Meow
AI
image metadata format
SHOW HN2025
98points
78comments
#746of 3,837 in 2025
Top 20%of 2025 by points
How HN took it
RoastedHalf or more of the comments are critical
3 positive, 11 neutral or asking, 1 mixed, 36 critical, out of 51 comments about the project. Thread score -0.60.
Idea: 3 for, 21 againstExecution: 0 for, 4 againstDesign: 0 for, 4 againstPrivacy: 0 for, 3 againstDocs: 0 for, 2 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Embedding data alongside the image is a useful idea for pipelines
From 2 comments
Cool idea. I can see it being useful in a pipeline, where you mutate the image as you go. Losing referenced data can be a pain. Are you able to extract the original image?
jpollock on HNGreat idea and insight. If i understand, it will allow you to embed metadata such as bounding box coordinates and class names, something I have also been working on[0] --…
voxleone on HN
Objections
Steganographic metadata is fragile and lost on resizing, recompression or JPEG conversion
From 4 comments
So converting the file to a lossy format, or resizing the image as png will destroy the encoded information? I see why one wants to use it, but I think it can be only useful in a…
ahofmann on HNMetadata gets stripped by most websites. Embedding metadata into the pixels by using the least significant bits of RGB won't cut it, that stuff is gone when the file becomes a…
Dwedit on HNDoes this survive resizing images or converting from png to jpg? (or worse, taking jpg screenshots of resized pngs). Because that also happens a lot when sharing images.
hiccuphippo on HN> Instead of storing metadata alongside the image where it can be lost, MEOW ENCODES it directly inside the image pixels using LSB steganography That makes the data much more…
fao_ on HN
Existing formats and EXIF/sidecar JSON already solve this
From 4 comments
Reality check: Your extra data is a big JSON blob. Okay, fine. File formats dating back to Targa (https://en.wikipedia.org/wiki/Truevision_TGA) support arbitrary text blobs if…
ai_critic on HNMaybe I'm jaded, but I fail to see how a bespoke file format is a better solution than bundling a normal image and a JSON/XML document containing metadata that adheres to a…
gavinray on HNThis is not a good idea in practice. Why not bundle the metadata as JSON or Protobuf via an aux file?
kookamamie on HNWhy not simply JXL? It has multiple channels, can store any metadata, is lossy/lossless.
jbverschoor on HN
LSB embedding introduces visible noise and degrades training data
From 2 comments
Modifying the image in any way (cropping, resizing, etc) destroys the metadata. This is necessary in basically every application that interacts with any kind of model that uses…
bastawhiz on HNNice work! Though I have one question: once 2 bits/channel are used with Meow-specific data thus leaving 6bits/channel, I doubt how it can still retain perfect image quality when…
can16358p on HN
Precomputed features like edge maps become obsolete and are poorly motivated
From 2 comments
You're adding metadata, but what problems does this added metadata solve exactly? If your converter can automatically compute these image features, then AI training and inference…
a2128 on HNI don't understand the purpose of effectively hard-coding things like edge detection and attention weight maps into the image. There are various ways to do edge detection and…
kevingadd on HN
Requests
Add redundancy and error correction
From 2 comments
Hi! Thanks for checking it out, means a lot :) Yes, it is a big JSON blob atm, haha and t's definitely still a POC, but the idea is to avoid having a separate JSON file that adds…
kuberwastaken on HNThat's fair and how it's traditionally done but the entire idea of this was to have everything you need on the image itself and reduce the complexity and extra files, no risk of…
kuberwastaken on HN
Test how much re-encoding the format survives
From 1 comment
Great point, I like that idea too: I’ll definitely look into adding redundancy and testing how much re-encoding it can realistically handle without noticeable image damage.…
kuberwastaken on HN
Consider a sidecar-style naming like image.png.meow
From 2 comments
It would be better to use this as an additional extension before the normal extension like other tools that embed additional metadata do. For example, Draw.io can embed original…
zdw on HNWhy not store metadata, along with a checksum of the png, in myPublicPhoto.png.meow? Labeling and metadata a separate concerns. "Edge detection maps" etc are implementation…
moritzwarhier on HN
Questions
Does the metadata survive resizing or PNG to JPG conversion?
From 2 comments
Does this survive resizing images or converting from png to jpg? (or worse, taking jpg screenshots of resized pngs). Because that also happens a lot when sharing images.
hiccuphippo on HNSo converting the file to a lossy format, or resizing the image as png will destroy the encoded information? I see why one wants to use it, but I think it can be only useful in a…
ahofmann on HN
What happens when the metadata exceeds the pixel capacity?
From 1 comment
The amount of information you can encode using EXIF/IPTC doesn't have an upper-bound the way that using stenography is inherently capped by the resolution of the image. What…
vunderba on HN
Can the original image be extracted?
From 1 comment
Cool idea. I can see it being useful in a pipeline, where you mutate the image as you go. Losing referenced data can be a pain. Are you able to extract the original image?
jpollock on HN
Alternatives named
EXIF and iTXt metadata chunks in PNG
From 1 comment
Reality check: Your extra data is a big JSON blob. Okay, fine. File formats dating back to Targa (https://en.wikipedia.org/wiki/Truevision_TGA) support arbitrary text blobs if…
ai_critic on HN
JPEG XL, WebP, HEIF, JPEG 2000
From 2 comments
> Instead of storing metadata alongside the image where it can be lost, MEOW ENCODES it directly inside the image pixels using LSB steganography That makes the data much more…
fao_ on HNWhy not simply JXL? It has multiple channels, can store any metadata, is lossy/lossless.
jbverschoor on HN
Sidecar JSON bundled with the image
From 1 comment
Maybe I'm jaded, but I fail to see how a bespoke file format is a better solution than bundling a normal image and a JSON/XML document containing metadata that adheres to a…
gavinray on HN