Cannot open the exported png files.

[mcorovei]

I am using MacOS and I get this message: The file "3320.png" could not be opened. It may be damaged or use a file format that Preview doesn't recognize. when I run the application in the terminal.

[puntubabu]

I am also experiencing this issue. I need the tiles to be available offline on desktop, so I am generating the PNG's. All of the generated PNG's are damaged and unable to be opened. I am using macOS 10.16.2.

[nicooprat]

Same issue. Mac 10.12.6. Python 2.7.10.

[nicooprat]

Chrome seems to be able to open them, but Mac Preview, Firefox, Safari and so on can't. Same problem with JPGs.

[nicooprat]

Same issue with https://github.com/calvinmetcalf/mbliberator. For info I'm trying to unpack these mbtiles files: https://github.com/lukasmartinelli/naturalearthtiles/releases/tag/v1.0.

[sgillies]

@nicooprat @puntubabu @mcorovei If Preview can't open them, it's possible (maybe even likely) that the images in the mbtiles file are not PNG or JPEG but WebP. Reminder: the imagery is already encoded in some format in the mbtiles file and the mbutil program only reads those out as they are encoded, it does not reformat them. Can you check the documentation of your mbtiles sources and report back here?

[nicooprat]

Looks like you're right! I'll try to convert them back to jpg or png...

[nicooprat]

To convert to png, the official webp command can do it: https://www.npmjs.com/package/dwebp-bin.

To convert them to jpg: find ./ -name "*.webp" -exec ffmpeg -i {} {}.jpg \; (need to install ffmpeg first). Had to batch rename files then: find . -exec rename 's|.webp.jpg|.jpg|' {} + (rename is a Mac specific command). Finally remove old webp files with: find ./ -name "*.webp" -exec rm {} \;.

[sgillies]

I'll give @mcorovei a few days to reply to find out if this is the same issue before closing this.

[sgillies]

This seems to be resolved. We can reopen if needed.