Adjusting contrast is a basic yet powerful image processing tool. Astra Image extends this by allowing you to adjust contrast at different scales. This means that you can change the contrast of small, medium and large details independently. The result is an extremely powerful tool that can bring out details to an amazing extent in almost all kinds of images.
Global, Shadows, Midtones, Highlights: these buttons allow you to selectively apply the multiscale contrast adjustment. When the Global button is selected, the entire image is processed. When the Shadows button is selected, the adjustment is only applied to darker areas of the image. Midtones and Highlights operate the same way, adjusting only the mid-range areas and bright areas of the image respectively.
Small Detail: this sets how much contrast enhancement is done on small details in the image.
Medium Detail: this sets how much contrast enhancement is done on medium details in the image.
Large Detail: this sets how much contrast enhancement is done on large details in the image.
Reset All Adjustments: if you click this button, all the settings are reset to their default values.
Strength: this setting adjusts the strength of the overall effect, without affecting the balance between the small, medium and large detail settings.
Protect edges: sometimes sharp edges can be over enhanced, making them look too bright. When this option is checked, sharp edges are protected from being over enhanced resulting in a much more natural looking image. It is usually best to leave this option checked.