Canon camera
Make: Canon; Model: Canon EOS R5; LensModel: RF24-70mm F2.8 L IS USMCamera and exposure fields commonly written into EXIF. GPS appears only when the camera or companion workflow records it.
Image file reference
Understand what happens inside an image file
Formats store pixels and metadata differently. This guide explains what Photo Payload can read or change, what may be lost, and how to interpret the result without overclaiming.
Practical technical guidance
Format support, local processing, image operations, metadata examples, and common questions in one maintained reference.
Supported formats and browser support
“Yes*” means parsing or processing also depends on APIs available in the current browser. “Output*” means the button is enabled only after Photo Payload verifies that the browser returns the requested MIME type.
| Format | Inspect | Clean | Compress | Resize | Convert |
|---|---|---|---|---|---|
| JPEG | Yes | Yes | Same format | Output | Output |
| PNG | Yes | Yes | Same format | Output | Output |
| WebP | Yes | Yes | Same format | Output | Output |
| AVIF | Yes* | No | Same format* | Output* | Output* |
| GIF | Yes | No | No | Input; first frame | No |
| TIFF | Yes | No | No | No | No |
| HEIC / HEIF | Yes* | No | No | No | No |
| JPEG XL | Yes* | No | No | No | No |
Animated GIF, WebP, AVIF, or PNG inputs are flattened to the first decoded frame when a tool uses Canvas. Same-format metadata cleanup does not decode or re-encode the image payload and therefore preserves animation in supported WebP and PNG containers.
How local processing works
Selecting a file gives this browser tab temporary access to its bytes. Photo Payload does not send those bytes to an application API.
- 1. Validate. The first bytes are checked against known image signatures, then file-size and decoded-dimension limits are enforced.
- 2. Process. Metadata parsing, container cleanup, or Canvas work runs in browser memory. Workers are used for expensive pixel operations when supported.
- 3. Preview. Temporary object URLs let the page display local source and output files without publishing them.
- 4. Download. The browser saves a new file. The original file remains unchanged.
Important boundary: local image processing does not mean the web page makes no network requests. Fonts, future advertising, consent tools, or analytics may contact their providers. Those systems must never receive the selected image bytes unless the product explicitly changes and discloses that behavior.
What each operation changes
Compression
Decodes and re-encodes pixels in the same format. Dimensions stay fixed, but bytes and lossy pixel detail may change. Canvas output removes embedded metadata.
Resizing
Resamples pixels to new dimensions. Fit avoids cropping, fill crops around the center, and exact can stretch an unlocked ratio. Metadata is not preserved.
Format conversion
Decodes pixels and encodes another format at the same dimensions. JPEG replaces transparency with a chosen color. Browser encoder support determines available outputs.
Metadata cleanup
Removes metadata containers from supported JPEG, PNG, and WebP files without re-encoding their image payload. Removing ICC profiles can still affect color appearance.
Metadata examples you may encounter
These are representative embedded fields from real camera and generation workflows, not promises that every file from a named source includes them. Export, editing, messaging, and screenshot workflows can change or remove metadata.
Nikon camera
Make: NIKON CORPORATION; Model: NIKON Z 8; ExposureTime: 1/250; FNumber: 2.8Standard EXIF can be readable across tools; proprietary maker-note values may require vendor-specific interpretation.
Sony camera
Make: SONY; Model: ILCE-7M4; ExposureProgram: Manual; ExposureBiasValue: 0Editing or export software may rewrite or remove the original camera fields.
OpenAI image workflow
claim_generator: OpenAI Media Service API; signed_by: OpenAI Media Service; digitalSourceType: trainedAlgorithmicMediaA signed provenance manifest can name an OpenAI service and declare trained-algorithmic media. Availability depends on the export path.
Google image workflow
claim_generator: C2PA Core Generator Library; signed_by: Google Media Processing Services; reported_as: Google LLCCredentials can name Google generation or media-processing services. SynthID itself is not ordinary EXIF and is not detected by reading visible metadata.
Stable Diffusion workflow
Software: stable-diffusion-webui; Parameters: prompt, negative prompt, steps, sampler, seedSome interfaces write generation settings into PNG text or EXIF; others export a file with no readable generation fields.
Metadata is evidence about what a file declares. It is not visual AI detection, and absence of a declaration is not proof of human authorship.
Frequently asked questions
Screenshots, downloaded social images, editing exports, and cleaned files often have no EXIF block. Photo Payload still reports file, dimensions, format, container fields, and any other readable metadata families.
A browser may decode AVIF without providing an AVIF Canvas encoder. Photo Payload checks the encoder and disables output formats the current browser cannot create.
The browser re-encodes the decoded pixels. A source that was already efficiently compressed, or a high quality setting, can produce more bytes than the original.
Metadata can be omitted by the generator, removed during download or editing, or stored in a signal this browser tool cannot read. Missing metadata is not proof that an image was made without AI.
Canvas conversion receives decoded pixels, not the original EXIF, XMP, IPTC, ICC, or C2PA containers. Reattaching cross-format metadata safely requires separate writers and verification.
No. Signed credentials describe a particular asset and its actions. Changing pixels or copying a manifest can invalidate that relationship; a new valid credential must be signed by an authorized workflow.
This reference is maintained as product behavior changes; it avoids creating separate near-duplicate pages for each format or keyword variation.