[+] Add a1 files

2021-09-17 15:19:56 -04:00
parent 08a1648a77
commit c1b09b7f4c
9 changed files with 526 additions and 2 deletions
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+"""CSC110 Fall 2021 Assignment 1, Part 5
+
+Instructions (READ THIS FIRST!)
+===============================
+
+Please follow the instructions in the assignment handout to complete this file.
+
+Throughout this module, we assume that images are at least 4 pixels wide and 4 pixels high.
+
+Copyright and Usage Information
+===============================
+
+This file is provided solely for the personal and private use of students
+taking CSC110 at the University of Toronto St. George campus. All forms of
+distribution of this code, whether as given or with any changes, are
+expressly prohibited. For more information on copyright for CSC110 materials,
+please consult our Course Syllabus.
+
+This file is Copyright (c) 2021 Mario Badr and Tom Fairgrieve.
+"""
+from statistics import median
+
+import a1_image
+
+
+def create_example_pixel_data() -> list:
+    """Return a new list of pixels that can be used in the doctest examples. The list describes
+    an image that is 4 pixels wide and 4 pixels high. Each element in the list is a three-element
+    tuple that corresponds to the red, green, and blue colour channels, respectively.
+
+    The pixels appear in the order of left-to-right, bottom-to-top (i.e., the same as
+    a1_image.load_image).
+    """
+    return [(128, 128, 128), (35, 50, 65), (210, 32, 68), (32, 208, 43),    # y = 0 (bottom)
+            (130, 20, 42), (43, 44, 45), (17, 243, 82), (61, 85, 92),       # y = 1
+            (201, 23, 23), (23, 23, 23), (42, 180, 19), (16, 58, 29),       # y = 2
+            (1, 52, 128), (26, 123, 128), (71, 234, 82), (23, 108, 34)]     # y = 3 (top)
+
+
+def get_pixel(pixel_data: list, image_width: int, x: int, y: int) -> tuple:
+    """Return a new RGB-tuple of the pixel at location (x, y) from the pixels in pixel_data that has
+    width image_width.
+
+    Assume that pixel_data was obtained from an image using a1_image.load_image.
+
+    >>> example_pixels = create_example_pixel_data()
+    >>> get_pixel(example_pixels, 4, 0, 0)
+    (128, 128, 128)
+    >>> get_pixel(example_pixels, 4, 1, 2)
+    (23, 23, 23)
+    """
+    index = x + y * image_width
+    r, g, b = pixel_data[index]
+
+    return r, g, b
+
+
+def get_pixel_window(pixel_data: list, width: int, x: int, y: int) -> list:
+    """Return a new list of RGB-tuples of the pixel at (x, y), along with its neighbours, from the
+    pixels in pixel_data that has width image_width.
+
+    A neighbouring pixel is a pixel that "touches" the pixel at (x, y), including diagonals.
+
+    Assume that the location (x, y) is not on any edge of the image described in pixel_data.
+
+    >>> example_pixels = create_example_pixel_data()
+    >>> get_pixel_window(example_pixels, 4, 1, 1)
+    [(201, 23, 23), (23, 23, 23), (42, 180, 19), (130, 20, 42), (43, 44, 45), (17, 243, 82), \
+(128, 128, 128), (35, 50, 65), (210, 32, 68)]
+    >>> get_pixel_window(example_pixels, 4, 2, 2)
+    [(26, 123, 128), (71, 234, 82), (23, 108, 34), (23, 23, 23), (42, 180, 19), (16, 58, 29), \
+(43, 44, 45), (17, 243, 82), (61, 85, 92)]
+    """
+    return [get_pixel(pixel_data, width, x + j, y + i) for i in range(1, -1 - 1, -1)
+            for j in range(-1, 1 + 1)]
+
+
+def separate_colour_channels(rgb_pixels: list) -> dict:
+    """Return a dictionary mapping the strings 'r', 'g', and 'b' to a list of the red, green, and
+    blue colour channels, respectively, in rgb_pixels. The value lists should have the same order
+    as rgb_pixels.
+
+    >>> example_pixels = create_example_pixel_data()
+    >>> separate_colour_channels(example_pixels) == \
+    {'r': [128, 35, 210, 32, 130, 43, 17, 61, 201, 23, 42, 16, 1, 26, 71, 23],\
+    'g': [128, 50, 32, 208, 20, 44, 243, 85, 23, 23, 180, 58, 52, 123, 234, 108],\
+    'b': [128, 65, 68, 43, 42, 45, 82, 92, 23, 23, 19, 29, 128, 128, 82, 34]}
+    True
+    """
+
+
+def calculate_median_colour(colour_channels: dict) -> tuple:
+    """Return the median colour in colour_channels.
+
+    The median colour is the median value of each colour channel, type converted to an integer.
+
+    Hint: use median from the statistics module. Be careful because the call to median may return a
+    float.
+
+    >>> example_pixels = create_example_pixel_data()
+    >>> separated_colour_channels = separate_colour_channels(example_pixels)
+    >>> calculate_median_colour(separated_colour_channels)
+    (38, 71, 55)
+    """
+
+
+def apply_median_filter(pixel_data: list, image_width: int, image_height: int) -> list:
+    """Return a new list of pixels formed from the corresponding pixels in pixel_data (that
+    represents an image with width image_width and height image_height), except with a median filter
+    applied to the pixels.
+
+    The median filter should not process boundaries (i.e., the edges of the image), so the returned
+    new list of pixels represents an image with width image_width - 2 and height image_height - 2.
+
+    >>> example_pixels = create_example_pixel_data()
+    >>> apply_median_filter(example_pixels, 4, 4)
+    [(43, 44, 45), (35, 58, 45), (42, 52, 45), (26, 108, 45)]
+    """
+    windows = [get_pixel_window(pixel_data, image_width, x, y)
+               for y in range(1, image_height - 1) for x in range(1, image_width - 1)]
+    window_channels = [separate_colour_channels(window) for window in windows]
+    return [calculate_median_colour(window_channel) for window_channel in window_channels]
+
+
+def run_median_filter_example(source: str, destination: str) -> None:
+    """Apply the median filter to an example image file at source and save the result in
+    destination.
+    """
+    original_pixel_data, original_width, original_height = a1_image.load_image(source)
+
+    new_pixel_data = apply_median_filter(original_pixel_data, original_width, original_height)
+
+    new_width = original_width - 2
+    new_height = original_height - 2
+    a1_image.save_image(destination, new_pixel_data, new_width, new_height)
+
+
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()
+
+    # When you are ready to check your work with python_ta, uncomment the following lines.
+    # (Delete the "#" and space before each line.)
+    import python_ta
+    python_ta.check_all(config={
+        'extra-imports': ['statistics', 'a1_image'],
+        'max-line-length': 100
+    })