01
Dimensions, ratio and megapixels
A 6000 × 4000 image contains 24 million pixels, or 24 MP, and has a 3:2 aspect ratio. Two images with the same dimensions can have very different byte sizes due to format, compression and metadata.
Key points
- Dimensions: width × height
- Megapixels: width × height ÷ 1,000,000
- Aspect ratio: simplified width:height
- File size: encoded bytes
02
Why parsers read headers first
Header-level checks can reject implausibly large dimensions before decoding pixels. This protects memory and keeps malformed files away from expensive browser image decoders.
What this does not prove
A metadata result describes the fields and structures that the supported parser could read. It does not, by itself, prove authenticity, intent, authorship or the truth of the visible scene.