PDF files can easily be opened in Photoshop, from there all you need to do is save out as a JPG by selecting "Save as..." from the "File" menu, and changing the file type to JPG/JPEG before saving.
To convert 12 JPEG images into a single PDF file, you can use online tools or software like Adobe Acrobat. Simply upload the JPEG images, arrange them in the desired order, and then save the file as a PDF.
Unless the PDF is <15 pages long, the JPEG will be smaller. If the PDF is really short (i.e. a 3-page restaurant menu), then the PDF will be smaller.
There are many applications which will do this, including Adobe Acrobat, the original PDF document creation software. Free software that does this includes PDFCreator and CutePDFWriter, which you can find using any web search engine. Note that what you are actually getting it simply a (potentially even more distorted, due to compression) copy of the jpeg file encapsulated within the pdf file.
No, Adobe Reader will read PDF files, while Adobe Acrobat can create and edit PDF files. Adobe Reader is just a free PDF reader, but Adobe Acrobat Pro/Stand is much more powerful to deal with PDF files, will help to create, edit and convert PDF.
jpeg is standard, extension or format for photos and doesn't matter where is created, you can print those photos, share on web, email to friend, put it in pdf or word document, power point presentation...
your not trying hard enough
I want to convert JPEG to PDF because what I've scanned is all text, and is illegible to the receiver, it's blurry.
You need to open the pdf in a program such as Adobe Illustrator or Photoshop. Usually when you open a pdf it is in adobe reader. The reader program is only for looking at a file and can't edit it. If the pdf file you need to re-color was created in Illustrator and the images are vector, they will be easy to re-color
Adobe PDF readers are generally free to download from the Adobe website. The best available reader is their latest release, the Adobe Reader XI (11.0.03).
You must have (buy ?) Adobe's PDF writer.
common attachment file types are .pdf (adobe reader), .doc (microsoft word), .jpg (jpeg image), and .zip (compressed files of any file format).
You can download Adobe PDF writer off the Adobe website. You can also download all the other Adobe services that you need on their website although not all of them are free.