Question

In c++

The iron-puzzle.ppm image is a puzzle; it contains an image of something famous, however the image has been distorted. The famous object is in the red values, however the red values have all been divided by 10, so they are too small by a factor of 10. The blue and green values are all just meaningless random values ("noise") added to obscure the real image. If you were to create a grayscale image out of just the red pixels, you may see the real image, although it is very very dark (way down towards 0 and you do not have to do this). Create a final corrected grayscale image by multiplying each red value by 10, scaling it back up to approximately its proper value and writing it to a .pgm file to create a grayscale image. What is the famous object?

Additional Criteria:

You must modify this program to incorporate functions and pointers.

Write a function called makeDataStructure that reads through the image file and creates a dynamically allocated array. This array contains only the red pixel values. Remember the red pixels are the 1st, 4th, 7th, 10th… numbers in the file. The function will create the array after it reads the first few lines of the .ppm file to determine the size of the image. Therefore, your code should work on an image of any size not just the given one. The function will return the pointer to this dynamically allocated array so it can be accessed from the main function. The function will also use the pass by reference option to give the size of the array to the main function.

Write another function called writeFile that takes the pointer to the dynamically allocated array created by makeDataStructure as a parameter as well as the size of the array then writes the header information and the corrected red values to an output .pgm file. The result will be a grayscale image of our photograph. It will look like a regular black and white photograph when viewed in Irfanview. The function prototypes are given below:

int* makeDataStructure(int &);

void writeFile(int *, int );

Answer 1

We can try solving this puzzle by using Matlab :

Image1 = imread("image.png");         % To read the given image

[rows, cols, dim] = size(Image1);      % To get the dimention of the image.

figure, imshow(Image1);                   %To display the loaded image

Red_plane = Image1(:,:,1);               % To get only red plane from the original image

figure, imshow(Red_plane);               %To display the Red plane gray scale image

for i=1:rows

    for j=1:cols

        Red_plane(i,j) = Red_plane(i,j) -10;             % Trying to recover the red pixel values according to question

    end;

end;

figure, imshow(Red_plane);         % To display the red plane after applying the changes.

Red_plane1 = Red_plane;

% If we want to make green and blue plane as zeros:

for i=1:rows

    for j=1:cols

        for k=2:dim

            Red_plane1(i,j) = 0;             % Making blue and green values of each pixel as zeros.

        end;

    end;

end;

figure, imshow(Red_plane1);          % Displaying red plane as color image with blue & green plane values are zeros.

% If the values in red plane is divided by 10 then the image pixel value should have a value in between 0-25 but when i checked the value of red plane it is in between 0-255 as usaul in normal image. So the operation must be specified properly which can be easily implemeted in for loop code. Even we can use different filters also based on the type of noise.