"Best way to save image metadata to PNG with Python?"
Hey folks!
I’ve been messing around with images in Python and need to save some extra info (like author, timestamp, etc.) into a PNG file. I know JPEG has EXIF, but PNG’s a bit different, right?
What’s the easiest method to *python save image metadata png* without losing quality?
I tried PIL/Pillow but couldn’t figure out how to *properly* store custom fields.
Any libs or snippets you’d recommend?
Bonus points if it’s lightweight and doesn’t require 10 dependencies lol.
Thanks in advance!
(Also, if you’ve got horror stories about metadata corruption, I’d love to hear ‘em—might save me some pain.)
Hey! Pillow actually *can* handle PNG metadata, but it's a bit hidden. You wanna use `info` dict when saving:
```python
from PIL import Image
img = Image.open("your.png")
img.save("output.png", pnginfo={"Author": "You", "Timestamp": "2024-01-01"})
```
Not all viewers will show it, though. For a deeper dive, check out `PyPNG`—it’s lightweight and gives more control.
And yeah, I’ve had metadata vanish after resizing... *sigh*. Always keep backups!
If you're looking for a *simple* way to python save image metadata png, try `piexif`! It’s mostly for JPEG but has some PNG support.
Otherwise, `pypng` is your friend—super minimal dependency.
Pro tip: Test with a copy of your file first. Once metadata’s gone, it’s *gone*.
PNG uses chunks (like tEXt, zTXt) for metadata, not EXIF. Pillow’s kinda clunky here.
For *full* control, `pngchunk` lib lets you edit chunks directly. Bit more coding, but way more flexible.
Also, avoid spaces in keys—some tools hate that.
lol i feel your pain. spent *hours* on this last week.
Pillow works but is picky. Try this:
```python
meta = {"Description": "My cool image"}
img.save("out.png", pnginfo=Image.PngInfo().add_text(*meta.items()))
```
Weird, right? But it sticks.
OP here—wow, thanks for all the tips!
Tried the `Pillow` + `PngInfo` trick and it *worked* (after 3 fails lol).
Quick Q: Anyone know if `tEXt` vs `zTXt` matters for compatibility? Some tools show one but not the other.
Also, sidecar JSON is smart... might do that for critical stuff.
Y’all saved me hours of rage-quitting. Cheers! 🍻
Honestly, if you’re *just* storing basic text, `tEXt` chunks are the way.
`Pillow` can do it, but `imageio` + `meta` param is cleaner IMO.
```python
import imageio
imageio.imwrite("file.png", data, meta={"author": "me"})
```
Less headache, same result.
For *lightweight* python save image metadata png, skip the big libs.
`png` module (yes, that’s its name) is tiny and lets you inject raw chunks.
Example:
```python
import png
writer = png.Writer(...)
writer.chunks.append(("tEXt", "Author\x00Me"))
```
Weird syntax, but it *works*.
If you’re *paranoid* about corruption (like me), store metadata *outside* the image.
Use a sidecar `.json` file. Yeah, it’s extra work, but zero risk of losing it during edits.
Otherwise, `Pillow` + `PngInfo` is *fine*, just... test thoroughly.
Pro tip: Some tools *strip* metadata on save (looking at you, GIMP).
If you python save image metadata png, always verify with `exiftool` afterward:
```bash
exiftool -g1 -a -s your.png
```
It’s not Python, but it’s *gold* for debugging.
