1. Go to Tools / Advanced Editing / Touch Up Object Tool. Select the image and Control/Click or Right Click and choose Edit Image.
2. Once open in PhotoShop, choose Image / Mode / Lab Color. Once converted to LAB, choose Edit/Convert to Profile.
In the profile list, choose the U.S. Web Coated (SWOP) v2 profile (all other settings=default). This will set CMYK ink density to SWOP standards. Select OK.
3. Save the image in PhotoShop, and save the modified PDF.
1. Vector objects in a PDF can be altered by using Illustrator and selecting “Edit Object” and adjusting fills and strokes to less than 320% of ink. The example below illustrates a vector object with a fill in excess of 320 TAC being adjusted to the proper level.
Click here to read Tech Note 56.