Use one of the modes in AKVIS Enhancer to improve a photo. For further image correction you can use the Post Processing tab. It is available only in the standalone edition because any image editor offers these features, so there is no reason to use this section in the plugin.
The Post Processing tab contains a Histogram and four parameters: Brightness, Contrast, Gamma and Saturation.
A Histogram is a graph that shows the tonal range of an image. On the horizontal line the brightness values are set - from the darkest to the lightest. The vertical line sets the number of pixels having this lightness value.
Below the histogram there are three sliders that can be moved to change the image contrast.
The extreme point on the right end represents pixels having the maximum brightness (white points). If the histogram does not have such pixels, the image does not contain any white points. If we move the white slider to the left, the point against which the slider is located will assume the maximum brightness (255) and the pixels having this value will become white. The brightness of other pixels will be re-calculated accordingly. The image will get lighter.
The extreme point on the left end represents pixels having the minimum brightness (black points). If the histogram does not start at the left end, the image does not have any black pixels (brightness = 0). If you move the black slider to the right, the point against which the slider is located will assume the minimum brightness value. As a result this tone will become black, while other pixels will be re-calculated accordingly. The image will get darker.
The middle slider defines the tone of the image that will have the brightness of 128 (middle-gray tones). If you move the slider to the left, the mid-gray tones get lighter; if you move the slider to the right, the mid-gray tones get darker.
Near the histogram there is a drop-down list with image channels (RGB, Red, Green, Blue, Colors, Luminosity). It is possible to adjust every channel separately or correct a combined channel.
The Post Processing tab also contains parameters that correct the brightness and contrast of the image, make gamma-corrections and change the saturation of the image.
As you adjust the settings in this tab, the processing is started automatically. The result is shown in the After tab.