{
"nbformat": 4,
"nbformat_minor": 0,
"metadata": {
"colab": {
"provenance": []
},
"kernelspec": {
"name": "python3",
"display_name": "Python 3"
},
"language_info": {
"name": "python"
}
},
"cells": [
{
"cell_type": "markdown",
"source": [
"**Name:**\n",
"\n",
"**Date:**\n",
"\n",
"**Description of activity:**\n"
],
"metadata": {
"id": "sczaGya92i48"
}
},
{
"cell_type": "markdown",
"source": [
"# Mount Google Drive\n"
],
"metadata": {
"id": "mv3Oarmb2zRK"
}
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"id": "1i3bvglG2d8z"
},
"outputs": [],
"source": [
"from google.colab import drive\n",
"drive.mount('/drive')"
]
},
{
"cell_type": "markdown",
"source": [
"# Import Libraries"
],
"metadata": {
"id": "GXNipdi-3F1Z"
}
},
{
"cell_type": "code",
"source": [
"from PIL import Image\n",
"from matplotlib import pyplot as plt"
],
"metadata": {
"id": "8Nmg8IhE3KfV"
},
"execution_count": 3,
"outputs": []
},
{
"cell_type": "markdown",
"source": [
"# Exercises\n",
"\n",
"In this activity you will learn how to do more complicated image manipulations by learning how to copy one image into another image.\n",
"\n",
"**Copying an image into a larger image**\n",
"\n",
"The following unfinished function, copyInto, takes as its input a picture to be copied, a blank canvas (an empty picture) in which to copy it, and the upper left *x* and *y* coordinates of the location on the canvas where you want to copy the picture.\n",
"\n"
],
"metadata": {
"id": "MJ8VoPpTy-mD"
}
},
{
"cell_type": "code",
"source": [
"def copyInto(picture, canvas, upperLeftX, upperLeftY):\n",
" # Assign values to the variables widthToCopy and heightToCopy \n",
" # based on whether or not there is room on the canvas to fit the\n",
" # entire picture. If there isn't enough room, we should copy less\n",
" # than the full width and height of the picture.\n",
"\n",
" #canvas argument will not be modified... \n",
" newCanvas = canvas.copy()\n",
"\n",
" pictureWidth = picture.width\n",
" pictureHeight = picture.height\n",
" canvasWidth = newCanvas.width\n",
" canvasHeight = newCanvas.height\n",
"\n",
" #These two lines only work if the picture doesn't spill off the canvas...\n",
" widthToCopy = pictureWidth\n",
" heightToCopy = pictureHeight\n",
"\n",
" # Copy however much of the picture as will fit over to the canvas edge\n",
" targetX = upperLeftX\n",
" for sourceX in range(widthToCopy):\n",
" targetY = upperLeftY\n",
" for sourceY in range(heightToCopy):\n",
" # Copy the color of the pixel at the source location to the \n",
" # destination location.\n",
" sourceColor = picture.getpixel((sourceX, sourceY))\n",
" newCanvas.putpixel((targetX, targetY), sourceColor)\n",
" targetY = targetY + 1\n",
" targetX = targetX +1\n",
" return newCanvas\n"
],
"metadata": {
"id": "8WMLzD5bAQxP"
},
"execution_count": 1,
"outputs": []
},
{
"cell_type": "code",
"source": [
"# Test the copyInto function here.\n",
"# Create two images of different sizes.\n",
"# Copy the smaller image into the larger image near the top left corner.\n",
"# Show the resulting image.\n",
"\n"
],
"metadata": {
"id": "4cewcCckBk6N"
},
"execution_count": 5,
"outputs": []
},
{
"cell_type": "markdown",
"source": [
"**Function improvement**\n",
"\n",
"The function as written so far only works if there is enough room on the canvas to copy the entire picture starting at the location you specify, as in the first illustration below. This is not always a safe assumption. The picture might be bigger than the canvas in at least one dimension, as in the second illustration, or it might be small enough to fit in the canvas but not when the copying starts at the specified upper-left corner, as in the third illustration.   
