The History Brush allows you to restore any part of an image to its original state.
The basic tool settings are shown in the Tool Options panel above the Image Window or by right-clicking on the image. To display the full list of parameters, press the tool icon in the Tool Options panel or use the F5 key. To specify the parameter settings, enter a numerical value in the parameter’s field or use the slider.
Element - in the drop-down list, select the type of the basic element of the brush: Ellipse or Select Shape.
Size (1-5000). The maximum width of a line made by the brush (in pixels).
Hardness (0-100). The degree of blurriness of the brush’s edges. As the value of this parameter is increased the brush’s edges become harder. At values near 100% the border between the brush’s edges and the background is very distinct; at lower values the transition between these areas is smoother.
Strength (1-100). The degree of restoration to the original state. At lower values there will be less restoration and more blending with the effect; at values near 100% the original condition will be restored more completely.
Fill (1-100). The parameter affects the intensity of the Strength parameter in a single brush stroke. At the value = 100%, the Strength parameter is not affected.
In addition to the above-mentioned parameters, you can adjust the advanced settings.
Press the Default button to set all settings to their default values.
To draw a straight line, first specify the starting point with the left mouse button, then, while keeping Shift pressed, move the cursor to the desired end point of the line and release Shift. If Shift is not released, a new line will be drawn to each point where the mouse is clicked.