Inventory by role
Record URL, page, subject, informative or decorative role, any link, language and visibility.
GUIDE / PROTOCOL
Audit a site’s editorial images
A useful image explains something; its role, source and representation should be explicit.
Direct answer
How do you decide which images to keep or fix?
Inventory images by page and purpose. Distinguish informative, decorative and functional images; check provenance and rights, accurate representation, text alternative, caption, dimensions and presence in HTML.
01 / Review method
Review method
Verify provenance
Record creator, origin, licence or permission, date, edits and any generation disclosure. Remove uses with unestablished rights.
Test meaning and access
Write contextual alternatives for informative images; avoid unnecessary announcements for decoration. Review captions, nearby text and contrast.
Check delivery
Inspect src and srcset, format, dimensions, loading priority where appropriate, file size, mobile display and licence metadata when relevant.
IN PRACTICE
An image needs a role, a source and a useful format
Decide what the reader must understand first. An atmosphere image may introduce a topic; an image used as evidence needs an origin and context. Decide cropping, caption and file weight afterwards.
Which check comes first?
Choose the situation you observed. Each path gives a first check, useful evidence and the limit of that check.
A photograph has no identifiable source
- First check
- Find the first traceable record and compare image, caption, date and credit. Separate the image producer from accounts republishing it.
- Evidence to retain
- Exact URL, document identifier, credit, known capture and publication dates, and the passage establishing context.
- Limit to remember
- Recognising an image does not confirm an event claimed by a new caption. An unsuccessful search does not prove fabrication.
Cropping removes necessary information
- First check
- Compare the full image with the crop actually shown on mobile and desktop. Check faces, captions, scales, landmarks and details needed for understanding.
- Evidence to retain
- Original image, crop, displayed dimensions, positioning rule and an example of the lost detail.
- Limit to remember
- An attractive crop can change meaning. Alternative text helps according to the image’s role but cannot alone make an unreadable chart usable.
An image seems to delay rendering
- First check
- Identify the file actually loaded, its size and discovery in the network timeline. Compare its width with the display and check whether it carries the main content.
- Evidence to retain
- Image URL, received variant, dimensions, transferred bytes, device, network and repeated measurements before and after the fix.
- Limit to remember
- Smaller files do not resolve late discovery. An undersized variant can harm readability; do not choose compression by byte count alone.
Further reading
| Situation | Avoid | Useful correction |
|---|---|---|
| Atmosphere image | Presenting a generated scene as a real event. | State its illustrative role and AI generation. |
| Documentary photograph | Reusing an attractive image without date or provenance. | Link the record, author or institution, capture date and reuse terms. |
| Explanatory chart | Keeping numbers only inside pixels. | Also provide values, units and limits as readable text or a table. |
Role
What meaning disappears if the image is removed?
Provenance
Which source and caption justify its use?
Format
Which variant stays sharp at the actual display size?
Final check
Review with images hidden, then on a small screen. The caption must remain understandable and essential meaning must not depend on colour alone.
Image weight
Site WebP files; an estimated scenario, not a traffic or speed measurement. Cache, screen density and other resources affect actual results.
Estimated total : 100.5 KiB
960 px reference : 283.1 KiB
Weight difference : 182.6 KiB
| File width | Estimated total |
|---|---|
| 480 px | 100.5 KiB |
| 768 px | 203.6 KiB |
| 960 px | 283.1 KiB |
- Editing desk with photo prints in different formats, a loupe and ruler. Illustrative scene.
- Measurement desk with cards, magnifier, stopwatch and prism. Illustrative scene.
- Earth photographed by the Apollo 17 crew on 7 December 1972. NASA, AS17-148-22727.
Documentary references
Consulted on .
An authentic photo can be used outside its time context
Apollo 17’s Earth photo offers a concrete case: identifying a photograph does not date the story attached to it. The date of a page republishing it and the capture date are separate facts.
- Capture date
- Document identifier
- AS17-148-22727
Check before citing
- Find AS17-148-22727 in the record, then compare the image and caption.
- Keep capture, publication and consultation dates separate. Recent republication does not make a photo recent.
- For a Worldview layer, also record sensor, date and processing: this historical photograph is not a Worldview screenshot.
Real documentary case, consulted on 2026-10-14. Resized and encoded WebP version, with no crop or AI retouching.
A page date is not its photograph’s date
Earthrise lets us compare three documented dates. The photograph is real; the two official records give its context.
