resize issues

[jaykappy]

I have a bunch of PDF images that I am trying to convert to jpg and resize....I am doing to this to create thumbnail images for a website, so I want them to be fairly small....

If I do a "convert image.pdf test.jpg " it seems to work fine but the file sizes are still quite large....

Additionally I am doign this conversion to thousands of images and I found MOGRIFY ....if I do "mogrify -format jpg *.pdf" I get a conversion with just the first pages of the PDF and things look good....although the image size is sometimes larger than the PDF itself.

I then tried to resize the image upon MOGRIFY.. "MOGRIFY -format jpg -density 96 -resize 50% *.pdf"

WHEN i do this last one with the density and resize...my resulting JPG images are mostly black and all weird looking....dont know why....
I think some of the PDF images might be off different sizes, but not thinking this should matter.

Anyone have any thoughts? Again looking to take a MUlti-page PDF and convert its first page to JPG to be used as a Thumbnail in a web page...

Thanks

[snibgo]

PDF files are vector format. JPG is raster. If the PDF contains text or vector drawings, a JPG that shows the text just as clearly will be larger.

[jaykappy]

Yea thats my issue then cause most of the images are maps and such from a GIS system.
SO what are my other options? Can I export to something else besides jpg and get the desired result I am looking for?

[jaykappy]

maybe png will work?

[jaykappy]

tried PNG and it seems to work great.....would there be anything else out there that might convert smaller than png?

[snibgo]

Probably not, but you might try TIFF with various compression options. If PNG is good for you but you want it smaller, get hold of program pngcrush.

[jaykappy]

Thanks....very appreciated.