I have several pages imported from scanner in PNG format. I use image editor to clean some noise, downscale to 100PDI, convert image palette to grayscale, etc. Finally I've got a bunch of PNG images of small size, looking good at computer screen still.
Then I need to save these PNG pages to a single PDF file for distribution. Earlier I was able to achieve this using Preview.app. However in macOS X High Sierra 10.13 this approach does not work any longer because Preview.app is trying to downscale PNG images by 30% to fit page size. After this transform the image is not sharp enough any longer.
In earlier versions of macOS X Preview.app generated PDF file without transforming the images.
Is there a way to make a PDF file from a set of PNG images using these images as-is (without any transformation)?
Best Answer
ImageMagic
You can use ImageMagick to convert your PNG images to PDFs.
See How can I convert a PNG to a PDF in high quality so it's not blurry or fuzzy? for a related question and answers over on the Unix & Linux site.
Installing ImageMagick and
convert
To install the free and open source ImageMagick, and the included
convert
tool, you can use the Homebrew project.Once
brew
is installed, use the following command to install ImageMagick:Online Services
Alternatively, you can use a web service to perform the conversion for you. Search for convert png to pdf to find such services: