What this solves

Privacy masking and on-screen display (OSD) are the two overlay functions that most often come back as callbacks: a neighbour's window is visible again after a firmware update, or the channel title has drifted off-centre after a preset tour. Both are configured in the same area of the Dahua web interface, and both are frequently set up once and never verified against the streams the client actually watches.

This article walks through the overlay workflow documented in the Dahua Network Camera Web 5.0 Operation Manual V1.3.1, pages 40–41, and explains how to configure masks and titles so they survive presets, reboots and day-to-day operation. It also covers what to check when they do not, and how to specify cameras for sites where masking is a contractual requirement rather than a convenience.

How the workflow works

In Web 5.0, overlay settings live under Camera > Encode > Overlay. That single page hosts privacy masking, channel title and the other overlay items described in section 6.2.2.2 of the manual. Because the settings sit on the encode path, they are burned into the video the camera produces — the recorder, the client software and any ONVIF consumer receive the masked image, not a clean one with a flag attached.

Privacy masking (section 6.2.2.2.1, page 40) offers two mask types. Color Block lets you draw triangles and convex quadrilaterals, supports up to 8 blocks, and the colour is black. Mosaic lets you draw rectangles as blocks. The exact set of shapes and the maximum block count for mosaic mode are cut off in the supplied extract, so treat the mosaic limits as model/firmware dependent and confirm on the bench.

Channel title (section 6.2.2.2.2, page 41) is simpler: enable it, type the title, choose the text alignment, and apply. The title is then displayed on the Live page and in the encoded stream. Neither function depends on PTZ position, which is precisely why they hold through preset recalls — the mask is anchored to image coordinates, not to where the dome is pointing.

Prerequisites and site checks

Before touching the overlay page, confirm you can reach the camera's web interface with sufficient privileges. The manual documents the configuration steps but not the user-role matrix, so whether an operator-level account can edit masks depends on model/firmware — plan on an administrator session for commissioning.

Second, decide which streams matter. A camera typically exposes a main stream and one or more sub streams, and the overlay page is where you confirm what is applied where. If the recorder records main stream but the client wall shows sub stream, both must be checked visually, not just the one you configured on.

Third, walk the scene. Masks are drawn against a live image, so any change in field of view — a lens swap, a bracket adjustment, a re-aimed varifocal — invalidates the coordinates. Photograph the intended coverage area and note the objects that must be hidden: windows, doorways, neighbouring property, staff break areas, payment terminals.

Finally, check the firmware version and record it in the handover pack. Overlay behaviour and available mask types can change between releases, and a version number turns a vague "the mask moved" complaint into a reproducible test.

Step-by-step configuration

The sequence below follows the manual's procedure on pages 40–41. Menu labels are as printed; anything not confirmed in the packet is flagged.

Step 1 — Open the overlay page. Navigate to Camera > Encode > Overlay. This is the parent page for both privacy masking and channel title.

Step 2 — Enable privacy masking. Open the privacy masking section (6.2.2.2.1). Click next to Enable to turn the function on. Choose the mask type — Color Block or Mosaic — before drawing, because the available shapes differ between the two.

Step 3 — Add and place a block. Click Add, then drag the block to the area you need to cover. Adjust the size of the rectangle to protect the privacy. For Color Block mode, the manual notes you can draw triangles and convex quadrilaterals and drag up to 8 blocks, all black.

Step 4 — Apply. Click Apply to commit the mask. Do not skip this — the block is only a draft until applied, and navigating away without applying discards it.

Step 5 — Refine existing blocks. Select a rule in the list; it highlights and the block frame appears in the image. You can then move the position and adjust the size. Double-click the name in the Name column to rename a block — useful when a scene has several masks and the handover pack needs to reference them. Use Clear (or the delete control) to remove blocks you no longer need.

Step 6 — Configure the channel title. Go to Camera > Encode > Overlay > Channel Title (section 6.2.2.2.2, page 41). Click next to Enable, enter the channel title, select the text alignment, and click Apply.

Step 7 — Verify on Live. The manual states overlay information is displayed on the Live page. Check the Live view for each stream you intend to expose, and confirm the mask covers the target and the title sits where the alignment setting implies.

Tuning and verification

Configuration is the easy half. Verification is where most installations fail, because the person who drew the mask is rarely the person who reviews the recording three weeks later. Build a short test script and run it on every camera where masking is a requirement.

