Religion 345:
Lab Session: Image Processing 1

Image Resizing

  1. Using Netscape, go to the Bayly collection and find a single image. Click on the image to display the larger jpeg version of that image. Use your mouse to point to the image, hold down the mouse button until the small window appears andselect Save As... . Save it to the desktop.

  2. Open Adobe Photoshop. Pull down the File menu, select Open, choose your image file from the desktop.

  3. After the image appears on the screen, pull down the Image menu, select Image size.

  4. Change resolution to 72 dpi; view the results.

  5. Make sure you're viewing the image 1:1: use Command+ (command-plus) to magnify the image, Command- (Command-minus) to make it smaller.

  6. Choose Image size from the Image pull-down menu again.

  7. In the Height box fill in 3 inches. (Default size of Mac and Windows Netscape and Mosaic screen is 500 pixels) (Note file size in info bar, lower left.)

  8. Pull down Filter menu, select Sharpen.

  9. Change this image from JPEG to GIF file format: Pull down Mode menu, select Indexed Color. Select 8 bits. (Note change in file size in info bar.)

  10. Pull down File menu, select Save As... Retain the old filename or give it a new filename - JUST MAKE SURE TO CHANGE THE .JPEG TO .GIF; make sure Desktop is at the top pull-down (destination) menu; and choose Compuserve Gif as Format. Save.

Cropping

  1. In Photoshop, open JPEG image again.

  2. Double-click on cropping tool (left column, 4th row).

  3. In cropping tool dialog box, click on fixed target size, and type in 72 pixels/inch in Resolution box.

  4. Use your mouse to describe a rectangle on the image, outlining the detail you wish to create. When you move the cursor inside the rectangle you see a scissors icon; click inside the rectangle when you are ready to crop.

  5. Back up one step by typing Command-Z. (Command-Z performs and Undo on your last command.) This time fill in height OR width parameters in the cropping box. Repeat step 4 above.

  6. Sharpen (from the Filter menu) if necessary.

  7. Change this image from JPEG to GIF file format: Pull down Mode menu, select Indexed Color. Select 8 bits. (Note change in file size in info bar.)

  8. Pull down File menu, select Save As... Retain the old filename or give it a new filename - JUST MAKE SURE TO CHANGE THE .JPEG TO .GIF; make sure Desktop is at the top pull-down (destination) menu; and choose Compuserve Gif as Format. Save.

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