The Mask tab sheet let you remove the effect from image areas of a certain color as well as adjust the edge mask which is used to balance the sharpening or blur effect.
The Color Protection group lets you protect up to three colors from being sharpened. This feature does not work with grayscale, CMYK and Lab images.
In the right image the blue areas were protected from sharpening .
There are three control pairs consisting of a color box and slider. The color box defines a color. The sharpening effect can be removed from image areas of that color by using the slider. Clicking on the appropriate color box activates the color picker tool and lets you click on the preview to select a color. Clicking on the color picker tool above the preview automatically displays the Mask tab sheet. Double click the color box to display a color dialog.
The higher the value of the slider, the more the effect is removed from the image area of the defined color. Higher values also increase the image area from which the effect is removed. For example if you select a yellow color and use a slider value of 80, image areas of a orange or yellow-green color can be affected. So use a low as possible but high enough slider value to get the best effect.
By default the first color box offers a brown color which represents skin tone, the second color box contains a blue color for sky areas and the third color box lets you remove the effect from tree/plant areas. You can set these colors again if you click on the arrow-down button and select the first three menu items. The forth and fifth items set the first color box to a brighter or darker skin color.
The edge mask is basically a greyscale image that defines the edge and surface areas of the image. It is generated by calculating the difference between each pixel value and its neighboring pixels. Strong differences are edge areas and weak differences represent surfaces. The edge mask is used to apply different sharpening or blur effects to edges or surfaces thus creating a more balanced result.
When using the Dual Radius method on the Manual tab sheet the edges are affected by the controls of the Edges group and the surface areas are controlled by the Surface group of the Manual tab sheet. For the other two methods the sharpening intensity of the surface areas is controls by the Surface slider.
The right image shows the edge mask that was made visible with the N button.
The N and P buttons let you view the edges and surface areas as a greyscale image. N stands for negative and P for positive. Activating the N button displays the edges as white and the surfaces as black. With the P button it is vise versa. Both options let you visually adjust the edge mask that is used for sharpening or blurring. Don't forget to switch off the N or P button by clicking on it again, otherwise will produce a special effect after clicking OK. There are similar buttons called C1, C2, O1 and O2 on the Effects tab sheets. These produce similar effects, but these overlay the image with the edges.
Clicking the arrow-down button displays a menu with various options. The "Default" menu item restores the default edge mask settings. The "Stronger" and "Weaker" option make the edge mask stronger or weaker. "Version 1 Defaults" reproduces the edge mask setting of FocalBlade 1. "Full Surface" makes the edge mask completely black, which means that the surface settings on the Manual tab sheet are applied to the whole image. The "Plain Edges" recreates the original edge mask without any processing.
The Intensity slider lets you increase the intensity of the edges. High values also increase their size. At a value of 255 most of the surface areas have vanished from the edge mask whereas low values only weaken the intensity of the edges. At a value of 0 the whole image will be considered as "surface" by FocalBlade, so the settings of the Surface tab will be applied to the whole image and the settings of the Edges tab won't be used at all.
Activating the check box at the left hand-side of the Intensity slider automatically assigns a value for the Intensity slider, which amplifies the edges without diminishing the surface areas.
The Width slider lets you increase the size of the edges by blurring them. This avoids that the edge mask is too hard thus omitting hard transitions between the edges and surface when sharpening the image. It is best not to choose a too small or too large value for this slider. Best keep it at the default value if yo have no reason to choose a different value.
To filter out this noise from the edge mask, you can use the Remove slider. It will help you to remove edges that are the result of low luma noise. Please be careful to not assign a too high value to this slider, otherwise you may also clip essential edges and thereby prevent them from being sharpened. For images without noise you can use the Remove slider to shrink the edge areas.
The Equalize slider amplifies the weak areas of the edge mask, so that some surface areas are turned into edges. At a value of -100 many image areas are not sharpened that much, because the usually weaker surface sharpening is applied. This was the default in Version 1 of FocalBlade. With FocalBlade 2 the default value is zero which makes sure that weaker details are sharpened stronger.
Values below zero of the Contrast slider decrease the contrast of the edge mask. So the difference between edges and surface areas is reduced. Positive value on the other hand increase the contrast, which makes edges as well as surface areas more defined.
The Lightness slider basically darkens or brightens the edge mask. At a value of 100 the whole image will be considered as edges, which means that the Edge settings on the Manual tab sheet will be applied to the whole image. A value of -100 will result in surface areas only, so the Surface settings will only be applied to the image. This slider can also be used to balance the edge and surface settings.