Digital Photo 2: Vocabulary List 2

Define the following terms. Summarize the definitions in your own words.

  1. Curves: tonal correction control to alter contrast and brightness; lets you make nearly unlimited adjustments to tonal areas. Page 48 & 72 in Intro to Digital Imaging book.
  2. Histogram: a bar graph that shows the number of pixels at each brightness level in an image (number of dark pixels all the way to number of light pixels in an image). Used in levels command. Page 48 in Intro to Digital Imaging book.
  3. Unsharp Mask Filter: increases the apparent sharpness of an image; actual image detail is not increased.
  4. DPI vs. PPI: DPI is dots per inch and refers to the smallest mark made by a printer (1/300 inch square dot for 300 dpi); PPI is pixels per inch and refers to the unit used to measure the resolution of a bitmapped image on a monitor.
  5. RAM: Random-access memory is memory used by a computer to run an application and process info; it stores your work temporarily; you must save the file to permanently keep the information.
  6. Scan: to digitize a piece of art using a scanner so that it can be displayed and edited on a computer
  7. Selection: an area of an image that is isolated so changes can be made to it without affecting the rest. The selection can be moved around independent of the image content.
  8. Tolerance: range of pixels within which a tool operates (ex: range of shades or colors magic wand tool selects; higher # means more shades or colors will be selected)
  9. Clipboard: an area of the computer’s memory that stores selected pixels temporarily; it is accessed by using the Cut, Copy, Paste commands.
  10. Layer Mask: a mask that is attached to a layer so you can hide part of what is on that layer; it doesn’t permanently erase anything so you can always bring it back (reveal it); it is good for blending images together; you can also use a layer mask on an adjustment layer, such as levels, so the adjustment change only occurs in select parts. You use the paintbrush with black as the foreground color to mask or hide areas and white to reveal areas; opacity can also be changed so the affect is only partial
  11. Quick Mask Mode: a mode in which a colored, translucent mask covers selected parts of an image; used to make or clean up selections by painting with black or white with the paintbrush tool