AI on Your Computer

Many of Chromatelier's AI features run entirely on your computer: selecting the subject and the sky, cutting out backgrounds, removing wires and passers-by, replacing the sky, enlarging images and removing noise. You download each model once – after that everything works offline, and your images never leave your computer.

How the local AI works

The AI models are not part of the program package, so that the Chromatelier download stays small. The first time you use a feature that needs a model, Chromatelier asks whether it should download the model. Each model comes from a fixed version and is checked against its checksum after the download. After that, it stays on your computer permanently.

• Download once, then offline: once a model is installed, you no longer need an internet connection for the feature.
• Nothing leaves your computer: the models run on your processor. No image and no information about your images is sent anywhere.
• In the background: longer calculations run in the background. At the bottom of the window you see a small bar with the progress, a seconds counter and the Cancel button. Only one AI task runs at a time.
• Undoing the result: every AI feature is a normal step in the history. You take it back with ⌘ Z.

Managing models

You see all models under Edit › Preferences… (⌘ K) in the Local AI section. Each row shows the name, size, license and the status Installed or Not installed. With Download you fetch a model in advance, and with Remove you delete it again and free up the disk space. Below the list is the folder where the models are stored.

The download dialog

If a feature is missing its model, the Local AI Model dialog opens. It names the model, the download size and the license, and reminds you that nothing from your images leaves your computer. If you click Download, Chromatelier downloads the model in the background and then starts the feature you wanted automatically. With Cancel, nothing happens.

Selecting with AI

Selecting the subject

Select › Subject selects the main subject of the image – usually a person, an animal or an object in the foreground. If the “Subject & Background” model is installed, it recognizes the subject with fine edges, even with hair. Without the model, the command uses a classic method without AI; the result is then coarser. The selection applies to the whole visible image, not just the active layer.

You can continue working with all the commands from the Selections chapter, for example with “Select and Mask…” for even finer hair edges.

Selecting the sky

Select › Sky selects the sky. With the depth model, Chromatelier looks for the most distant parts of the image that are connected to the top edge and combines them with a color analysis. That way towers, trees and wires are cleanly left out. Without the depth model, the command selects the sky based on colors only.

Selecting people: hair, skin, clothes

Select › People… finds all the people in the image and selects specific parts of them. The command needs two models: “Objects and People” for finding and “People: Hair, Skin, Clothes” for breaking them down into parts. In the Select People dialog you check what should go into the selection:

Typical uses: select only the hair and recolor it with an adjustment layer, only the skin for retouching, only the clothes for a color change. If the model finds no person, the status bar reports “No people found”.

Object Selection with Object Finder

The Object Selection tool (in the group with the Magic Wand, key W, cycle through the group with ⇧ W) has the Object Finder switch in the options bar. If it's on and the “Objects and People” model is installed, Chromatelier analyzes the image in the background. When you then move the pointer over the image, it outlines the object underneath in blue and shows its name, for example “person” or “car”.

• Clicking an outlined object selects it. For people, Chromatelier also uses the people model for a precise outline.
• Dragging a rectangle selects the object in the rectangle as usual – this works without the model too.
• The buttons New, Add, Subtract and Intersect as well as Sample All Layers work as they do with the other selection tools.

If the model is missing, the options bar shows the note “Object Finder: install the model in Preferences > Local AI”.

Remove Background

Layer › Layer Mask › Remove Background cuts out the subject of the active layer. Chromatelier doesn't delete any pixels: it creates a layer mask that hides the background. So you can touch up the mask with the brush, disable it or delete it at any time. The command needs the “Subject & Background” model and a pixel layer.

When there is no selection, the Contextual Task Bar below the image also offers the buttons “Select Subject” and “Remove Background” (show and hide it from the View menu).

Removing distractions

The Remove tool

The Remove (AI) tool is in the group with the Spot Healing Brush (key J, cycle through the group with ⇧ J). You paint over what should disappear – a passer-by, a sign, a stain. When you let go, the “Remove (MI-GAN)” model repaints the spot to match its surroundings. If several painted-over spots are far apart, it processes each one separately at full quality. An active selection limits the area.

If the model isn't installed, the options bar shows the Install the AI model… button. Without the model, the tool works like the Spot Healing Brush. You set the size, hardness and the other brush options as with any brush (see Tools).

Remove Selected (AI)

Edit › AI Tools › Remove Selected (AI) does the same for a selection: everything that is selected is repainted on the active layer. This is handy if you have already outlined the spot precisely with a selection tool, or if “Find Distractions” selected it for you.

Find Distractions

Under Edit › AI Tools › Find Distractions there are two commands that automatically select typical troublemakers. You then remove them with “Remove Selected (AI)” – that way you can check and correct the selection first.

