What is edge detection

Use edge detection

Günter Schuler

Use edge detection

Adjust mask with edge detection

To do this, select the "Normal cropping" layer, hide the other two layer copies and select the "Normal cropping mask" channel with the current layer mask in the "Channels" window. The "Improve Edge" command can now be activated directly via the "Masks" window by clicking the "Mask Edge" button. The core and pivotal point of the refinement that follows are the radius slider in the upper "Edge detection" field and the Smart Radius click box directly above it (see figure below). In order to create the finest possible transitions in the hair areas, the radius slider is set to a maximum value of 250 pixels. Photoshop displays the new edge transitions immediately after the calculation.

Tip: If you press the X key, Photoshop temporarily switches to the image view with the current layer mask. Intermediate result: The newly created transition areas still need a slight contrast enhancement in the dark outer areas. The transitions in the hair areas, however, are as natural as in the picture itself.

Apply edge detection

The same procedure is now carried out for the two levels "Wide clearance" and "Narrow clearance". Important difference here: In order to create a wide or a narrow mask, the edge treated with edge detection is also shifted into the positive or negative area. Function: The "Move Edge" slider in Improve Edge. The values ​​are chosen depending on the picture; in the example 30 pixels each. Intermediate result of steps 5 and 6 after a final contrast correction in the individual layer masks: Three cut-out layers with slightly varied masks.

Show layers in the background

Since the background of the original picture is clearly darker, a synchronization between the cut-out motif and the new background is absolutely necessary. The preparation allows you to try out the different level variants and combine them with one another. Due to the light background, the following combination produces the best results: Upper layer with a narrow mask ("Cropping narrow") displayed normally, middle layer with a normal, ie slightly wider, mask displayed in "Soft Light" mode. The assigned filling method ensures a mixed calculation between the white background and the other cropping variant. The result is a very realistic overall presentation.

Finalize result

A few details can still be optimized - especially the fine veil to the left of the face. The method of choice is a slight contour enhancement using a layer effect: The "Exemption normal" layer is given a soft drop shadow with one pixel spacing, trapping and size for contour enhancement. Last but not least, you could now consider whether you should also optimize the colors and contrast of the entire assembly - for example, using a setting level for gradation curves with a lightening curve.