- Capture date
- NASA Science record published
- Republication article
Republication in 2024 does not make this a photograph taken in 2024. Retain the capture date and the reference for each consulted page.
What does a consultation date establish?
It dates your access to a source. It replaces neither capture nor publication and does not prove the page was identical earlier.
Sources consulted on . WebP version resized from the NASA-supplied file, without cropping or AI retouching.
02 / Evidence to keep
Evidence to keep
Image register
Page, file, role, editorial owner and review date.
Rights trail
Source, licence or permission, restrictions and known transformations.
Meaning check
Alternative, caption, context and reason for decorative or informative treatment.
Technical check
Served HTML, dimensions, formats, weight and mobile result.
PRACTICAL CHECK
Before reaching a conclusion
A frequent misreading and the check that helps avoid it.
Premature conclusion
A sharp, well-compressed image can still mislead if miscaptioned, used as evidence when decorative or inconsistent with the language version.
Decisive check
Check editorial role, origin, rights, date, caption and alternative text in each display context. Test framing and legibility at actual delivered sizes.
AFTER THE REVIEW
Decide from the evidence
An image is relevant but permission is missing
Remove it from public delivery until rights are evidenced, then record licence, restrictions and modifications.
The image conveys information absent from text
Add a contextual alternative or nearby text; check understanding with the image hidden.
Decision and review trail
Decision and review trail
What the check must help decide and what to retain so the choice can be reviewed.
Sufficient evidence
For each priority image, inspect file, dimensions, crop, alt text, usage rights and consistency across page, social preview and markup. File presence alone is insufficient.
Next decision
Replace misleading or heavy images and retain provenance. Recheck common viewport sizes and public metadata after publication.
OSINT / Official references
When an image is considered for publication
Separate file provenance, depicted signs and reproduction rights.
Gallica · BnF
Why start hereCheck the edition and reuse conditions of a digitised document.
Limit to rememberA digital copy does not validate every statement in the document. Check provenance, OCR errors and resource-specific reuse terms; a BnF building photograph’s license does not apply to those documents.
Read source entryDATA INPI
Why start hereCheck whether a visible sign matches a French trademark filing.
Limit to rememberRead each registration or filing with its status, date and protection scope.
Read source entryEUIPO · DesignView
Why start hereReview registered designs without assuming permission to use them.
Limit to rememberA visual search does not establish complete rights coverage or freedom to operate; check status and territory.
Read source entryDetailed inspection cases
Typical situations for preparing a check. They do not describe completed assignments or actual observations.
Usage conditions are no longer documented
What to inspect
Find the original media, stated creator, associated notice and consultation date. Check that the available conditions apply to this version and intended use.
Decision and action
Replace or suspend the integration if necessary permission remains undetermined. Keep the documentary reference rather than treating online availability as authorisation.
Record to retain
Keep the original URL, consulted notice, version, date and editorial obligations applied, including attribution where specified.
A cropped variant removes essential context
What to inspect
Compare the original with mobile and desktop sizes. Check missing captions, scales, people or areas and whether alternative text matches what remains visible.
Decision and action
Adjust the crop or choose another presentation when the loss changes the information. Describe the image’s function without promising elements absent from the variant.
Record to retain
Keep variants, dimensions, breakpoints and the rationale for cropping and alternative text.
The selected variant transfers excessive bytes
What to inspect
Compare displayed width, currentSrc and transfer on mobile and desktop.
Decision and action
Adjust sizes and variants while preserving subject readability.
Record to retain
Width, selected file, bytes and framing check.
Review before deciding
These questions complement the method. They help establish what is actually supported while retaining qualifications in the record.
Origin and purpose
Are origin, known rights and modifications documented? Do caption and alternative distinguish documentary photo, logo, diagram and atmosphere illustration?
View a worked decision
Fictional example: the state applies only to the criterion and scope described.
- Fictional observation
- An image is labelled “free” in a folder; author, exact licence and original page are missing.
- Declared state
- Not checked
- Decision and next check
- Do not validate rights from this label alone. Find source and terms, or choose a documented resource.
Actually displayed file
On a small screen, does the chosen file retain dimensions, clarity and meaningful framing? Also check lazy loading and missing resources without artificially enlarging a poor original.
View a worked decision
Fictional example: the state applies only to the criterion and scope described.
- Fictional observation
- On mobile, the crop removes the embedded key distinguishing actual data from forecast.
- Declared state
- Observed discrepancy
- Decision and next check
- Fix the crop or provide a visible text key. Check the selected file, not only the original.
