Message:

<p>[QUOTE=&quot;Leadfoot, post: 1035070, member: 2972&quot;]Those are sharpening artifacts (white halos around sharp contrast edges) and jpeg compression artifacts (field smoothing/jagged edges).</p><p><br /></p><p>Are you suggesting that this is evidence of image doctoring?</p><p><br /></p><p>It certainly isn&#039;t in my book.</p><p><br /></p><p>Here&#039;s how to reproduce the effect in 4 steps.</p><p>1. Take coin photo.&nbsp; Make sure there&#039;s a feature (Like Lincoln&#039;s nose) at a 45 degree angle to vertical or horizontal (this will ensure you get a jagged edge).</p><p>2. Apply sharpening of 150%, 1, 10. (this will ensure you will get a halo around an edge and a relatively blurry rest of photo)</p><p>3. Save as JPG at medium compression. (this will smooth the fields further relative to contrasty portions of the photo)</p><p>4. Reopen the JPG file and compare that image at 800% to the image you provided.&nbsp; (this will expose all the defects described above)</p><p><br /></p><p>Have fun....Mike</p><p><br /></p><p>p.s. be careful when you blow up digital photos -- they exhibit all sorts of odd effects introduced in the capture and post processing, even something simple like saving.&nbsp; These effects are enhanced by magnification above 100%, and are NOT necessarily evidence of nefarious intent.[/QUOTE]</p><p><br /></p>

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in