If something is found, the status bar reports “Distractions selected: Edit > Remove Selected (AI) removes them”. If the command finds nothing, it shows something like “No wires or cables found”.

You proceed the same way with People. The main subject – the largest person in the foreground – stays untouched.

Sky Replacement

Edit › AI Tools › Sky Replacement… replaces the sky with a different one and adapts the foreground to the new light. The command works with documents in RGB Color mode and needs the depth model. After the dialog opens, Chromatelier first looks for the sky (“Finding the sky…”); after that you see every change immediately in the image.

Clicking OK creates a Sky Replacement Group with three layers: Sky (the new sky, limited to the sky area by a mask), Foreground Color and Foreground Lighting (they tint the rest of the image to match the new sky). All layers stay individually editable.

Face-Aware Liquify

The Filter › Liquify… dialog (⌘ ⇧ X) has the collapsible Face-Aware Liquify section. It finds faces with the small “Faces (YuNet)” model (0.2 MB). If it isn't installed yet, you download it there with Download the Face Model. The other tools of the dialog are described in the Filters chapter.

Once faces are found, if there are several people you choose “Face #1”, “Face #2” … (from left to right) in a list. For each face there are 16 sliders from −100 to 100:

Reset Face sets all sliders of the selected face to 0. You can combine the sliders with the dialog's brush tools.

Super Resolution

Image › Super Resolution… enlarges the image with the Real-ESRGAN model (4 MB) and invents fine details and clear edges in the process, instead of just upscaling pixels. In the dialog you choose the Factor 2× or 4×; the new size in pixels is shown below. The result opens as a new document with “enhanced” added to its name; your original stays unchanged. It works from the whole visible image.

The command refuses very large results (over 200 megapixels) with “Too large for Super Resolution”. With large images the calculation takes a while; the progress is shown at the bottom of the window.

AI Denoise

Filter › Local AI › AI Denoise… removes image noise from the active pixel layer with the SCUNet model. It smooths color and luminance noise but preserves edges and textures better than classic noise filters. The only slider, Amount (0–100 %, default 80 %), blends the denoised result with the original.

Depth blur with an AI depth map

The Filter › Blur › Lens Blur… filter simulates a shallow depth of field. If you set Depth Map to AI Depth Map there, the depth model estimates for each pixel how far away it is. With Blur Focal Distance you set which distance stays sharp; everything in front of and behind it becomes blurry according to the Radius. Invert swaps near and far. The depth map is calculated once per layer state and then reused.

The filter's iris shape, highlights and noise are described in the Filters chapter. The Depth Blur entry in Neural Filters leads directly to this filter.

Neural Filters

Filter › Neural Filters… brings the AI filters together in one dialog. On the left you choose the filter, on the right you set it up. Filters with a cloud icon send the image to OpenAI and need an API key – they are described in the Generative AI chapter. All the others work locally. The dialog remembers the settings from last time.

Neural Filters work with RGB and grayscale documents on a pixel layer. At the bottom of the dialog you choose the Output for each filter: New Layer (the default – the original is kept) or Current Layer. If a model is missing, the dialog shows “Needs …” in orange with the Install button.

Skin Smoothing

Skin Smoothing needs the “Faces” and “People” models. It first looks for all faces, determines the skin around them and smooths only those areas – eyes, eyebrows, lips and hair stay sharp. Blur (default 50) determines how strongly and over how large an area it smooths; Smoothness (default 0) makes the skin flatter or leaves more texture. If the filter finds no face, it reports “No faces found”.

Photo Restoration and JPEG artifacts

Photo Restoration combines three steps, each of which you can turn off by setting it to 0: Scratch Reduction (default 50) looks for fine scratches and dust spots and has the “Remove” model paint over them, Noise Reduction (default 30) denoises with SCUNet, and Photo Enhancement (default 40) improves the contrast automatically. Which models are needed depends on which sliders are above 0.

JPEG Artifact Removal also uses the denoising model. Choose the Strength to match the compression: Low for light artifacts, High for very strong ones.

Color Transfer and Harmonization

Both filters run directly in Chromatelier without a model. With Color Transfer, you load an image under Reference with Load… whose color mood you want to adopt. Harmonization takes everything below the active layer as its model – ideal when you have placed a cut-out object into another photo. That's why it only works with a layer that lies above an image. For both, you control the Strength; with Preserve Luminosity only the colors change, not the brightness.

Tips and error messages

• The models run on the processor. Large images therefore take time; Super Resolution and denoising split the image into tiles and show a progress bar.
• Wherever the AI has changed pixels (for example Remove, Denoise, Skin Smoothing), Chromatelier records this in the document's Content Credentials. More on this in the chapter Saving, Export & Printing.