CS 151: Project #5

Project 5: Blended Collages

Main course page

The purpose of this project is to make a program that processes a list defining a collage and builds the resulting image. The collage list information can specify if the program should apply an effect and/or an alpha blend to each image.


For this assignment you're going to add a couple of functions to the collage.py file you started in lab. One, buildCollage, will process the collage list information and build the output image. The other, putPixmapNoBlue, will be identical to putPixmap, except that it will not transfer blue screen pixels into the destination image.

  1. In your collage.py file, create a function buildCollage, as given below.
    def buildCollage( clist ):
        # assign to (cols, rows) the result of calling getImageSize with clist
        # assign to dst the result of calling graphics.Pixmap with cols and rows
        # for each item in clist
            # assign to filename the first element in item 
            # assign to x0 the second element in item
            # assign to y0 the third element in item
            # assign to operator the fourth element in item
            # assign to alpha the fifth element in item
            # assign to src the last element in item (index -1)
            # use a set of if/elif statements to apply the correct
            # operator to the image (this is several lines of code)
            # call putPixmap to put src into dst at location x0, y0 with blend alpha
        # return dst

    You can use testbuildcollage.py to test your buildCollage function. The test function assumes that your build collage knows what to do with the operator strings 'rbswap' and 'original', as we went over in lab.

  2. In your collage.py file, create a function putPixmapNoBlue that has the same arguments and does the same thing as putPixmap, but does not copy the src pixel into the destination image if the src pixel is part of the blue screen.
  3. Edit your buildCollage program so that it uses the sixth element in the collage information list to determine whether to call putPixmap or putPixmapNoBlue as the last step in the main for loop.
  4. Make a new python file collmain1.py that contains a single main function.

    The main function should create a collage information list, call readImages, call buildCollage, then write the image to a file. You can use the testbuildcollage.py file as an example. Your collage should us at least 4 pictures, multiple effects, at least one alpha blend, and include one blue screen image where the blue screen area is not copied into the collage. This is required image 1.

  5. Make a new python file, tricollage.py, that takes in three filenames from the command line. It should build a collage with the three images in a triangular configuration and write it out to a file. You can choose random effects for the three images, or pick specific effects. The collage should use at least two effects and one alpha blend. This is required image 2.



Make a new wiki page for your assignment. Put the label cs151s10proj5 on the page. Each of you needs to make your own writeup.

In addition to making the wiki page writeup, put the python files you wrote on the Academics server in your handin directory.

Colby Wiki

In general, your writeup should follow the outline below.