RESAMPLING:
Also called interpolation (page 173 in your text)
In computer graphics interpolation means Photoshop's interpretation of what something should look like, when it does not have sufficient data to carry out your request. Interpolation is an averaging process. When you resize an image up or down or increase the resolution up or down, Photoshop searches for data to help support the application's decsion on how the resized image will look.

One of the tasks that you will need to perform frequently is the scaling or cropping of images. The command for changing the image size is Image>Image Size. The dialogue box displays the width and height of your work area, and you can change its dimensions by entering new values (make sure the units are set to pixels). To the right, you'll see a chain icon that indicates which perameters are linked, depending on whether you have selected Constrain Proportions and/or Resample Image at the bottom of the dialogue box.

Constrain proportions ensures that if the width is changed, the height changes accordingly (and vice versa). Unless you plan on intentionally distorting the image, perhaps as a special effect, this option should always be checked. The Resample Image option ensures that Photoshop resamples the image if you make any changes in its resolution. See your text (page 155) for more information on resampling (interpolation).

The Image Size dialogue box also displays a value for resolution. Ideally this value should be set to the screen resolution of 72 dpi, but this is more or less a cosmetic task. To a browser or HTML authoring program, it makes no difference whether the resolution of an image is set to 72, 120, or 300 dpi. To the browser a pixel is a pixel - it will always display the real size of the image. I mention this because it is different from desktop publishing. Resolution for print is different.

If you are printing your digital photographs you will see the difference in quality between 72 dpi, and 150 dpi.

Most often you will want to downsample, but in demonstrating upsampling in my video lesson, you will be able to understand both concepts. You should understand the difference between downsampling and upsampling after you complete this lesson.

One of the upsampling softwares is called Genuine Fractals. For more information about this go to:

http://www.ononesoftware.com/detail.php?prodLine_id=2

PART 1:
Using the tutorial "Resizing an Image" from your text (Lesson 5 page 171) downsample one image. You may use the enormouschair.jpg image from the text cd, or you can use an image of your choice. The image should have at least 300 dpi from which you will downsample.

Write one paragraph about your findings in downsampling.

PART 2:
From the three tutorials you completed (One on One text) from Lesson 4 "Making Selections" write one paragraph about your findings when working with the various selection tools reviewed in this lesson.

Please send both paragraphs via email text (no attachments please).

In the subject field of the email put your last name and first initial with the number of the homework.

Example: McIntosh J-HW2
Please use this format for each assignment that you email me throughout the semester.