July 7, 2009 / Idea File Supplement

Seven Steps to Enhance and Prepare Color Images

Written by Idea File Staff

All color images will need the color mode set to CMYK, the resolution set to 225 dpi, and the file format saved as jpeg. The following steps show how to go through the “basic three” steps and also show how to adjust image tone, remove color casts, add contrast and increase sharpness.

1.Check Color Mode

  • Open an image
  • Select the Image menu and choose Mode
  • Select RGB from the Mode menu if other Mode is selected. (Color correcting should be done in RGB mode)
2. Adjust Resolution

  • Select the Image menu and choose Image Size
  • Resample Image should not be checked Note: This option is located at the bottom of the window.
  • Enter 225 pixels/inch into the Resolution entry Note: the Width and Height should change when this step is performed.
  • Click OK
3. Tonal Adjustment

  • Select the Image menu and choose Adjust
  • Select Levels from the Adjust menu
  • Enter 12 and 243 for the Output Levels
  • Manually slide the outside Input triangles (the left is black and the right is white) to the base of the mountains. Do not go into the mountains. This will adjust the black point and white point of the image. Note: No more than 40 for the left Input Levels window or less than 200 for the right Input Levels window should appear.
  • Manually slide center Input triangle (gray) to adjust midtone levels of image. Stay within the range of 1.00 to 1.60. These numbers can be viewed as the slider is adjusted in the middle Input Level window. Note: This adjustment is strictly visual. Staying within the range of 1.00 to 1.60 will not hamper the image.
  • Click OK
4. Remove Color Cast

  • Using the Point Sampler Eyedropper click on an area that should be neutral gray
  • Select the Windows menu and choose Show Info. Note: The #1 in the Info Palette will indicate the values of each channel. In this case, R (Red) is 132, G (Green) 152, and B (Blue) is 133. R and B are similar in value, so the one we will be adjusting will be G. All values should be relatively equal. If two of the values are less than 130 or more than 150, then move the eyedropper around the image in neutral gray areas until two of the values fall between 130 and 150.
  • Select the Image menu and choose Adjust
  • Select Curves from the Adjust menu
  • Select the Channel that is out of range (see Note above to determine which channel needs to be corrected
  • Enter value in the Input entry (this number is the value of the channel that is out of range from the Info Palette)
  • Enter an averaged value in the Output entry (this number is the average of similar values of the two channels that were in range from the Info Palette)
  • Click OK
5. Sharpen Image

  • Select the Filter menu and choose Sharpen
  • Select Unsharp Mask from the Sharpen menu
  • Enter 106 for Amount
  • Enter 1.6 for Radius
  • Enter 10 for Threshold
  • Click OK
6. Set Color Mode

  • Select the Image menu and choose Mode
  • Select CMYK from the Mode menu

7. Save image

  • Select the File menu and choose Save As
  • Name files: 3 digit page #-3 digit position #_subject.jpg example: 001-001_zebra.jpg
  • Select JPEG for format
  • Click Save
  • Set Quality to 8 under the Image Options area
  • Set Format Options to Baseline (“Standard”)
  • Click OK
Idea File Staff

Idea File Staff reports are posts compiled by the Walsworth Yearbooks Marketing Department, covering a wide range of yearbook topics.