Create a function happy_face() that returns a 3D Rubby array containing the bitmap image of the \(5\text{ pixel}\times 4\text{ pixel}\) smiling face shown below.
Example Usage:
>> plot(happy_face(),20)
Note: The eyes are "midnight blue", the lips are "crimson", and the nose is black". (See RGB Color Table)
Create a function remove_green!(image) that alters image so that none of the pixels have any green remaining in them but they each still have the same red and blue values.
Example:
>> b = load_ppm("nautical.ppm"); nil
=> nil
>> plot(b)
=> nil
>> remove_green!(b)
=> nil
>> plot(b)
=> nil
 |
becomes |  |
Create a function dim!(image) that alters image so that each pixel is an \(\frac{1}{3}\) as bright as in the original image. Each pixel should also keep the same proportion of red, green, blue (subject to rounding errors).
Possible algorithm: For each row in the image and each column in that row:
-
Set the red component of the pixel array at that row and column
in the image to one-third of its old value rounded down to
a whole number.
Set the green component of the pixel array at that row and column
in the image to one-third of its old value rounded down to
a whole number.
Set the blue component of the pixel array at that row and column
in the image to one-third of its old value rounded down to
a whole number.
Example:
>> b = load_ppm("nautical.ppm"); nil
=> nil
>> plot(b)
=> nil
>> dim!(b)
=> nil
>> plot(b)
=> nil
| |
becomes |  |
Challenge: Create a function big_face() that returns a 3d bitmap array for a 300x300 face as shown in the following figure:
Example:
>> plot(big_face()) => nil
