TIFF to PDF

Does TIFF to PDF keep every page of a multi-page TIFF?

Yes. PixVibe TIFF to PDF keeps up to 100 pages per file on a computer, or 30 on a phone. Each page turns into its own card and its own page of the PDF. Some scanners also store a small preview image inside the file; that preview is skipped, so it does not turn up as an extra page. A page that can't be decoded is marked “Can’t read” and left out, while the rest go through.

In a separate test on a computer, a 120-page fine-mode fax (Group 4, 204 × 196 dpi, “Original” quality) showed the note “has 120 pages; only the first 100 were added”, and building those 100 pages into a 12.7 MB PDF took about 70 seconds in Chrome on a Mac mini. Pages past the limit are not added, so split a longer TIFF into parts first.

If you want pictures rather than a document, TIFF to JPG saves one JPG per page instead.

Why is my TIFF to PDF page the wrong size?

A TIFF can record how many pixels make up an inch. With “Same as image”, PixVibe uses that number when it is 50 dpi or more, so a 300 dpi Letter scan of 2550 × 3300 pixels becomes an 8.5 × 11 inch page.

When the file has no resolution, or a placeholder value below 50, the page is sized at 96 dpi instead. The same scan then becomes a 26.56 × 34.38 inch page. Choose “Letter” or “A4” under Page size and the image is scaled down to fit the sheet; the pixels themselves are kept.

Standard-mode faxes store half as many lines per inch as fine-mode ones (98 instead of 196), so they would look squashed. We stretch them to full height, and they come out the same shape as a fine-mode fax (204 × 196 dpi).

Why is the PDF bigger than my TIFF, and when does “Smaller file” help?

A black-and-white scan or fax TIFF usually grows, while color and photo TIFFs come out smaller. PixVibe TIFF to PDF doesn't carry Group 3 or Group 4 compression into the PDF; with “Original” quality it stores each page as a lossless color image instead. Our six-page fax went from 271 KB to a 653 KB PDF, while the color scan went from 844 KB to 321 KB and the grayscale scan from 695 KB to 368 KB.

Group 4 packs pure black and white extremely tightly, which is why a fax is hard to beat. The Library of Congress description of Group 4 TIFF notes it “has also been widely used for scanning business documents”.

“Smaller file” turns every page into a JPEG at quality 75, with the longer side capped at 2,480 pixels. That suits photos: our uncompressed photo TIFF became a 5.44 MB PDF with “Original” and 218 KB with “Smaller file”. For text scans it backfires: the same fax grew to 3.03 MB, and even the mostly white color scan came out at 501 KB, larger than with “Original”. Keep “Original” for documents; in our tests it gave the smaller PDF for every text page, and the lettering stays sharp, which a JPG can't promise.

If you do use “Smaller file”, also choose “Letter” or “A4”. With “Same as image”, a 300 dpi Letter scan scaled down this way comes out at 6.39 × 8.27 inches.