Colors

Color

> As much as Exposure, Color correction is another very important task when improving digital pictures.

> Besides the automatic corrections found under the menu: Auto, you can access the manual corrections from the menu Color:

> Color > Hue - Saturation

> Although usually it's not convenient to work in these color spaces, there maybe case when you want to achieve some special color effect, for which Hls and Hvs can be very useful.

> For example we may want to shift the hue of the whole picture or just of some colors inside the picture. Hls and Hvs can be used in conjunction with a color mask to selectively change/replace one color.

> To do this find the Color Mask Selector, in the dialog:

> In the following picture after we select a magenta color mask, we apply a hue shift selectively:

> Color > Saturation - RGB

> In Focus Photoeditor Saturation can be adjusted separately for each channel but quite often you will adjust all channels by the same amount. This is ensured by the "Linked" option.

> Below is an example of increasing saturation:

> Before | After

> Color > RGB Balance

> You can balance colors in a picture, by adding or subtracting a given amount to each color channel. An internal balancing algorithm allows to preserve the overall luminosity of the picture.

> In color balance, adding an amount to red is equivalent to decrease the cyan of the same amount. Same for other coupled colors: green-magenta and blue-yellow.

> You can also choose to work on the full tonal range or just on shadows, midtones or hilights. Example of RGB balance is presented below:

> Before | After

> Color > CYM Balance

> This is equivalent to RGB balance, but you can think in terms of Cyan-Magenta-Yellow rather than Red-Green-Blue

> Color > Color Temperature

> This tool simulates the different color temperatures from the warmest to the coldest. For example you can simulate the condition of light in different hours of the day (colder in early morning, warmer at noon, very warm on a sunset) or of the seasons (winter, summer etc..)

> Color > Calibrate Colors

> This is a tool to remove color casts, manually with the help of a referring color. Select with the pipette the reference color that you think contains a color cast. Then Select the destination color, that is the color into which the source should be changed. It is recommended that you first copy the source color into the destination, and then adjust it opening the color dialog. If you want completely neutralize a color cast then click the "copy to gray" button.

> After you have set the source and destination colors the picture will be adjusted and cast removed.

> A tip to use this tool: first try to understand which kind of color cast is in the picture (example green, yellow, magenta..) then with the pipette select the source color of some object you know the real color of. For example the asphalt in a street should be gray or the snow should be white, etc..

> Color > Color Replacement

> The color replacement allows to select a source color and convert it into a destination color, using a tolerance. This tool is very easy to use: you just have to select with the pipette a color from the picture, choose the replacement color and increase the tolerance until you like the final result. Here is an example:

> Color > GrayScale

> This tool lets you create black and white images, like with traditional photo techniques. You can choose which amount of red, green and blue channel should be used to create the black and white picture.

> Color > Negative

> Creates a negative of the picture.

> Color > Optimized Palette

> This lets you fix the number of unique colors which represent the picture. The program will choose a representative sample of colours in the number you specify and will elaborate the picture based only on these colours.