue2;

addedvalue3=rgbimage+scalarvalue3;

For subtraction:-

subtractedvalue1=rgbimage-scalarvalue1;

And so on

For multiplication:-

multipliedvalue1=scalarvalue1.*rgbimage;

Dot(.) is used for element vise operation. Since it's a scalar multiplication dot can be omitted. Dot is useful in matrix multiplication.

For division:-

dividedvalue1=rgbimage/scalarvalue1;

Q2) The function bwconncomp can be used to find the connected components of an image. But this function can only work on binary image so we have to first convert it to gray image:-

gimage=rgb2gray('coins.png');

connectedcomponents=bwconncomp (gimage)

b) The words from a image can be done using the ocr function of MATLAB:-

text=ocr(gimage);

It can be saved as a png file using imwrite function as:-

imwrite(text , 'text.png');