# ImageAnnotationPreview

## Introduction

**`ImageAnnotationPreview`** is a widget for displaying image annotation.

## Function signature

```python
image_preview = ImageAnnotationPreview(
    annotations_opacity = 0.5,
    enable_zoom = False,
    line_width = 1,
)
```

![](https://github.com/supervisely-ecosystem/ui-widgets-demos/assets/48913536/6f29084d-c71e-47f0-a962-12ac2f472f23)

## Parameters

|       Parameters      |   Type  |                  Description                  |
| :-------------------: | :-----: | :-------------------------------------------: |
| `annotations_opacity` | `float` |           Opacity of the annotation           |
|     `enable_zoom`     |  `bool` |         If `True` allows to zoom image        |
|      `line_width`     |  `int`  | Width of the annotation border (contour) line |
|      `widget_id`      |  `str`  |                ID of the widget               |

### annotations\_opacity

Annotation opacity. Value must be between 0 and 1. Set to 0 to hide annotations.

**type:** `float`

**default value:** `0.5`

```python
image_preview = ImageAnnotationPreview(
    annotations_opacity = 1,
)
```

![](https://github.com/supervisely-ecosystem/ui-widgets-demos/assets/48913536/87d6b835-b6cd-4e66-9479-6114d2c86d7c)

### enable\_zoom

If `True`, allows to zoom image with the mouse wheel.

**type:** `bool`

**default value:** `False`

```python
image_preview = ImageAnnotationPreview(
    enable_zoom = True,
)
```

### line\_width

Width of the annotation border (contour) line. Set to 0 to hide line.

**type:** `int`

**default value:** `1`

```python
image_preview = ImageAnnotationPreview(
    line_width = 0,
)
```

![](https://github.com/supervisely-ecosystem/ui-widgets-demos/assets/48913536/88af91d5-45a2-4a5c-93fd-1adef1b3721e)

### widget\_id

ID of the widget.

**type:** `str`

**default value:** `None`

## Methods and attributes

| Attributes and Methods | Description                                     |
| :--------------------: | ----------------------------------------------- |
|         `set()`        | Set image and annotation to widget.             |
|      `clean_up()`      | Clean up widget from image.                     |
|      `is_empty()`      | Return bool value, whether image is set or not. |

## Mini App Example

You can find this example in our Github repository:

[supervisely-ecosystem/ui-widgets-demos/media/015\_image\_annotation\_preview/src/main.py](https://github.com/supervisely-ecosystem/ui-widgets-demos/blob/master/media/015_image_annotation_preview/src/main.py)

### Import libraries

```python
import os
from random import choice
import supervisely as sly
from dotenv import load_dotenv
from supervisely.app.widgets import Button, Card, Container, ImageAnnotationPreview
```

### Init API client

First, we load environment variables with credentials and init API for communicating with Supervisely Instance:

```python
load_dotenv("local.env")
load_dotenv(os.path.expanduser("~/supervisely.env"))

api = sly.Api()
```

### Initialize `Project ID`

```python
project_id = sly.env.project_id()
```

### Get Project ID and meta

```python
project_id = sly.env.project_id()
project_meta_json = api.project.get_meta(project_id)
project_meta = sly.ProjectMeta.from_json(project_meta_json)
```

### Get images from dataset

```python
dataset = api.dataset.get_list(project_id)[0]
images = api.image.get_list(dataset.id)
image = images[0]
```

### Get annotation for image

```python
ann_json = api.annotation.download(image.id).annotation
ann = sly.Annotation.from_json(ann_json, project_meta)
```

### Initialize ImageAnnotationPreview widget and set image with annotation and project meta

```python
image_preview = ImageAnnotationPreview(
    annotations_opacity=0.5,
    enable_zoom=False,
    line_width=1,
)
image_preview.set(
    image_url=image.preview_url,
    ann=ann,
    project_meta=project_meta
)
```

### Add button widget to show random image, we will use it later

```python
random_button = Button("Random image")
```

### Create app layout

Prepare a layout for app using `Card` widget with the `content` parameter and place widgets that we've just created in the `Container` widget.

```python
card = Card(
    title="ImageAnnotationPreview",
    content=Container([image_preview, random_button])
)
```

### Create app using layout

Create an app object with layout parameter.

```python
app = sly.Application(layout=layout)
```

![](https://github.com/supervisely-ecosystem/ui-widgets-demos/assets/48913536/990461f1-8f5c-4e12-9257-7fe36952e897)

### Add button click event to update preview

```python
@random_button.click
def set_random_image():
    random_image = choice(images)
    random_ann_json = api.annotation.download(random_image.id).annotation
    random_ann = sly.Annotation.from_json(
        random_ann_json,
        project_meta
    )

    image_preview.set(
        image_url=random_image.preview_url,
        ann=random_ann,
        project_meta=project_meta
    )
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://developer.supervisely.com/app-development/widgets/media/imageannotationpreview.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.