Scanning photos from books, magazines and newspapers often results in an unsightly interference pattern called moire. If your scanner doesn't offer descreening, it's not too hard to remove yourself.
Difficulty: Average
Time Required: 5 minutes
Here's How:
- Scan the image at a resolution approximately 150-200% higher than what you need for final output.
- Go to Effects > Noise > Remove moiré.
- Set the amount according to the quality of the souce. Typically scans from newspaper will need a higher amount, magazines need a middle amount and books can get by with a lower amount.
- If you are working with a large file and your system doesn't have a lot of ram, you may wish to optimize for speed in the Remove moire dialog.
- In the decrease resolution section, change output to the desired final resolution.
- Click preview and adjust the amount if neccessary.
- Go to Effects > Sharpen > Unsharp Mask.
- Exact settings will depend on the image resolution, but these settings are a good starting point: Percentage 50-100%, Radius 1-3 pixels, Threshold 1-5. Click preview and your eye as the final judge.
Tips:
- Using the lowest amount you can get by with in step 3 will retain more clarity in the final image.
- Using Effects > Noise > Median and then resampling may produce better results than using the Remove moire effect.
