# Rules of Assigning Analyses

Analyses in Oz system can be applied in two ways:

* manually, for instance, when you choose the Liveness scenario in our demo application;
* automatically, when you don’t choose anything and just assign all possible analyses (via API or SDK).

The automatic assignment means that Oz system decides itself what analyses to apply to media files based on its [tags](https://doc.ozforensics.com/oz-knowledge/guides/developer-guide/api/oz-api/media-tags) and type. If you upload files via the web console, you select the tags needed; if you take photo or video via Web SDK, the SDK picks the tags automatically. As for the media type, it can be `IMAGE` (a photo)/`VIDEO`/`SHOTS_SET`, where `SHOTS_SET` is a .zip archive equal to video.

Below, you will find the tags and type requirements for all analyses. If a media doesn’t match the requirements for the certain analysis, this media is ignored by algorithms.

The rules listed below act by default. To change the mapping configuration, please [contact us](mailto:info@ozforensics.com).

### [Quality (Liveness)](https://doc.ozforensics.com/oz-knowledge/guides/developer-guide/api/types-of-analyses-and-what-they-check#quality-liveness-best-shot) <a href="#h.u3oofd1yob8x" id="h.u3oofd1yob8x"></a>

This analysis is applied to all media, regardless of the [gesture](https://doc.ozforensics.com/oz-knowledge/general/readme/passive-and-active-liveness) recorded (gesture tags begin from `video_selfie`).

**Important**: to process a photo in API 4.0.8 and below, pack it into a .zip archive, apply the `SHOTS_SET` type, and mark it with `video_*.` Otherwise, it will be ignored.

### [Biometry](https://doc.ozforensics.com/oz-knowledge/guides/developer-guide/api/types-of-analyses-and-what-they-check#biometry) <a href="#h.cof1fpf9g1n9" id="h.cof1fpf9g1n9"></a>

This analysis is applied to all media.

If the folder contains less than two matching media files, the system will return an error. If there are more than two files, then all pairs will be compared, and the system will return a result for the pair with the least similar faces.

### [Collection](https://doc.ozforensics.com/oz-knowledge/guides/developer-guide/api/types-of-analyses-and-what-they-check#blacklist) <a href="#h.a3bckcn8f9x5" id="h.a3bckcn8f9x5"></a>

This analysis works only when you have a pre-made image database, which is called collection. The analysis is applied to all media in the folder (or the ones marked as source media).

### [Best Shot](https://doc.ozforensics.com/oz-knowledge/guides/developer-guide/api/types-of-analyses-and-what-they-check#quality-liveness-best-shot) <a href="#h.qiipj36r6mhw" id="h.qiipj36r6mhw"></a>

Best Shot is an addition to the Quality (Liveness) analysis. It requires the appropriate option enabled. The analysis is applied to all media files that can be processed by the Quality analysis.

### [Documents](https://doc.ozforensics.com/oz-knowledge/guides/developer-guide/api/types-of-analyses-and-what-they-check#documents) <a href="#h.6wezm218un2o" id="h.6wezm218un2o"></a>

{% hint style="info" %}
This analysis type is deprecated.
{% endhint %}

The Documents analysis is applied to images with tags `photo_id_front` and `photo_id_back` (documents), and `photo_selfie` (selfie). The result will be positive if the system finds the selfie photo and matches it with a photo on one of the valid documents from the following list:

* personal ID card
* driver license
* foreign passport

### Tag-Related Errors

| **Code** | **Message**                                                       | **Description**                                                                                                                                                             |
| -------- | ----------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 202      | Could not locate face on source media `[media_id]`                | No face is found in the media that is being processed, or the source media has wrong (`photo_id_back`) or/and missing tag used for the media.                               |
| 202      | Biometry. Analysis requires at least 2 media objects to process   | The algorithms did not find the two appropriate media for analysis. This might happen when only a single media has been sent for the analysis, or a media is missing a tag. |
| 202      | Processing error - did not found any document candidates on image | The Documents analysis can't be finished because the photo uploaded seems not to be a document, or it has wrong (not `photo_id_*`) or/and missing tags.                     |
| 5        | Invalid/missed tag values to process quality check                | The tags applied can't be processed by the Quality algorithm (most likely, the tags begin from `photo_*`; for Quality, they should be marked as `video_*`)                  |
| 5        | Invalid/missed tag values to process collection check             | The tags applied can't be processed by the Collection algorithm. This might happen when a media is missing a tag.                                                           |