I have a batch of PNG files that I need to convert to JPEG. I'm looking for a free trustworthy utility that will give me the most optimal possible JPEGs.
I've found some paid utilities and i HAVE Photoshop, but I want something dedicated that is made for the task and I dont want to accidentally download spy ware.
I'm really surprised not to find this question already on StackOverflow, but please point me in the direction of any similar questions if they exist.
One word: ImageMagick.
Not sure about if it generates the absolute smallest JPEGs you can get, but it's certainly good and would be my first choice.
Imagemagick (http://www.imagemagick.org/script/index.php) can do batch conversion of images.
mogrify -format jpg *.png <= Converts all png files to jpg
The ImageMagick convert utility should do everything you require. There are a number of options which you can use to control the JPEG output quality.
IrfanView is another option. It has a "Batch Convert/Rename" feature, but it's a Windows-only GUI app.