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Pixel Art - Nested Loops

Learning Objectives

We are going to learn:

1. How to use nested for statements.
2. How to use multi-dimensional lists.

Exercises

Download the Medialib ex7 files from the gallery and complete the program in ex7.py to draw a greyscale pixel art image from given pixel values in a 2d list (64 x 64).

1. Each object a[i][j] in the list corresponds to the colour of the pixel on a scale from 0 (black) to 255 (white).
2. In lines 26 - 32, use nested for statements to loop through the list and draw each pixel using the Medialib rect(x,y,w,h,r,g,b) function where:
• x and y should be calculated from i and j in the loop
• w and h are the same and are predefined (e.g. w = h = 6 in the image below)
• r = g = b = a[i][j]

Be careful about the relations between the coordinate system of the screen and the subscript of the list:

Bonus: You may find the original image is a negative image of a cat. Draw the positive image of the cat beside the original image: