Setting Advanced Color Curves | Top Previous Next Learn more at BibbleLabs.com

The advanced Histogram/Curves tool lets you to adjust the RGB color values of the image using both a curve and histogram graphical interface elements. For more information about curves and histograms, see the Understanding Advanced Image Editing Tools topic.

To set the RGB color levels of the image using curves:

1. | From the Tools menu, click Advanced.

2. | In the drop-down menu, click Histogram - Curves.

3. | Click Apply Curves to apply the custom curves to the image.

4. | If you have applied a crop to your image, click the check box in the lower left corner of the tool window to show histogram values only for the cropped area of your image.

5. | Open the color values drop-down menu and select a color from the list. You can adjust the curves for one specific color or for all three colors.

6. | To adjust the curve for all three color channels, select RGB.

Note: If you adjust the curve of an individual color (such as Blue), the curve for the Blue level is represented by a dashed blue line. If you adjust the curves in RGB mode, the curve is represented as a white line.

1. | Click on the line and drag it upward to increase the amount of color saturation or downward to decrease the amount of color saturation in the image.

2. | To set custom points in the curve, click the location on the grid where you want to set a point.

3. | To adjust the custom points, click on the point and drag it to a new position. (You can also use the arrow keys to make incremental adjustments to the position of selected curve points on the grid.)

4. | To remove the custom points, click on the point and then click the red X icon at the bottom of the dialog box.

5. | To adjust the black, white, and gray levels, click the appropriate eye dropper icon and then click inside the image to adjust the levels.

6. | To turn off the curves settings (without removing the adjusted curves), click the Apply Curves check box to return the image to its original settings.

7. | To reset the RGB curve values to the original settings, click the RGB graph icon.

8. | To reset a specific curve, select the curve in the color values drop-down menu and then click the single curve graph icon.

To set the RGB color levels of the image using the histogram sliders:

1. | Open the color values drop-down menu and select a color from the list.

2. | To adjust the color saturation in the shadows, click one of the black-shaded triangles in the lower left corner just outside the graph.

3. | Slide the triangles at the left to adjust the shadow and highlight clipping points.

4. | Slide the triangles at the bottom to adjust the shadow and highlight output levels.

5. | Slide the gray triangle at the bottom to adjust the midtone levels.

6. | To reset the RGB histogram values to the original settings, click the histogram graph icon.

To toggle between before and after histogram modes:

1. | Use the histogram sliders or drag the curve to edit the image.

2. | Click the before and after display icon (up and down arrow).

The display will show the previously saved (or before) histogram. (If you want to compare the look of the edited image to the original image whithout curves applied, click the Apply Curves check box to turn off this feature.)

1. | Click the before and after display icon again to return the control to edit mode so that you are viewing the current (or after) histogram.

To toggle between the large and small display size of the Histogram/Curves dialog box:

1. | Click the change display size icon (up and down arrow).

The Histogram/Curve dialog box display size will change to the larger or smaller display size, depending on which size you started with as your default.

1. | If you change from the larger to the smaller display size, you might need to close and reopen the dialog box to reset the overall size of the dialog box.

To set the histogram to show values for only the cropped area of an image:

1. | Click the check box in the lower left corner of the Histogram/Curve dialog box.

The histogram adjusts to show only the values within the crop frame.

1. | To vewi the histogram for the entire image, click the check box again to turn off the crop-only feature.

To use the In and Out axis controls:

1. | To make adjustments to the position of a selected point on the curve along the x-axis (horizontal), enter a numeric value between 0 and 255 in the In field.

Lower numbers move the point along the x-axis to the left, increasing the brightness of the image. Higher numbers move the point along the x-axis to the right, decreasing the brightness of the image.

1. | To make adjustments to the position of a selected point on the curve along the y-axis (vertical), enter a numeric value between 0 and 255 in the Out field.

Lower numbers move the point downward along the y-axis, decreasing the brightness of the image. Higher numbers move the point upward along the y-axis, increasing the brightness of the image.

To use the overexposure feature:

1. | Click the overexposure warning check box.

2. | In the image view panel, look for magenta-colored highlights on the image to locate the areas that are overexposed.

3. | Use the histogram sliders or drag the curve to correct the exposure levels of the image.

Related Topics

Understanding Basic Image Editing Tools

Understanding Advanced Image Editing Tools