I have a nice high resolution PNG. (Download from Dropbox) When I paste this into a new Word document, it looks good. I can't zoom in more than 500% but at that zoom level all lines are smooth, as expected.
Now I click File > Save as and select PDF from the Dropdown. From Tool > Compress Images (right next to the save button) I select "use document resolution". Then, I hit save.
Expected: The image in the PDF (viewed in Adobe Reader) should have a similar quality as the PNG.
Reality: The Image is much worse than the PNG. Maybe downsampled to 96ppi.
- When I am in the save dialog and I go again to Tools > Compress Images, the selected option is reverted to "E-Mail (96 dpi)"
- I tried the same thing on a diffewrent computer with Word 2013, but no luck.
- I tried a different PDF viewer - same image quality
- I tried to encode normal 96 ppi within the PNG and resize the image in word.
- The option "do not compress images in file" is enabled. (This option)
- This is obviously a reduced problem, so don't suggest GIMP. My real file has some text in it. Until now I am just reluctant of redoing it all in LaTeX.
- The problem gets worse, when the image is further reduced within word. This points to a resampling going on when the pdf is created.
Additional thing I have tried:
- When I use "Printing (220ppi)" instead of "document resolution" there is no discernible difference. (After all I thought that "document resolution" means that no resampling takes place and the full resolution is used.)
- Exporting to XPS format has the same characteristics.
Question: How can I preserve the image quality when exporting to PDF?