Credits: Mini Project Description- Malin Premathilake
A Basic Image processing library implemented with ARM assembly
Description Image processing is a field where a digitized image is analyzed to obtain information or manipulated to improve the quality of the image. In image processing, the images are represented as a matrix. The RGB values of each pixel is represented by an element of the matrix. (i.e. A single pixel is represented using three values. Each of these values must be between 0-255) However, a grayscale image is represented using a single value per pixel. Hence for simplicity, You’ll be using only grayscale images Instead of actual images we’ll be using only the matrix representation :P There are many operations involved in image processing. Here, we are interested in the following three.
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Image inversion
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Rotation180
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Flip
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Inversion In this operation, the colors of an image is inverted. (Figure 2) This is done by applying the following formula to the matrix representation of the image Inverted_value = 255 - original_value E.g If the matrix representation of an image A of size 2x3 pixels is imA = [ 43 45 123 164 234 12] then the inverted image’s matrix representation will be imA_inv = 255 - [ 43 45 123 = [ 212 210 132 164 234 12] 91 21 243]
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Rotation180 In this operation, the image is rotated by 180 degrees (Figure 3) For this the matrix itself must be rotated. E.g If the matrix representation of an image A of size 3x4 pixels is imA = [ 43 45 123 132 164 234 12 211 32 121 1 200] then the rotated image’s matrix representation will be rot_imA = [ 200 1 121 32 211 12 234 164 132 123 45 43 ]
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Flip In this operation, the image is flipped along the vertical axis (Figure 4) For this the right side of the matrix must be switched with the left side. E.g If the matrix representation of an image A of size 3x4 pixels is imA = [ 43 45 123 132 164 234 12 211 32 121 1 200] then the flipped image’s matrix representation will be flp_imA = [ 132 123 45 43 211 12 234 164 200 1 121 32 ]
Program inputs and outputs
The program should take the inputs in the following order:
- Number of rows in the matrix
- Number of columns in the matrix
- Operation code (explained below)
- Elements of the matrix
The program should give the following output:
- Type of operation executed
- Resulting matrix
Operation codes are as below. Display the original without any change : 0 ( Original ) Invert the image : 1 ( Inversion ) Rotate the image by 180 degrees : 2 ( Rotation by 180 ) Flip the image : 3 ( Flip ) If any other value is given for the operation code, the following message should be printed and the program must exit.
Invalid operation e.g. Input matrix: imA = [ 43 45 123 132 164 234 12 211 32 121 1 200] Provide the inputs as below 3 4 1 43 45 123 132 164 234 12 211 32 121 1 200
The first 2 values denote the number of rows and columns, the 3rd value denotes the operation and the following values are the elements of the matrix Hence the output should be as follows:
Inversion 212 210 132 123 91 21 243 44 223 134 254 55