Adobe InDesign/EXPORTING A PDF WITH RASTERIZED CONTENTS
Graphics101 wrote at 2016-09-10 17:22:19
The above answer has some things wrong.
While vector images are often smaller than pixel images, it's easy to think of examples when this isn't the case. Say I create an insanely complex vector image, complete with transparency effects, a patter made of tons of tiny shapes, etc. And lets say the image only needs to be an inch square. In this case, the vector image could be huge, and the pixel/bitmap image tiny. I know designers who make really complex vector images that are insanely big, when a comparable 300ppi TIF is 1/20th as large.
And working in InDesign, a page with perhaps several layers of Bitmap images, each cropped by vector shapes, on an INDD page with vector elements elements too, the resulting PDF (which includes vector data) is typically much larger than if you output a TIF or JPG, even if all have similar compression amounts.
Also, PDFs from Photoshop are NOT all bitmap. To see for yourself, add a layer of text and save from Photoshop as a PDF (w/o PSD compatability, and w/o flattening). Open it in Illustrator and you'll see clean vector font information.