Lab Color Space home

The No Brainer Curve
The basic color correction technique for the LAB color space

  1. Open an image file.  Convert the image to the LAB color space using the Image - Mode menu.
  2. Open a curves adjustment layer.
  3. In the Lightness channel, pick a point on the lower left (dark) portion of the curve (say at the quarter point) and move it down.
  4. Still in the Lightness channel, pick a point on the upper right (light) portion of the curve (say at the quarter point) and move it up.
  5. Steps 3 and 4 will increase the contrast of the image without changing the color in any way.
  6. In the channels drop down menu select the a (green - magenta) channel.
  7. Move the lower left (green) end point of the curve to the right.  Exact distance is not important but a suggested start is about 1/2 block to the right.
  8. Move the upper right (magenta) end point of the curve to the left.  You must move it so that the curve passes through the exact midpoint of the graph (where the horizontal and vertical mid-lines cross.)
  9. In the channels drop down menu select the b (blue - yellow) channel.
  10. Move the lower left (blue) end point of the curve to the right.  Exact distance is not important but a suggested start is about 1/2 block to the right.
  11. Move the upper right (yellow) end point of the curve to the left.  You must move it so that the curve passes through the exact midpoint of the graph (where the horizontal and vertical mid-lines cross.)

Saving a Curve as a Preset

  1. When you have a curve setting  that you would like to save click on the icon on the right side of the tab bar in the adjustments dialog box.
  2. Select "Save Curves Preset" from the menu.
  3. Give the curve a name ("No Brainer Curve"?)  and save.

  4. Later when you wish to apply this curve to an image bring up the curves dialog box (either directly or as an adjustment layer).
  5. Note:  Even though the curve was saved while in the LAB color space when you apply the curve your image could be in JPEG or CMYK.
  6. On the drop down menu "Curves" select the curve you wish to apply.  In this case the "No Brainer Curve" will be listed near the bottom of the list.
  7. The selected curve will be applied.

Before the no brainer curve correction
Painted Desert Badlands photo before No Brainer correction

After no brainer correction
Painted Desert Badlands photo after No Brainer correction