Adjust filters

Adjust color



Adjusting the color of an image lets you greatly alter the mood. Here, a cloudy mountain scape is turned into a bright and warm late afternoon.

In the default mode, Multiply, the colors in each channel are multiplied by the value of the slider. The ranges are between 0 and 200%, meaning each channel can be up twice as intense.

By switching to the Add tab, you can alter the channels by adding a value to them. This can be used, for example, to add a blue cast to an image to simulate old film, or other effects.

Clicking the Animate button allows you to apply the color changes to an entire animation, if one is initialized.



The Advanced tab lets you make color changes to shadow, mid-tones, and highlight tones independently. Say you want to make the shadows in am image deep blue. You could select the “Shadow” option at the bottom, and reduce the red and green sliders, while turning up the blue slider. The color changes would only be applied to the lower 1/3 of the value range in your image, which would most likely be the shadowiest parts in your image.






Adjust value



Value is the darkness or lightness, or level of light. You can alter the value of your image, increasing or decreasing brightness, or contrast.

The left part of the panel is the histogram. It measures the quantity of pixels using various levels of brightness. As you can see indicated, the graph is measured from the darkest levels (left) to lightest levels (right). The height of the graph indicates the number of pixels using those levels.

The value slider adjusts the value of your image by multiplying the value of each pixel by the value of the slider. The center position is 100%, or no change.

The brightness slider alters the value of your image by adding the value of the slider to each pixel.

The contrast slider alters the contrast of your image by stretching or compressing the histogram.

Gamma lets you adjust your image for display on different types of monitors or output devices. A composite (television) monitor, for example, uses a non-linear gamma, and should be taken into account.

Clicking the Animate button allows you to apply the color changes to an entire animation, if one is initialized.


 

Threshold



The threshold filter converts an picture to an image with black or white only. The level indicates what brightness level will be the median between black or white. The invert check-box reversed the effect.

Threshold can be useful for creating images similar to wood carvings, or for simplifying specific shapes.

Clicking the Animate button allows you to apply the color changes to an entire animation, if one is initialized.


 

Saturation



The saturation filter lets you reduce the saturation in your image. This can result in a grayscale image, or an image with less intense colors.

Saturation can also be increased to create an image with more intense colors than the original.

Clicking the Animate button allows you to apply the color changes to an entire animation, if one is initialized.

Also see the Hue/Sat/Value filter.


 

Hue/Sat/Value



The Hue/Sat/Value filter lets you alter several color characteristics at once.

Hue is the property of colors by which they are named, such as red, yellow, blue, etc. Hue is often represented as a color wheel, or in a rainbow. Changing the hue effectively rotates all the colors in an image around a color wheel.

Saturation is the intensity of a color (or difference from gray). You can decrease or increase the overall saturation of an image, making it more or less colorful. Many photos from digital cameras can benefit from a slight increase in saturation to bring out the colors.

Value is the darkness or lightness of a color. Changing the value will make an image lighter or darker.

Clicking the Animate button allows you to apply the color changes to an entire animation, if one is initialized.


 

Auto balance



Much like the 'auto' controls on a camera, the Auto balance filter lets you adjust the final appearance of your image to correct for improper lighting conditions or settings when the photo was taken.

The filters lets you place a small “window” over your image, and a sampling of color and brightness will be taken from this window. These samples will be used to determine the best way to re-balance the image.

There are two modes, exposure and white balance. The exposure mode alters an image to take advantage of the full dynamic range available (0-255 levels) The white balance mode also accounts for color, and adjusts colors to look like the image was taken with a white light source. It assumes your window is focused over an area that contains colors that should be white.

Clicking the Animate button allows you to apply the color changes to an entire animation, if one is initialized. Each frame will be value or white-balance corrected independently. This might be useful for correcting images that were taken as part of a time-lapse recording. Each frame in a time-lapse recording will likely have different exposure and color levels, due to changing atmospheric conditions.


 

Tint



Tint, or a shade of color, can be applied to an image to alter its mood. The tint filter presents a color wheel where you can select a color to tint your image with. Colors toward the outside of the wheel will apply a more extreme tint.

Clicking the Animate button allows you to apply the color changes to an entire animation. This could be a quick way to make a daylight shot look like it was filmed at night, or at sunset.






Value only contrast



This filter lets you change the contrast of an image without altering the color intensity. In a traditional contrast adjustment, red, green, and blue levels are multiplied by a specific factor relative to a center value (generally 128). This increases or decreases the value, but also increases or decreases the intensity of color.

Value only contrast works only on the value channel of the image to avoid this problem. Value only contrast can produce a highly contrasty image with a psychologically different feel to it than regular contrast adjustments.

Clicking the Animate button allows you to apply the color changes to an entire animation.



Adjust levels



Sometimes you want to limit or clamp part of the dynamic range of values within an image. “Adjust levels” lets you do this easily with a simple set of arrow controls.

The arrows on the bottom act as a contrast adjustment, where you can independently select the upper and lower levels you want.

The arrows on the top let you clamp the levels in your image. For example, you could clamp the lower levels, so that no value under 40 will appear in your image.

Clicking the Animate button allows you to apply the color changes to an entire animation.




Adjust curve



Sometimes you want to “remap” the values in an image to create specific effects. The Adjust curve filter let's you do this by drawing curve to represent the new intensities. You might do this to brighten shady areas in a photograph, or to deepen a bright sky, or to better balance the tones in an image.

The diagonal gray line going from the bottom-left to the upper-right represents the original grayscale levels. The line goes from 0 to 255 over 255 pixels, so it can be thought of as a literal representation of the original “value map.”

Click to add a new point to a curve you want to edit. Right click on a point to remove it. If your curve gets to complex to work on, you can reset it.

Clicking the Animate button allows you to apply the color changes to an entire animation.





Color FX filter



The Color FX filter lets you make dramatic changes to the tone of an image without effecting the overall color scheme.

It works by splitting an image in to separate value, hue and saturation channels.

The value channel is created (in the same way as “Expose through lens”) by exposing the red, green, and blue channels as if through a color filter. The color filters out some of the colors in the image, while intensifying others. For example, a blue sky may become very deep, or very bright, depending on what color is used to filter the channels.

The value channel is then re-combined with the original, unchanged hue and saturation channels, to create a new RGB image.

Here, the red of the apple is greatly deepened or lightened depending on the filter color chosen, without effecting the color (hue) component of the image.





Adjust all



The “Adjust All” filter lets you adjust a number of parameters, all at the same time. The adjust all filter is based on a color matrix, so most of the parameters are handled by a single function, internally speaking. The Hue and Gamma parameters are implemented separately because they are non-linear adjustments.