CS 101 - Introduction to Computing, Spring 2007

Lab 8

This lab assignment will have you write a function in jython that will created a new images that will vertically repeat a picture by an amount given as a parameter.

Reminder

In the ACCC Labs that have JES, it can be found by:

1. Clicking on Start
2. Then click on All Programs
3. Then click on Class Applications
4. Then click on Engineering
5. Finally click on Jython Environment for Students

Duplicating and Image

def duplicateHorz():
  #Allow the user to pick up an image file
  file = pickAFile()
  #now convert the image in JES format
  pic = makePicture(file)

  orig_width = getWidth (pic)
  orig_height = getHeight (pic)

  new_pict = makeEmptyPicture (orig_width*2, orig_height)

  for x in range (1, orig_width):
    for y in range (1, orig_height):

      opix = getPixel(pic, x,y)

      npix1 = getPixel (new_pict, x, y)
      npix2 = getPixel (new_pict, x+orig_width, y)

      c = getColor (opix)
      setColor(npix1, c)
      setColor(npix2, c)

  openPictureTool(new_pict)

For this week's lab, you are to write a funcction that will take an integer value as its parameter. The function is to vertically diplicate an image (which is selected by the user using pickAFile()). The bew image will have the original image appear the same number of times as the value of the parameter. If the parameter has the value of 1, the function will just make a copy of the original image. If the parameter has the value of 2, the function will create an image that has 2 copies of the original image, one on top of the other. If the parameter has the value of 3, the function will create an image that has 3 copies of the original image, the first on top of the second and the second on top of the third. The value of the parameter will need to be checked to make sure it is 1 or greater.

Lab Assignment 8

Create a file using JES that will:

1. Contain a comment indicating
   • your Name,
   • Net-ID,
   • Course Name,
   • Assignment Name and
   • a short description of the assignment

2. Contain a JES function that will:
   • take a numeric value as a parameter given as an integer number. This value will indicate the number of duplicate images the final canvas will contain.
   • verify that the number is 1 or greater.
   • allow the user to pick an image using pickAFile().
   • use makeEmptyPicture() to create a blank canvas that will hold the proper number of duplicate images.
   • make the proper number of copies in the canvas. These copies are to be stacked vertically (one on top of the next).
   • display to created image
   • allow the user to save the created image in a file whose name is specified by using pickAFile().

If the command area of JES would be:

>>> duplicateVertical (1)

The result would be:

If the command area of JES would be:

>>> duplicateVertical (2)

The result would be:

If the command area of JES would be:

>>> duplicateVertical (3)

The result would be:

This function may call other functions that are built-in to JES or that you have written.

Submittal of the Lab Assignment

• You are submit your program electronically by placing it in the digital drop box in blackboard.
• Programs that are correct and submitted by noon on the Wednesday the lab assignment is discussed will receive an extra 10% on the score of the lab.
• When saving your program, use a meaningful name like lab8.py.
• When submitting your lab assignment, place all of the needed files it in a zippped folder (even if you are only submitting one file) with the name of yournetid_labX and submit that zipped folder to the digital drop box. For instance, if your net id is abc32 then the folder name should be abc32_lab8.

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