Data behind a chart
Does a chart have a textual account of its useful information? A generic alternative such as “chart” conveys neither values nor trend.
Documentation consulted : W3C WAI · Images Tutorial ·
View a worked decision
Fictional example: the state applies only to the criterion and scope described.
- Fictional observation
- The tested inventory has no data-bearing chart or diagram, only atmosphere photos.
- Declared state
- Justified exclusion from scope
- Decision and next check
- Justify excluding charts. Photo alternatives still require checking; reopen when a chart is added.
TOOLS / REGISTERS
Information to record
Identify the media role before writing its alternative text: evidence, illustration or decoration. Link evidence to its source; clearly label an illustrated scene without assigning it a real location.
- Access date and time zone
- Exact URL
- Media size / dimensions
- Alternative text / role
- Licence / reuse rights
- Claim to verify
- Decision / next action
- Review owner
- Next review
03 / FAQ
Frequently asked questions
Does every image need descriptive alt text?
No. Pure decoration may use empty alt; informative images need an alternative suited to context.
Is a CSS background enough for search?
For important editorial imagery, use an img element with src and nearby text; Google does not index CSS backgrounds as HTML images.
When add a caption?
When it gives source, fact, date or context that the image cannot establish alone.
What if rights are unclear?
Pause public use, find the licence evidence or replace the image with an authorized one.
04 / Official references
Official references
Describe a context
DOCUMENTED REFERENCE
Resource Timing: three sizes and several possible causes of zero
Encoded body size, decoded body size and the transfer indicator describe different objects. These rules come from the W3C Candidate Recommendation Draft of 1 September 2026, still undergoing standardization.
Encoded body → HTTP decoding → decoded body; no indication of pixel memory.
| Reference | Value or form | What it identifies |
|---|---|---|
| encodedBodySize | encoded body | encodedBodySize describes the body before content encoding is removed, such as HTTP decompression. It is neither the original unpublished file size nor every exchange for the page. |
| decodedBodySize | decoded body | decodedBodySize describes the body after HTTP content decoding. For an image, it does not give the memory occupied by decoded screen pixels. HTTP decompression and JPEG decoding are different operations. |
| transferSize | encodedBodySize + 300 | In this draft, transferSize adds a constant 300 to the encoded body outside cache cases. This avoids exposing actual header sizes: do not describe it as an exact count of network bytes. |
| CACHE | local: 0 · validated: 300 | The rule distinguishes local cache returning zero from validated cache returning 300. Validation may require a network exchange without returning the full body. Stored body size and exchange size differ. |
| VISIBILITY | TAO ≠ CORS | Visibility restrictions can also make fields zero. Timing-Allow-Origin exposes timing information; CORS governs a different access mechanism. Zero alone proves neither caching nor an empty file. |
| SERVICE WORKER | client ↔ worker | With a service worker, exposed timings may describe the client–worker path. They do not automatically reveal the worker’s internal network request. Identify intermediaries before comparing observations. |
Implication for the record
These rules describe a dated draft, not identical support in every browser. Record browser and version; check headers and cache context before drawing conclusions.
Is decodedBodySize the image’s memory footprint?
No. It concerns HTTP content decoding. Image format, dimensions and decoding into pixels belong to other stages.
Primary documentation
Documentation consulted on .
DOCUMENTED REFERENCE
CSS framing: measure what cover clips and contain leaves empty
The same thumbnail box can show different parts of an image depending on its fit. Both modes preserve aspect ratio but satisfy opposite constraints. This explorer calculates a centred geometric model from already oriented dimensions.
| Reference | Value or form | What it identifies |
|---|---|---|
| contain | min(Cw / W, Ch / H) | contain uses the smaller scale factor. The entire image fits inside the box; unused bands may remain. |
| cover | max(Cw / W, Ch / H) | cover uses the larger factor. The box is filled and the overflowing image is clipped. |
| rendered | W × s ; H × s | Rendered dimensions are the image width and height multiplied by the factor. They are not necessarily the visible box dimensions. |
| object-position | 50% 50% | With object-position: 50% 50%, excess is split equally on each axis. The calculation reports left/right and top/bottom crops in source-image units. |
| fill ≠ cover | aspect ratio | fill can change aspect ratio and differs from cover. none and scale-down have other rules and are not simulated here. |
Explore centred framing
Four integers from 1 to 20,000. Already oriented image; object-position: 50% 50%.
Centred geometric calculation; results rounded to four decimals.
