```{image} ../src/orangecontrib/ewoks3dxrd/icons/image_gen.svg
:alt: Image Generation Widget Icon
:class: widget-title-icon
```
# Background and Mask Generation

Before processing your _3DXRD_ dataset, you will need correction images. The **Generate Image from Raw Data** widget loads a raw HDF5/NeXus image stack 
and processes it into a background/flat-field frame and/or a custom pixel mask.

:::{warning}
Please use only the scan with 100-500 frames
:::

---

## 1. Computing Background and Flat-Field Images

### Input Configuration
Double-click the widget node to open the control panel and configure your data inputs:

* **Master File**: Select your experiment's raw `.h5` or `.nx` data file. 
* **Detector**: The widget automatically parses the internal structure of the file and locks onto your active detector path. 
    If multiple detectors are found, select the target one from the dropdown list.
* **Scan Number**: Select the scan index containing your correction frame sequences. 
    If only one valid scan is detected, it will automatically be selected.


![Sample background Generated Image](_static/tuto/bkg_image_generation.png)

### Reduction Mode Execution
Because raw background data is loaded as a 3D frame stack ($N \times \text{height} \times \text{width}$), you must reduce the stack into a clean, 2D reference correction layer. 

Select your target math operation under **Reduction Mode** and click **Compute Image**:

* _AVERAGE_.
* _MAXIMUM_
* _MINIMUM_.
* _MEDIAN_.

Once calculated, the image is displayed on the right-hand panel. Click **Save Image File** save the image to disk as a `.edf` file.

---
## 2. Masking Pixels via Silx Tools

Click on the mask icon on the toolbar to open the `silx` mask tool. This tool allows to interactively draw a mask on the image.

![Mask Icon Click to draw and generate mask Image](_static/tuto/mask_image_generation.png)

### Drawing Custom Shapes
Use the toolbar options on the right to design the mask:
* **Selection Modes**: Toggle drawing profiles like *Rectangle*, *Polygon*, or *Freehand*.
* **Flag Regions**: Draw shapes across bad pixel clusters, high-intensity direct beam points, or the shadow of the beamstop to build your mask array.
* **Reset**: If a selection layout goes wrong, click **Clear Image** in your control box to strip all custom masks back to zero.
* **Threshold**: You can also use simple threshold mechanism (like min, max) to create mask image.