how can we represent a pixel to a character in image ?

Write a MATLAB script that allows reading an image file.

1. Convert color image to gray scale and display dot matrix

Image has a value from 0 to 1 (can be divided into 10 levels depending on the color scale

want to display)

2. Reduce the resolution of the current image to 64x64 pixels.

3. For each gray scale, insert the corresponding numeric character

alphabet letters.

[Walter Roberson]

hint:

('0':'9') - '0'

char()

Answer 1

[DGM]

To convert to unit-scale:

im2double() normalizes the image with respect to black and white

mat2gray() normalizes the image with respect to its extrema

To quantize the image:

rgb2ind() for RGB inputs

gray2ind() for gray inputs

or ...

multithresh() used with imquantize()

imquantize() quantize using specified input and output level lists

You can specify the output values in the call to imquantize(), so if you planned ahead, you should then just be able to cast the output of imquantize() using char(). Mutithresh() could be replaced with a simple linear sequence, but this is convenient and likely sufficient.

% ... assuming everything has been prepared ...
nlevels = 10;
inlevels = multithresh(inpict,nlevels); % get input levels
outlevels = double('A') + (0:nlevels); % some set of characters (represented in double)
outpict = imquantize(inpict,inlevels,outlevels); % quantize
outpict = char(outpict) % cast output values back to char

If you ask me, the assignment is vague and leads the student to approach the task using a counterproductive order of operations. You would preferably quantize after resizing, not before. If you resize your quantized image using imresize() defaults, it won't retain the same number of levels. You would have to specify nearest-neighbor interpolation if you did.

I also don't think it's very common or helpful to represent what is essentially an indexed image in unit-scale instead of using integers. Finally, if the final character array is the goal, then the entire bit with converting to unit-scale is an entirely unnecessary complication. It's also not clear what "the corresponding numeric character alphabet letters" actually means.

[Kimizuka]

Thanks your advice sir

Answer 2

[Image Analyst]

Hints: imread, rgb2gray, imshow, imresize, fprintf, size. With a double for loop over rows and columns and those 6 functions, you can read in, convert to gray scale, display, resize, and print out the numerical values of the 64x64 array to the command window.

This looks like a homework problem. If you have any questions ask your instructor or read the link below to get started:

How do I get help on homework questions on MATLAB Answers? - MATLAB Answers - MATLAB Central

Obviously we can't give you the full solution because you're not allowed to turn in our code as your own. But we can give you hints and advice on your own code.

[Kimizuka]

thanks, sir