# How to edit part of a photo with masks and AI tools

> In the Windows Editor tab, add a mask (subject, sky, brush and more) to change one part of a photo, or use AI tools to erase, blur, relight or replace a sky.

Source: https://firelet.media/help/masks-and-ai-photo-edits
Published: 2026-11-08 · Updated: 2026-11-08
Applies to: Windows

To edit just part of a photo in firelet.media Gallery, open the **Editor** tab ([[Ctrl]]+[[3]], Windows) and add a mask: the subject, the sky, the background, an object you click, or an area you paint or drag. Then move that mask's sliders. The **AI tools** go further: erase things, change the background, blur it like a portrait lens, relight the scene or replace the sky.

## Masks: local adjustments in a few clicks

A mask picks out an area, and the sliders under it change only that area. The rest of the photo stays as it is. You might brighten a face, darken a sky or warm up a foreground.

### Add a mask

1. Open the photo in the Editor and click **Masks** to open the section.
2. Under **New mask**, choose the kind of mask (see the table below).
3. For **Subject**, **Sky** and **Background**, wait a moment while the AI finds the area. For the others, draw it on the photo, then press [[Esc]] when you're done.
4. Check the red overlay: it shows what the mask covers. Untick **Show overlay** to see the photo plainly.
5. Move the mask's sliders: **Exposure**, **Contrast**, **Highlights**, **Shadows**, **Whites**, **Blacks**, **Clarity**, **Texture**, **Dehaze**, **Temperature**, **Tint** and **Saturation**.

| Mask | How you make it |
|---|---|
| **Subject** | Found by AI: the main person, animal or thing |
| **Sky** | Found by AI from the photo's depth |
| **Background** | Found by AI: everything but the subject |
| **Object** | "Click the object; Alt+click to leave a part out." |
| **Brush** | "Paint on the photo." Set **Size**, **Feather** and **Flow** first. |
| **Linear** | "Drag from where the effect is full to where it fades out." Good for a sky or a foreground. |
| **Radial** | "Drag from the centre outwards." Good for a spotlight or a soft vignette. |

### Refine a mask

Each mask gets a line in the list, such as "Subject 1". Select it to change it:

- **Add to mask** adds another piece, of any kind. A subject plus a brushed-in hat, for example.
- **Subtract from mask** cuts a piece out. Brush away an area the AI took by mistake.
- **Invert** swaps what is inside and outside the mask.
- **Delete mask** removes it.

You can add as many masks as you need, each with its own sliders.

## AI tools

The **AI tools** section has six tools. They all run on your PC, and a tool that needs an AI model asks before downloading it the first time.

### Smart enhance

Click **Suggest three**. The gallery builds three edits on top of **Auto**, such as **Balanced**, **Clear** or **Punchy**, and shows each as a small tile. Click the one you like; your sliders take its values, so you can fine-tune from there. With [AI search](https://firelet.media/help/index-library-for-ai-search) installed, the tiles are ranked by their aesthetic score, shown with a star.

### Magic eraser

1. Click **Erase…** and set **Size**.
2. Brush over a person or object you want gone.
3. Let go. The area is filled in from its surroundings.

Each stroke is filled when you let go, and **Undo** takes back the last one.

### Background

Choose **A colour** (**White**, **Light grey**, **Black**, **Cream**, **Blue** or **Green**), **Blurred** or **Removed (transparent)**, then set **Amount**. **As it is** turns it off. For a cut-out, [export](https://firelet.media/help/export-photos) as PNG to keep the transparency.

### Portrait blur

Raise **Blur** to soften what is behind (and in front of) your subject, the way a wide-aperture lens would. The subject itself stays sharp. **Focus on the subject** is on at first; untick it and set **Focus distance** to choose the sharp distance yourself.

### Relight

Click **Place the light**, then click the photo where the light should come from. Set **Strength**, **Warmth** (cooler or warmer) and **Ambient**, which darkens or brightens the whole scene. The gallery works out the scene's depth, so nearer things facing the light gain the most.

### Sky

**Boost** makes the sky deeper, richer and clearer. Under **Replace the sky**, pick one of 12 built-in skies, such as **Blue**, **Golden**, **Storm** or **Night**, or **Your photo…** to use a sky you shot yourself. **Amount** blends it in.

## The one-time downloads

The first time you use a tool, the gallery asks: "needs its AI model, a one-time download of … MB. It then works offline on this PC." The size depends on the tool. Say no and it won't ask again until you restart the gallery.

| Tool | Model it downloads |
|---|---|
| Subject and Background masks, Background, Portrait blur | Subject and background |
| Sky mask, Sky, Portrait blur, Relight | Depth |
| Object mask | Click to select |
| Magic eraser | Magic eraser |

On a PC with little free memory, the gallery uses a lighter subject model instead, with slightly softer edges. The tools run on the processor; the subject takes a few seconds on a typical photo.

> [!NOTE]
> Nothing about your photos is uploaded. The models come from the internet once; after that the tools work with no connection at all. See [what data does firelet.media Gallery send?](https://firelet.media/help/what-data-is-sent)

## Where AI edits are kept

The eraser's fills and the AI's maps are kept beside the library, in the `ai` folder under `%LOCALAPPDATA%\PictureGallery`. Your photo file is never changed, and **Undo** or **Reset** takes the change away.

If you'd rather have a separate file, open **Library** ([[Alt]]+[[1]]) and tick **AI edits make a new photo**. The magic eraser and background changes then write a new photo next to the original, named like `photo (erased).jpg` or `photo (background).png`, and open it in the Editor.

> [!TIP]
> Masks travel with **Sync…**. Make a sky mask on one photo, then sync it to the rest of a sunset series: each photo gets its own sky, found afresh. Object masks stay with their own photo. [How to use the Editor tab](https://firelet.media/help/use-the-editor-tab) shows how to sync.

## Questions

### Are my photos sent anywhere for the AI tools?

No. Each tool downloads its model once, after asking, and then runs on your PC. Your photos never leave it.

### Does the magic eraser change my file?

No. The fill is kept beside the library and drawn over the photo. Undo or Reset takes it away at any time.

### How do I get a cut-out with a transparent background?

Set Background to 'Removed (transparent)', then export as PNG. A JPEG export puts the subject on white.