Adjusting Image Colors

Photovault has 2 complementary methods for adjusting image colors, brightness and contrast:

• Color curves, familiar form image editing programs like Photoshop or Gimp, can be used for all images
• For raw camera files, these can be set already during raw conversion

These methods are complementary. Raw images have much larger dynamic range than normal images, so during raw conversion some details are inevitably lost. On the other hand, color curve tool gives more detailed control to particular tone ranges as well as possibility to change color saturation. With raw images you will usually get better result if you first change the raw conversion parameters so that you get as close as possible to desired result and do only fine tuning using color curves.

Color Curve Tool

Start adjustment by selecting the image or images you want to modify in thumbnail view. Select "Adjust Colors..." either from pop-up menu, Image menu or toolbar.

Color adjustment dialog has 2 pages: one for raw conversion and another for color curve settings. In the color curve page select first the channel you want to modify. After that Photovault displays the current curve used for adjusting that channel.

Curve Display

The curve display show mapping from source image values (horizontal axis) to final image values (vertical axis). The mapping used for selected channel is shown with a thick line, the other channels are shown with lighter lines. Behind the lines there is a histogram that shows relative amount of source image pixels having each value.

Changing Curves

The shape of the curves is determined from control points (shown as small rectangles). To move a control point just drag it to a new location.

To add a new control point press mouse button anywhere on top of the curve and drag.

Saving Changes

When you are satisfied with the changes save them by pressing "*Apply*" or "*OK*"

• "Apply" button saves the changes but does not close the color adjustment dialog
• "OK" button closes the dialog window after saving changes

If you want to discard changes and start over, press "*Discard*". Photovault reverts to the last saved color settings.

Value Curve

Value curve controls all color channels simultaneously. With it you can adjust image brightness and contrast.

Color Channel Curves

The color channel curves adjust values of a single color channel at time

Saturation Curve

Saturation curve adjust the saturation of image in IHS color space. Increasing slope of saturation curve makes the image more saturated, decreasing the slope has an opposite effect. Setting all control points to lowest value makes image black&white.

Saturation curve gives you much more control over color saturation and vibrance than mos timage processing tools. For example, if you increase saturation a lot, some of the most vivid colors can "burn" because the values cannot be represented by image color space. You can avoid this by adding a control point and saturating only the subtler colors.

Linear saturation increase

Saturation increased for subtle colors only

Adjusting Multiple Images

As with most Photovault controls, you can adjust colors of multiple images at once, but Photovault won't display a preview. However, all of the curves used for selected channel in the images are show with light grey line in the background.

Let's assume that you have several images from the same shooting and you want to apply the same color correction to all of them. An easy eway to do this in Photovault is:

1. Select one of the images and adjust its colors. Save the result by pressing "*Apply*"
2. Select all of the images you want to adjust. Photovault shows the adjustment done in step 1. with gery line.
3. Change all color channels so that the thick line matches the light grey line. Press Apply
4. Now Photovault has applied the same color correction for each of the images. You can see the result in thumbnail view and check each image individually by selecting it.