Adjust

This transformation provides a collection of powerful image adjustments that can be applied all at once rather than creating a transformation for each one. The Adjust transformation is intended as a general purpose tool for doing things like adjusting contrast, brightness, color and sharpness for all or part of an image. Combining all these operations into a single transformation makes it easier to understand and control the interactions between the different adjustments. Every operation Adjust can do can also be done using individual transformations, but the Adjust versions are streamlined and incorporate only the most common options.

Amount

The Amount control lets you reduce the effect of the transformation for the whole image or restrict the application of the transformation to part of the image by specifying a mask.

Modes

There are four modes: Curve, Color, Selective Color, and Sharpen.

 Curve -- for black and white images, lets you adjust the brightness curve; for color images you can adjust the color curves.

 Color -- for black and white images, lets you tint the image; for color images, lets you adjust color balance and saturation.

 Selective Color -- lets you make selective color corrections.

 Sharpen/Blur -- lets you perform a gaussian blur on the image or a bilateral sharpen.

Modes are selected via the tabs at the bottom of the dialog box. Each mode has its own settings and controls as described below. You can toggle the effects of any of the four modes on the output image using the mode tool bar. When a button is depressed, the corresponding mode is enabled and its operations are reflected in the output image. When a button is raised, the mode is disabled and its contribution to the output image is suppressed.

Adjust performs operations on the input image in same the order they appear in the tool bar.

For color images:

Color Curves

Color Balance

Saturation

Selective Color Correction

Sharpen/Blur

For black and white images:

Brightness Curve

Tint

Selective Color Correction

Sharpen/Blur

Probes

In Curve mode, clicking on the input image displays a red marker on the curve -- shift-clicking on the input image creates a new control point on the curve corresponding to the brightness at the point you clicked.

In Color mode, if the input image is color, clicking on the input image sets the color cast -- if the input image is black and white, clicking on the input image displays a red marker on the color line, and shift-clicking on the input image inserts a new control point in the color line.

In Selective Color mode, clicking on the input image creates a new control point.

The probe is disabled in Sharpen mode. Use the Settings Menu to set the probe size (see below).

Probes act on the result of the previous operation (or on the input image if there is no previous operation). Thus clicking on the input image in Selective Color Correction mode picks up the color from the image with Curve and Color mode settings applied.                                                   

 Curve Mode

Color Space and Channel (color images only)

These control lets you select the HSV, HSL or RGB color space and the individual color channel you want to adjust. In the RGB color space, you can adjust the individual red, green and blue channels or you can select All which displays a combined histogram and applies the same curve to all three channels.

Curve

The curve control lets you adjust the selected channel (or the brightness for black and white images). You can make the curve larger by resizing the Adjust dialog box.

 Color Mode

For color images, this mode lets you adjust the color balance and saturation of the image.

Color Cast

The color cast control lets you select a color cast to add to or remove from the image. To select a color cast, click on the color wheel. To make it easier to make fine adjustments, you can zoom or scroll the color wheel. Also the color wheel can be made larger by expanding the Adjust dialog box.

Add/Remove Color Cast

Add Color Cast -- the selected color is applied like a color filter over the image. For example, to make an image warmer, select an light orange; to make it cooler, select a light blue.

Remove Color Cast -- the complement of the selected color is applied, make colors in the image that match the color cast become neutral. This is useful if there is something in the image that should be neutral such as the whites of the eye -- click on it in the input image and the necessary filter will be applied automatically to restore the color balance.

Saturation Color Space

You can adjust saturation in either the HSV or HSL color space. The differences when adjusting saturation between HSV and HSL are subtle except in extreme cases.

Saturation

This slider lets you increase or decrease the saturation of the image. It preserves fully saturated and fully unsaturated colors and acts mostly on partially saturated colors.

For black and white images, this mode lets you colorize the image as in the Tint transformation

Color Line

The color line control lets you assign different colors to different gray levels.

 Selective Color Mode

The Selective Color Correction control lets you apply color and brightness corrections based on the hue and saturation of the image. You make the color wheel larger by resizing the Adjust dialog box.

 Sharpen Mode

Operation (Blur/Sharpen)

This control lets you select whether you want to blur or sharpen the image. The controls below it change depending on the option you select.

                                           Sharpen                                                                                                     Blur

Sharpen Controls (same as Bilateral Sharpen)

Halo Limit

This control has two sliders for limiting light and dark halos. Halos are sharpening artifacts and appear as light or dark areas around prominent edges in the input image. If you notice such a halo, reduce it by moving the appropriate slider to the left until the halo is no longer noticeable. Settings in the range of 5 - 15% are typical.

Blur Radius

The Blur Radius slider controls the degree of blurring performed using a bilateral technique that blurs detail but not across edges. This helps reduce halos and other sharpening artifacts.

The Blur Radius slider determines the scale of detail that will be sharpened. Small blur radius values sharpen fine detail while larger radius value work on larger image features such as clouds. It can be useful to use multiple sharpening passes with different radius settings.

Blur Threshold

This slider adjusts the threshold for inclusion in the blurring average. A threshold of zero reverts to simple sharpening and can result in halos around edges in the result image. Too high a threshold eliminates the blurring effect and thus results in little or no sharpening. A value around 30% to 40% usually works well for small blur radius settings, while smaller values work better for large blur radius values.

Sharpen Factor

The greater the Sharpen Factor, the more pronounced the sharpening effect. At 0.00 you get the blurred image; at 1.00 you get no sharpening; at higher values, you get increasing amounts of sharpening. Typical values are in the range from 1.25 to 2.50.

Sharpen Threshold

The Sharpen Threshold can be used to reduce the tendency to increase noise in the input image. When sharpening an image, the input image is first compared to a blurred version of the input image. If the absolute value of the difference is less than the threshold, no sharpening is done. Thus, a threshold of zero causes the entire image to be sharpened (except for regions partially or totally excluded by a mask). Large threshold values cause the sharpening to be applied only to very strong and sharp edges. A value of 0.00% yields full sharpening; higher values eliminate sharpening of increasingly coarse detail.

Blur Controls

Blur Radius

This slider determines the amount of blurring. The results are the same as performing a Gaussian Blur.

  Base Histogram on Masked Area Only

The curve control displays both a histogram and a curve. If this button is raised, the histogram is based on the entire input image. If depressed, the histogram is based on just the currently masked area as defined by the amount mask. If there is no mask, the histogram is based on the entire image. If there is a mask but it is entirely black, the histogram is not displayed. Changing this setting only affects the way histograms are displayed and has no effect on the output image.

If you are using a mask to limit the action of the transformation to just part of the image, this control lets you see the histogram of just the part you are adjusting.

Tips

You can create a library of presets by saving Adjust settings in named files via the standard Settings Menu.

You can apply settings to an image with a brush by creating an amount mask and using the Mask Paint tool. Or you can use the Freehand Outline Mask tool followed by the Blur Mask tool to create a soft-edged mask to apply the effect. You can then adjust the strength of the effect using the Amount sliders.