Contact angle and droplet profile analysis algorithm services
For seat drop images and controlled wetting tests, algorithm evaluation and project adaptation of droplet contours, contact baselines, left and right contact angles, geometric quantities and contact line states are provided. Method selection depends on droplet morphology, baseline quality, scale, and physical assumptions.
Applicable objects and analysis tasks
It is suitable for droplet analysis tasks where the droplet boundary is visible, the contact baseline is definable, and the shooting direction and scale are clear. Corporate projects are typically used for material wettability studies, surface treatment comparisons before and after, process trend observation, or instrument software module integration.
- Extract seat drop contours, contact points and contact baselines.
- Calculate left and right contact angles, fitted geometric parameters and residuals.
- Calculate the contour volume and surface area when the axial symmetry condition is met.
- Correct tilted baseline coordinates, recording transformations and orientations.
- Identification of contact line motion states and phases for time-stamped sequences.
If the target involves hanging drop surface tension, a dynamic contact angle meter, or rough, porous, or absorbent materials, physical models, test setups, sample preparation, and reference methods need to be defined separately.
Input, output and result definitions
| Project | Main content | Need to confirm in project |
|---|---|---|
| Image and Silhouette | Original image, droplet outline, contact area | Pixel format, compression, edge visibility and occlusion |
| baseline | Baseline endpoints, directions, or repeatable extraction rules | Surface texture, tilt, reflection and contact point definition |
| contact angle | Left corner, right corner, average, method and status | Angle direction, fitting interval, unit and undecidable conditions |
| Geometric quantity | Circle or ellipse parameters, volume, surface area, residuals | Scaling, axial symmetry assumption and scope of application |
| Timing status | Contact radius, angle, speed and phase | Sampling time, gates, smoothing and event annotation |
The result interface should give the method, parameter version, input quality and status at the same time to avoid outputting only one angle value. When the baseline is unreliable, the contour is occluded, or the model residual exceeds the limit, it should return to an undecidable or degraded state.
How to choose the method route
| route | Applicable conditions | Main limitations |
|---|---|---|
| height-width method | Near-spherical crown, contour and scale stability | Not suitable for droplets that are significantly deformed by gravity |
| Circle or ellipse fitting | The overall contour approximates the corresponding geometric shape | Shape deviations and contact zone effects need to be checked |
| local polynomial or spline | Contact zone contours available, fitting windows definable | Sensitive to intervals, noise, and over-smoothing |
| ZuodiYoung-Laplace | Axisymmetric, static equilibrium and physical property conditions are available | Using Different Models and Acceptance Methods with Hanging Drop Surface Tension Inversion |
| Geometry and coordinate assistance | Requires axisymmetric integration or tilted baseline correction | Relies on correct contours and contact points |
| Timing status | Continuous time, radius, angle and threshold available | Status is affected by sampling rate and rules |
Multiple methods can be compared on fixed data for the same project, but comparisons are only interpretable if consistent profiles, baselines, reference readings, and statistical calibers are used.
Experimental and imaging conditions
Before evaluation, it is necessary to clarify whether the droplets are seat drops or other forms, and provide the camera direction, lens, backlight or outline lighting, field of view, pixel scale, substrate area, and test temperature and humidity. To explain wetting properties, information on fluids, substrates, cleaning treatments, and test timing is also required.
Representative data should cover normal contours, low contrast, baseline tilt, reflections, shadows, unclear contact points, droplet deflection, and morphological boundaries. Compressed images or cropped results can be used for preliminary screening, and formal verification should retain the original image and acquisition metadata.
Dynamic tasks require reliable timestamps. Without a time base, the frame number cannot be directly interpreted as a true velocity; without a scale, the physical volume or surface area cannot be output.
Verification methods and applicable conditions
Project validation checks contours, contact points, baselines, fitting residuals, left and right corner differences, repeatability, and abnormal status respectively. When physical quantity values are required, comparisons are made using agreed reference methods, test fluids, substrates and environmental conditions.
Angle error, repeatability, smallest measurable droplet, processing cycle time and platform compatibility are confirmed on the project sample and target equipment, and written into the acceptance record along with the method, scale, version and test conditions.
Project implementation and delivery
- Define experiments and outputs: Confirm droplet type, angle definition, baseline, scale, method route and downstream data format.
- Establish a sample baseline: Compare contours, contact points, and fitting residuals on representative images, recording undecidable conditions.
- Complete software adaptation: Access images or contours, parameter recipes, status codes, results export and version logging.
- Independent sample acceptance: Use data not involved in parameter selection to compare reference results, left and right angles, repeatability, failure rate, and time consumption.
Delivery may include algorithm programs or call libraries, interface descriptions, parameter files, sample and result lists, verification reports, and version notes. If camera control, motion mechanism, drip system, environmental control and complete machine certification need to be included, they will be listed separately in the project scope.
Acceptance suggestions
| Acceptance object | Recommended indicators | Conditions that must be recorded |
|---|---|---|
| Contours and Contact Points | Contour deviation, contact point consistency, failed samples | Image version, annotation or reference method, fitting interval |
| contact angle | Left and right angle errors, average and maximum differences, repeatability | Methods, baselines, scales, droplet and substrate conditions |
| Geometric quantity | Known geometric errors, units and sampling sensitivities | Axial symmetry assumptions, scales and integration ranges |
| Dynamic state | State consistency, event latency and threshold sensitivity | Timestamps, sampling rates, event annotations and filtering parameters |
| Exception handling | No contours, false baselines, occlusions, and residual out-of-limits | Status code, log and whether to enter manual review |
When project uses involve metrological reporting or laboratory quality systems, reference instruments, calibration status, method documentation, operators, and uncertainty requirements should be additionally confirmed.
Authorization, maintenance and changes
Algorithms can provide running licenses according to agreed devices, scenarios and versions. Annual services can cover original scene problem troubleshooting, parameter review, regression testing and controlled updates; adding new liquid systems, substrates, imaging devices, droplet models or output physical properties are scope changes.
The overall machine control software, source code, cross-platform adaptation and new method development are separately listed in the contract. The operating scope, period, replacement rules and service fees will be confirmed in writing after sample evaluation.
FAQ
Can a reliable contact angle be obtained directly from a picture of a droplet?
Reviewable results can only be calculated if the profile, baseline, scale and method assumptions are met. If the contact point is unclear, the reflection is blocked, or the shape is not suitable for the selected model, the test and imaging conditions should be returned to undeterminable or the test and imaging conditions should be changed.
What should I do if the angles given by multiple algorithms are inconsistent?
First check that they use the same contour, baseline, fitting interval and angle definitions, then compare the error and failure rate using independent references and real samples. The number of methods or the average of results cannot be used as a substitute for the basis for selection.
Can surface tension be obtained directly from a seat-drop diagram?
Cannot be used as a default capability. Surface tension or surface energy inversion requires corresponding physical models, liquid properties, scales, test conditions and verification; the seat drop contact angle module does not automatically form a complete hanging drop ADSA system.
Is dynamic contact angle supported?
Time-stamped sequences of contours, angles and contact radii can be evaluated and states identified by validation rules. Sampling rates, motion phase definitions and test setups need to be confirmed within the project.
Define the Development Scope with Samples and Device Requirements
Contact angle and droplet profile analysis algorithm services
Please describe the task object, original picture or video, target indicators, device platform, interface and sample situation.
Phone: 13910119357xuzhiyang0928@gmail.com