Spring 1999
Arch 411: CAD Fundamentals 1

Assignment #1: Digital Image Processing

Introduction

Since the advent of the personal computer, paint programs have become nearly as common as word processing programs. Not only are there many programs devoted to painting, but many programs for more complex tasks have paint programs built into them. Really sophisticated paint programs are usually called image processing or photo manipulation software to distinguish them from simpler, less powerful tools, but the guiding principles and underlying representations are much the same. Images produced by other programs (modelers, etc.) are often imported into paint programs. Scanners have helped in integrating real-life photographs into paint programs. There are even digital cameras, which bypass the need to scan photos by storing the image from the lens directly as a file instead of recording it on film. In this assignment you will use scanners and an image processing program (Photoshop) to digitally combine photos or slides to create a convincing, realistic presentation image.


Objectives

- To introduce the student with little or no computer experience to the computer, its hardware components, and its user interface.

-To start to develop good computing habits, including keeping files concise, reducing network traffic, saving work periodically, and making backups of work.

-To gain an understanding of how color is represented on a computer, and the effects this has on how editing works, output, file size, and other aspects of images.

- To gain an understanding of pixel-based painting, and be able to compare and contrast pixel-based systems to other systems based on other representations, learned later.


Requirements

Find two (or more) photographs, pictures, or slides to combine for this assignment. If you wish, you can substitute an existing, pixel-based image file (e.g., TIFF or GIF files) for one of the images to scan. Using methods demonstrated in class, you will combine these images into a single, convincing image and print it out. One approach which has been popular in the past has been to scan in a slide or photo of a model, and combine this with a slide or photo the project site, to produce an image of the design in its context. Another approach has been to combine an interior photograph with a landscape photo, to show a view from a room. These are just examples, however; feel free to combine any images into a convincing third image.

  

Student project by C.G.

Hand in grayscale laser prints of all three of your images: both of your originals, plus the final, combined image. If you incorporated any additional images into your project, hand in printouts of these as well. Making grayscale printouts of color projects often results in loss of contrast and aesthetic appeal, so you should also make an effort to show a screen version of your project to the instructors. You can also take this opportunity to point out each of the changes you made in the images, to make sure the instructors are aware of all the work you did.

Be prepared to discuss the project and the software in class. Be able to point out the sorts of things which were useful or made the project enjoyable, as well as the sorts of things which you found annoying, or which you felt hampered your ability to work quickly or make a convincing image. Be prepared to discuss how the techniques used in the project might be used in an office, as well as how they should not be used.

The assignment is due at the start of class on Tuesday, May 11. Projects handed in midway through class or immediately after class will be considered a day late. Do not skip class in order to try to finish your project.


Criteria

The most important criteria for this assignment is the realism of the combined image. The final image should be convincing. When I look at your image, it should be hard to tell which parts came from each source.

Pay attention to details when combining the images! Pay attention to perspective angles, shadows, sharpness, and contrast. Watch the "seams" where parts taken from one image meet parts from the other. In class, I will show how you can use the lasso, magic wand, and other tools to help make the final image look real. Use the tools appropriately, however. You should not wind up with a completely monotone sky, nor should you have the same tree, cloud, or pedestrian appearing dozens of times in the image.

Effort is likely to have an indirect effect on your grade. Placing a view of a landscape in a plain rectangular window, for instance, might be an easy way to satisfy the minimum requirements of the project, but such a project would not demonstrate an exceptional mastery of the tools available. It would not demonstrate that you knew how to warp an image to make perspective angles match, select irregularly shaped areas of images, or use a sandwiching technique to add objects to the middleground of an image. More credit will be given to projects which demonstrate a sophisticated understanding of the tools.

Making "improvements" to images will also help your grade. In creating a digital image which flatters a building, you should do the same sorts of things that a good photographer does. Remove litter from the scene; you can even take this principle further, and remove manufacturing or construction defects. Have people walking toward the building instead of away from it. Put inviting fires in the fireplaces.

You will not be graded on the quality of the building design, but you will be graded on the quality of the image. The final image should obey the rules of good composition: it should be balanced and interesting.

Projects will receive numerical grades according to the quality of the work. A project which fulfills all of the minimal requirements, but no more, will receive 7 out of 10 points. If the work is less than expected, for instance, if seams where images were combined are plainly visible, contrast levels are mismatched, and perspective and proportions are off, then the work will receive fewer than 7 points. If the work goes beyond the minimal requirements is well-composed and neat, and if it is difficult for me to tell where the images were joined, then the work will receive up to 10 points. Any projects turned in late will have one point deducted for each day (or portion thereof) which has passed since the due date. It is often better to turn in a mediocre project on time than to turn in an outstanding project several days late, when the course has moved on to other topics.


Concepts/Terminology

Storage media (floppy disks, zip disks, hard disks, formatting, backups)
Booting
Networks
Servers
Graphical User Interface
Icons
Menus
Windows
Dialog boxes
Tools
Clipboard/scrapbook
Pixel-based drawing
Layers
Scanner/screen/printer resolution
Grayscale vs. black and white
RGB color vs. indexed color
Dithering
Anti-aliasing


Other information for Spring 1999 Arch 411:


Last update: January 18,2009

Scott Johnson (sven@umich.edu)