- Scale · CSS px / source px
- 0.3333
- Rendered size · CSS px
- 400.0000 × 266.6667
- Left and right crop · source px per side
- 0.0000
- Top and bottom crop · source px per side
- 100.0000
- Left and right unused band · CSS px per side
- 0.0000
- Top and bottom unused band · CSS px per side
- 0.0000
Implication for the record
Image dimensions represent square source pixels in this model; the box uses CSS pixels. The diagram is an illustration, not a photograph or a measurement of a file. The calculation ignores rasterisation rounding, borders and CSS transforms. An off-centre subject can still be clipped despite correct geometry: inspect points of interest and credits across formats.
Primary documentation
Documentation consulted on .
Related checks
- A real satellite image with two dates to retain
- Digitised heritage: a rights statement is not a licence
- EXIF: assemble a timestamp from the right components
- C2PA: validate provenance without certifying the scene
- Read Core Web Vitals thresholds without inventing a verdict
- Text contrast: compare the ratio before rounding
- Exif orientation: eight arrangements, not just four rotations
DEEPER READING / PRACTICE
Check the role and consistency of the images
A image illustrates a topic but may suggest a place, a person or an event that the page does not document. The audit examines editorial function, context and related information.
Updated on .
Priority checks
Release source, legend, alternative text, dimensions and variants. Check that the image corresponds to its role: illustration, document, portrait or purely decorative element.
Interpretation pitfalls
A visually relevant image is not a proof of the statement. A too precise legend or alternative text may enter an attribution that the file does not allow to set up.
Working record to retain
The image inventory combines page, file, role, origin and control to be performed. The corrections may concern the context, the legend, the weight or the choice of the illustration itself.
PRACTICAL CASE / WORKED EXAMPLE
An illustration looks like a field document.
The example is a web control educational situation. It connects the defect to a concrete path and describes a way to verify the correction, rather than consider the only publication of the change as a proof of resolution.
Example context
An image accompanies a search text and can be understood as a photograph of the case described. The page does not specify its role or origin.
Suggested approach
Examine legend, context and alternative text. Difference between illustration and documentary. Adjust the presentation or choose another visual if the ambiguity persists despite an explanation.
Conclusion and next step
The role of the image becomes explicit. The evidence remains separated from the visuals intended to help the understanding or to install an editorial context.
Questions for deeper practice
Can the alternative text replace a legend of origin?
It describes the information useful to the understanding of the image. The source and editorial role may require a distinct visible mention, especially when the attribution affects the reading of the document.
DETAILED WORKSHOP / APPLICATION
See what the visual makes you understand.
01 / Prepare the necessary information
Assemble image, legend, alternative text and page context. Define the expected role: document, illustration, portrait or decorative element.
02 / Carry out the approach
Read the page with and without the visual. Identify the places, people or events that the image may suggest. Check the source, attribution and context elements necessary for this reading.
03 / Examine an alternative situation
If the image is illustrative but looks documentary, adapt the presentation or the visual. A legend must illuminate its role without giving it evidence that it does not provide.
04 / Decide on the next step
The use is consistent when the reader can understand the visual function. Weight and size controls complete this reading without replacing the editorial control.
05 / Hand over the verification records
Transfer files, uses and decisions. The pages that reuse the image are reviewed if a correction concerns its origin, legend or interpretation.
ANNOTATED WORKING DOCUMENT / REVIEW GRID
Editorial use of the visual
The file preserves file, origin, role, legend and alternative text. It examines what the image makes understand and separates document of proof, illustration and decoration.
On a small screen, scroll the grid horizontally to read all three columns.
| Observation | Supported interpretation | Next step |
|---|---|---|
| The illustrative role is clear on the page. | The visual supports understanding without being presented as a documentary. | Check the variants and information associated with its other uses. |
| The legend attributes an undocumented place. | The presentation adds a statement that the file does not allow to set up. | Re-view the legend or choose an image adapted to the context. |
| The recharge removes an element that changes the meaning. | The version may suggest a different reading from the original. | Compare the uses and restore the necessary context. |
Reviewing the working document
The final verification compares what the text affirms and what the visual suggests. The dimensions and weight are useful for technical control, but do not demonstrate the documentary relevance of the image.
REPORTING / EXAMPLE WORDING
Presentation of results: Check the role and consistency of the images
Point to clarify
The role of a visual must be understood without giving it any additional evidence.
Before handing over
Join the text, image and information that accompanies its use.
Example of a qualified conclusion
The image fills the role indicated in the page context. The legend and the alternative text do not add any attribution that exceeds its documented origin.