appium / appium/java-client

Image Comparison for Dynamic and Multilingual screen

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Description

Hi,
I am using Appium Images plugin to perform visual testing, I have found Similarity Calculation and Occurences Lookup to be particularly useful for my use case where I am comparing if a screen matches the baseline, and if a certain element screenshot is present as a subset of screen.
For multilingual apps, I have found one limitation is that it picks up the translation differences which results in reduced value of ComparisonResult. For example,
English Screen

Image

German Screen

Image

Similarity Result

Image

In case, where the baseline screenshot is the same language (English) then the similiarity score comes out to be 0.999995768070221 while when the baseline screenshot is in a different language (German) then the similarity is significantly low 0.8476240038871765 due to the different text on image.

To counter this difference, one approach would be to run tests against different locales in which baseline images stored for comparison correspond to the lanague of app under test. While this approach is helpful, it adds an overhead to run tests on multiple lanaguages and does not scale if no of supported languages is large.

This is also relevant for cases where the text is variable for example, name/address/price of an on-screen element can differ. While mocking the result to have always same values for image comparison can be done, this is not always the possibility and easier to achieve.

For such image comparison, I would like to have a feature that basically ignores any text on the screen when performing image similiarity. Would it be possible to have such an option in SimilarityMatchingOptions where this flag can be passed to either consider or ignore on-screen text together with a threshold value which decided if and how much on-screen text will be taken into account during image similarity check? Another idea is to pass element ID or screen coordinates which should be excluded from image comparison, maybe to mask/blackout them, this way we can manually pass elements which have dynamic text to be excluded for similiarity matching?

Or perhaps if this is not a possibility, would it be possible to achieve this visual testing without relying on external providers and only using Appium MCP with some sort of image comparison tooling either using Images plugin or via LLM native image models. There is a feature request I have also put up for https://github.com/appium/appium-mcp/issues/418. There is a tool available for finding elements using AI but not sure if it can be extnded to also use AI for image comparison.

If there is a rather more suitable approach that already exists, I would be also interested in trying it out. thanks

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reviewing SimilarityMatchingOptions and the linked Appium Images plugin documentation on similarity calculation and occurrence lookup. Compare the requested text exclusion, threshold, coordinate or element masking, and AI-based alternatives, then define one implementable scope and tests that demonstrate the intended multilingual and dynamic-text behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
java
Domain
computer-vision, testing-qa
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Quiet
Clarity
Needs clarification
Newbie friendliness
25/100

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