08-30-2008, 12:41 AM
The first number, the Amount, is simply "how much" sharpening. Should be pretty straightforward.
The Radius roughly means "how big" or put another way, how big a bite to take at a time (literally it's the number of pixels in a radius used by the filter to do its edge enhancement). The radius needs to be adjusted based on the size of the image. The larger the image, the larger the radius should be and vice-versa. For an 800 pixel image, you would probably want a radius of about 0.3 to 0.8 (adjust for personal preference and image content). For a 3000 pixel image, you might want something around 1.5, etc. If your radius is too large for the size of your image, you will start to see outlines around all the edge details.
Finally, the Threshold roughly means how big does the detail need to be to not be overlooked. The bigger the number, the bigger the feature must be to be sharpened--or everything below the threshold is not sharpened. You generally use the threshold to keep from sharpening noise.
The Radius roughly means "how big" or put another way, how big a bite to take at a time (literally it's the number of pixels in a radius used by the filter to do its edge enhancement). The radius needs to be adjusted based on the size of the image. The larger the image, the larger the radius should be and vice-versa. For an 800 pixel image, you would probably want a radius of about 0.3 to 0.8 (adjust for personal preference and image content). For a 3000 pixel image, you might want something around 1.5, etc. If your radius is too large for the size of your image, you will start to see outlines around all the edge details.
Finally, the Threshold roughly means how big does the detail need to be to not be overlooked. The bigger the number, the bigger the feature must be to be sharpened--or everything below the threshold is not sharpened. You generally use the threshold to keep from sharpening noise.