Sounds like you are possibly inserting the images then scaling them down to fit specific dimensions? If so, that's your issue. The browser does an awful job of scaling. You will be much better off by doing a couple of things.
1. Do as much as you can to properly size the image as small as you can before you even capture.
2. Use a dedicated image manipulation application to rescale the image and save it at the smaller size.
Paint Shop Pro
Thanks, Rick. That really helps but when I scale the image, now it looks good on chm, but the quality on PDF is not that good anymore
Sounds like you need to use two versions of the images. Then apply Conditional Build Tags to them. One for Print and One for online. Actually, those are the exact two tags RoboHelp creates for you by default.
Then when you create a PDF, you exclude the images tagged with Online. When you create the online, exclude the images tagged with Print.
I might do that as last resort. It would be tedious though because my document has lots of images .
Personally, I would recommend using gifs. Make sure you create your gifs from a good a starting point as possible. What we do here is capture using paintshop pro at high quality, then save as gif. We've found this works well in web, pdf, chm and web help formats..
Hi, thanks for your suggestion. I will try that as well.
Out of curiosity, why the preference for GIF?
Myself, I like PNG format...