drag0n98 opened this issue on Jul 07, 2002 ยท 11 posts
retrocity posted Tue, 09 July 2002 at 2:27 PM
DragOn98, this method isn't for every type of image, in fact if the image is going to be used on the web, this only adds steps to the process and doesn't really add any benefit. But if you need to retain color as well as sharpen the image try this: Open your image (RGB, CMYK) and convert it to LAB color (Image --> Mode --> Lab Color) In the Channels palette, click on the "Lightness" channel to make it the active one. You'll notice it deselects the other channels. Click on the "visibility" icon (eye) next to the "Lab" channel to make all the channels visible. Open the unsharpen filter dialog box (Filters --> Sharpen --> Unsharp Mask) Since only the "Lightness" channel is active, any adjustment or modification will affect this channel only. A couple of notes at this time: You will be setting the values higher than normal, you can increase the "amount" value by 25-50% and 75-100% higher value in the "radius" slider than you would apply to the image in RGB mode ("threshold" should stay the same). Another thing, a good rule of thumb is "threshold" set to 1 with "radius" set to 2 is better than "threshold" set to 0 and "radius" set to 1. Make your adjustments as needed (for example: "amount" = 100%, "radius" = 1.7 pixels, and "threshold" = 1) When you feel satisfied with correction, convert back to the original color mode (RGB, CMYK) and make anyother modifications to the image. It's probably a good idea to look into more info regarding LAB color mode and how this mode looks at color differently in Photoshop. Hope this helps, :) retrocity