Yes—approximately. There isn’t a perfect “post-process focus peaking” for every image, but you can estimate sharp areas by detecting strong high-frequency detail.

Common approaches mentioned:

• Use a high-pass filter (available in Photoshop and similar editors). Sharp edges will stand out more than soft areas.
• Use edge-detection methods such as a Laplacian-of-Gaussian filter, then take the absolute result, threshold it, and optionally clean it up with a median filter.

In practice, this highlights areas with strong fine detail, which often correspond to in-focus regions. However, it’s not foolproof:

• High-contrast blurred edges can still be flagged.
• JPEG artifacts can create false positives.
• Texture and contrast affect the result, so “sharp-looking” output is only an estimate of focus, not a definitive depth-of-field map.

So yes, image editors and image-processing tools can do a useful approximation, but the result should be interpreted as sharpness/edge strength rather than a precise focus indicator.