Noise/pixelation in WebHelp .JPG images

Hi,

Using Robohelp 7 and having trouble with some pixelation/noise in documents. Basically, we have images of letters, and on the letters, everywhere there is black text (like the person's name, address, title, etc) there is a surrounding field of pixelated dots all around it. I have gone in with both SnagIt and Photoshop and by hand, erased pixel-by-pixel this "noise." It looks great on the screen (in those software programs) but then the next time I open it in RoboHelp WebHelp (or even HTML help), all that noise is back, as if I didn't do a thing. It also re-appears the next time I open the .jpg image in the photo editors. What am I doing wrong? It's true that these images WERE .pdfs, which were then re-saved as .jpgs to put into RoboHelp. I am extremely picky and think the noise looks terrible. And even though I could spend DAYS erasing the pixels, they come right back! Would really appreciate assistance here. Thanks,

Heather

Raleigh, NC