Start with a reboot. Power-cycle the camera or reboot from the web interface, wait for it to come back, and re-check the Live page. Masks and titles should return exactly as applied; if they do not, the most likely causes are an unsaved draft, a profile change, or a firmware behaviour difference. Next, exercise the PTZ presets if the camera has them — recall each preset and confirm the mask still covers the intended area. Because the mask is drawn in image coordinates, it should track the scene, but a preset that changes zoom or focus can shift the framing enough to expose an edge.

Then check every stream and every consumer. View the main stream in the web Live page, pull the same stream into the recorder, and check the sub stream on a mobile client if one is in use. If the site uses ONVIF integration, confirm the third-party platform shows the masked image — the overlay is burned in, so it should, but a quick check closes the argument later.

Finally, record the result. A screenshot of the overlay page, a screenshot of the Live view, the firmware version and the date form a handover record that answers most future queries without a site visit.

A note on tuning the mask itself: draw slightly larger than the object you are hiding. A block that exactly frames a window will expose a sliver the moment the camera is nudged or the scene is re-framed by a preset. The manual allows you to select a rule and adjust size at any time, so err on the generous side and trim later if the client objects to over-coverage.

Buying notes and deployment fit

Privacy masking is a camera-side function, so the specification question is not "does the recorder support it" but "does the camera, at the firmware you will ship, support the mask types the site needs". Confirm Color Block and Mosaic support, the maximum block count, and whether the model allows the shapes you intend to use. The manual documents up to 8 blocks for Color Block; mosaic limits are not confirmed in the supplied extract and should be verified per model.

For sites where masking is contractual — schools, clinics, retail back-of-house, residential boundaries — specify cameras with a mature web interface and a documented overlay page, and budget commissioning time for the verification script above. Our network cameras collection lists the models we stock; if you are pairing cameras with a recorder, check the network recorders range for channel counts and stream handling that match the deployment.

Where analytics and overlay density matter — face statistics, target boxes, AI rules — the higher-tier platforms are worth the step up. The WizMind range is the place to start that comparison. Note that AI-related overlays such as face statistics are configured through their own pages (the manual cross-references section 6.2.2.2.12 from the face recognition parameters table on page 142), so plan the OSD layout as a whole rather than mask-by-mask.

For integration projects, confirm ONVIF conformance with the ONVIF specification and test the masked stream in the target VMS. Manufacturer documentation is at Dahua Security; always download the manual for the exact firmware you are deploying rather than relying on a generic guide.

FAQ

Do privacy masks survive a reboot? Yes, once applied. The mask is a saved configuration item under Camera > Encode > Overlay, so it returns after a power cycle. The common failure is a mask that was drawn but never applied — click Apply and re-test after a reboot.

Do masks move when a PTZ preset is recalled? The mask is drawn in image coordinates, so it stays anchored to the framed scene rather than to the dome position. If a preset changes zoom or framing significantly, the mask can end up covering the wrong area — re-check each preset after commissioning.

How many blocks can I draw? For Color Block, the manual states you can drag up to 8 blocks, and the colour is black. Limits for Mosaic mode are not confirmed in the supplied extract and depend on model/firmware.

Can I use triangles as well as rectangles? Yes in Color Block mode, which supports triangles and convex quadrilaterals. Mosaic mode uses rectangles. Switch the mask type before drawing if you need non-rectangular shapes.

Where do I set the camera name shown on screen? Under Camera > Encode > Overlay > Channel Title. Enable the function, enter the title, choose the text alignment, and click Apply. The overlay is displayed on the Live page.

Will a third-party VMS show the mask? Because the overlay is part of the encoded image, an ONVIF-compliant consumer should receive the masked stream. Test it in the actual VMS before handover, and confirm the stream you are testing is the one the client will watch.

Sources

Dahua Network Camera Web 5.0 Operation Manual V1.3.1 — page 40 (section 6.2.2.2 Overlay; 6.2.2.2.1 Configuring Privacy Masking; encode parameters including I Frame Interval, Virtual I Frame, SVC, Watermark), page 41 (Figure 6-18 Privacy masking; related operations for viewing, editing, renaming and deleting blocks; section 6.2.2.2.2 Configuring Channel Title; Figure 6-19 Channel title), page 142 (face recognition parameters table, including OSD Info cross-reference to section 6.2.2.2.12 Configuring Face Statistics).

Official links: https://www.dahuasecurity.com/ and https://www.onvif.org/.