\n",
"\n",
"(In the illustrations, the black area represents the canvas in which we wish to copy the picture; any part of the picture covered with grid lines cannot be copied into the canvas.)\n",
"\n",
"**Design Questions:** How can you determine how much room is available in the canvas if you start copying the picture at location (upperLeftX, upperLeftY)? In other words, how can you determine the width of the space available from the specified upper left corner to the edge of the canvas? How can you determine the height of the space available from the same location?\n",
"\n",
"Answers here:\n",
"\n",
"\n",
"\n",
"**Analysis Questions:** Must the canvas be a blank empty picture? Could you also use this function to copy a picture onto another (non-blank) picture?\n",
"\n",
"Answers here:\n",
"\n",
"\n",
"Modify the copyInto function so that it only copies as much of the original or source picture as there is room for. To do this, use the min function to find the smaller of the two values - the width of the picture, and the space available on the canvas. Modify the widthToCopy variable to refer to this value. \n",
"Do something similar for heightToCopy. \n",
"\n",
"You will need to replace lines 16 and 17 with something like the following, where you fill in the question marks with appropriate expressions:\n",
"\n",
"widthToCopy = min(pictureWidth, ???????????)
\n",
"heightToCopy = min(pictureHeight, ??????????)\n",
"
\n",
"\n",
"After you have adjusted the width and height (if needed), the code above will copy the picture (or however much will fit) to the canvas. Run the code and test it with each of the scenarios from the images above. Show your results.\n",
"Make sure to comment your function appropriately.\n",
"\n"
],
"metadata": {
"id": "S6Mg9BgzAdC6"
}
},
{
"cell_type": "code",
"source": [
"# Test your modified copyInto function here\n",
"# Make sure to try each of the three scenarios matching the images above\n"
],
"metadata": {
"id": "meNr-pLpDp0a"
},
"execution_count": null,
"outputs": []
},
{
"cell_type": "markdown",
"source": [
"**Adding a matte**\n",
"\n",
"Write a new matte function that takes two parameters, a picture and a matte width, and creates a new picture consisting of the original picture surrounded by a matte of the appropriate width. (A matte is the sheet of cardboard or thick paper that often forms a border around a picture inside a frame.) The function should return the new picture with the matte. You may write your function so that it always creates a black matte, as in the examples below, or, if you have time, you may wish to add an extra parameter that specifies the matte color.\n",
"\n",
"**Design Questions:** Do you have other functions you can use to make writing this function easier? If you have the original picture and know the width of the matte on all sides of the picture, how should you compute the dimensions of the new picture with the matte? Where should the original picture be placed in the new picture? How should you specify that?\n",
"\n",
"Answers here:\n",
"\n",
"   \n"
],
"metadata": {
"id": "j_BFc8bYMfrO"
}
},
{
"cell_type": "code",
"source": [
"# Define the matte function here\n",
"\n",
"\n"
],
"metadata": {
"id": "peXqXT_jCcX-"
},
"execution_count": null,
"outputs": []
},
{
"cell_type": "code",
"source": [
"# Test matte function here\n",
"\n",
"\n"
],
"metadata": {
"id": "EYN2IJBlFcU2"
},
"execution_count": null,
"outputs": []
},
{
"cell_type": "markdown",
"source": [
"**Double matte** (If you have time)\n",
"\n",
"Sometimes pictures are framed with a wide matte and a second, much thinner matte of a contrasting color immediately around the picture. If you have time, you may want to try creating a double-matte effect.\n",
"\n",
"\n",
"\n"
],
"metadata": {
"id": "a92yyIooCzeW"
}
},
{
"cell_type": "code",
"source": [
"# Define the double matte function here\n",
"# Use the matte function; do not copy and paste large chunks of code!\n",
"\n"
],
"metadata": {
"id": "FOgwUiHNzInJ"
},
"execution_count": null,
"outputs": []
},
{
"cell_type": "code",
"source": [
"# Test the double matte function here\n",
"\n"
],
"metadata": {
"id": "VH1YSh3Lh9mX"
},
"execution_count": null,
"outputs": []
},
{
"cell_type": "markdown",
"source": [
"# Saving and Submitting\n",
"\n",
"Once you have created results that you are pleased with, skim through your notebook and make sure everything looks the way you expect. Make sure that your Code cells have been run and that your results are showing. If it all looks good, save this notebook as a pdf. (Go to File -> Print -> Save as PDF)\n",
"\n",
"Submit your PDF file on Kit."
],
"metadata": {
"id": "m8jTI0_OBDRM"
}
}
]
}