PDF Thumbnails Not Showing.

[davidcc 0]

Good Morning.

I have recently upgraded to Evernote Personal and have been happy with it so far. However, I uploaded a couple of PDF files and found that there was no thumbnail preview shown on the notes list or the home screen. Do I need to enable anything? or is this an Evernote glitch?

[PinkElephant 8,114]

Usually it shows. But first thumbnailing is done on the server, it can take a while. And second there are pdfs that contain no picture information - the picture layer can be empty. AFAIK thumbnails are made from the picture layers content.

[davidcc 0]

Many thanks for your reply. So if my PDF has no pictures, then a thumbnail wouldn't show up.

[PinkElephant 8,114]

As I understand it: No.

Because EN takes the thumbnail from the content of the picture layer. Thumbnailing is looking for a picture, and reduces its size by cutting down the dimensions. It has maybe 1.600 x 1.200 pixels in the original - the thumbnail maybe has only 32 x32 pixels (don’t know exactly). This reduces the size of the picture by 99%, which makes it easy to show in a list mode. The thumbnail is a separate new picture file, saved in the notes metadata.

You see this sometimes when a pdf contains a logo - this logo shows as thumbnail, and nothing else. In this case all the other information is in a text layer, the logo is the only picture layer element.

PDFs are organized in layers. It can be a valid pdf with nothing (= white) in the picture layer, and all information in a text layer. The thumbnail will look plain white as well. Using a pdf editor you can check if this is true. What the thumbnail creation does not do is look at the page like we do it, and take a snapshot of all content, including the text layer.

[Mike P 2,642]

You might reasonably think that adding a suitable picture to the note would replace the blank pdf thumbnail. However, as noted elsewhere, EN will never replace the thumbnail once it is created. If you desperately need a better thumbnail you would have to create a new note, add a picture (e.g. a screen shot of the first page of the pdf) and only then add the pdf. Another reason why we should have more control over the note thumbnail.

[PinkElephant 8,114]

… add a picture, save the note, let it sync and wait until a thumbnail shows. Only then add the pdf to the note …