Compositor for Windows 1.0

Published October 16, 2026

A picture is a stack of decisions. Where the subject sits. What stays sharp. What falls away behind it.

Compositor is the editor Robbie Tilton built for that work on the Mac. Version 1.0 is that editor on Windows 11: layers, masks, paint, type, adjustments, and a subject you can cut out on your own machine.

Hello,

The 0.1 builds were previews. 1.0 is the release. You open a picture, you stack the decisions, you save a project you can still edit tomorrow.

This is an independent port of Compositor 1.0.4, from upstream commit a19db901. Robbie made the original application and published the source. That work is the foundation, and it is still the reference we follow. He has not endorsed this Windows version. The original copyright and the MIT notices stay with the program.

The pin stays at a19db901. On Windows, the editor also follows the observable behavior from that baseline through Mac 1.4.5 where it applies here: the later blend modes, folder opacity, guides, finishing adjustments and filters, CPU layer effects, DirectWrite text, line shapes, and PSD, SVG, and RAW import. Rendering stays on the CPU and Direct3D paths.

A stack you can still edit

A composite falls apart the moment the only copy is a flattened JPEG. 1.0 keeps the stack.

A project is a .comp folder: a manifest and the image assets beside it. Copy the whole folder. Back up the whole folder. File > Export Image writes a flattened PNG or JPEG for the next application. The export is a picture. The project is the work.

What you can do

• Import a PNG, JPEG, TIFF, or HEIC, or start from File > New Canvas.
• Reorder layers, group them, clip them, hide them, and set opacity and blend mode. A folder can carry its own opacity, and that opacity multiplies what is inside it. The folder itself stays in Normal.
• The blend modes cover the original set and the later one: Linear Burn, Linear Dodge, Soft Light, Hard Light, Vivid Light, Linear Light, Pin Light, Hard Mix, Exclusion, Subtract, and Divide.
• Add a mask. White reveals, black hides, and the same paint tools edit the mask when its thumbnail is selected.
• Move and transform without throwing away the source pixels. A free-distortion draft has Apply and Cancel, and it resamples when you apply it. Escape cancels the gesture in progress. Ctrl+Z undoes a change that was committed.
• The Transform fields show position, size, and angle without trailing zeros.
• Adjustment layers keep their parameters in the stack, including Invert, Black & White, Color Balance, and blur or noise.
• Layer effects render on the CPU and stay on the layer: drop shadow, inner shadow, outer glow, inner glow, stroke, and color overlay. Color Overlay recolors the fill inside the alpha that is already there. A hidden effect keeps its settings. Cancel puts the layer back. OK is one undo step, and live text stays live.

The reader accepts project versions 1 through 13 and writes the lowest version that can represent the document. A plain document still saves as version 7. Paragraph alignment, tracking, leading, a text box, or a font style other than Regular raises the file to version 12. A 16-bit layer image raises it to version 13.

Put the subject where it belongs

Selecting, painting, and placing are the whole job. The tools are on the rail, and the shortcuts are the ones you already reach for.

What you can do

• Marquee, Lasso, Polygon, and Wand. Shift adds, Alt subtracts. With the wand active and no modifier, Tab switches between color and object selection. Object selection uses the bundled model.
• Brush, Eraser, Clone, Heal, and Retouch. The tip controls sit in the upper toolbar.
• Gradient holds a preview until Apply. Cancel or Escape drops it.
• Shape draws a rectangle, an ellipse, or a line. Shift+U switches the kind. Crop has an explicit Apply, with Free, Original, 1:1, 4:3, 3:4, 16:9, and 9:16. When a selection exists, a new crop starts from it.
• Ctrl+0 fits the canvas. Ctrl+1 is actual pixels. Hold Space and drag to pan. The wheel pans. Alt and a notch of the wheel zooms by 1.25 around the pointer.
• When part of the document is off-screen, a navigator sits at the bottom-right. It shows the whole composite and a rectangle for the view. Click or drag inside it to move. The picture catches up after editing pauses. A brush stroke keeps the current navigator picture until the stroke ends.
• Help > Command Palette… (Ctrl+Shift+P) lists the commands and tools that are bound right now. Arrows move the highlight. Enter runs the one you picked.

Type that stays type

Type is a layer, until you decide it should become pixels.

Click with the Type tool for point text. Drag at least 4 pixels and you get a paragraph box: the words wrap inside it, and the handles move or resize the box. They do not scale the type. The smallest side is 16 pixels. With the Move tool, double-click live text to edit it. Drag, or Shift-click, to highlight a range. Double-click a word to take that word. Escape throws the edit away. Ctrl+Enter, Done, or another tool commits it as one undo step.

The type bar sets the font, the style, the size, the alignment, the tracking, the leading, and the color. A selection that mixes faces shows Multiple. Hovering a face previews it. Leaving the menu without choosing restores the face you had. Several colors and faces in one layer are saved as runs. A later destructive pixel edit flattens the text.

DirectWrite draws the installed fonts. A Photoshop PostScript name maps to its DirectWrite family when that face is installed. A missing face is drawn with Segoe UI. Full justification comes in as left alignment. Vertical type, and type this editor cannot store, comes in as pixels.

Grade it, then decide

A grade you cannot undo is a grade you are afraid to try. Filters and adjustments preview first. Apply commits one undo step. Cancel puts the document back.

What you can do

• Tonal and color adjustments, blur, noise, lens correction, vignette, bloom, tonal contrast, dither, and scanlines, from the Image and Filters menus. A selection limits the pixel edit. A vignette can cover an empty layer.
• Filters > Camera Raw Filter replaces the pixels of the active image layer. It docks to the document window. It is not an adjustment layer, and the grade is not stored in the .comp project. While a slider moves, the preview is capped at 1024 pixels on the long edge, then refines to 2048. OK commits the full-resolution layer as one undo step named Camera Raw Filter. Hold Alt on Exposure, Highlights, or Whites to see highlight clipping, on Shadows or Blacks to see shadow clipping, and on Masking to see the sharpening mask.
• Guided Upright follows the two lines you draw. Those lines stay on the preview, aligned with the image while you zoom or pan, until Clear Guides, Cancel, or OK. There is no camera profile and no kelvin preset.
• Filters > Last Filter (Ctrl+Alt+F) repeats the last filter you applied from the Filters menu, with the same settings, as one undo step. The menu shows the name it remembered. Adjustments from the Image menu, and Content-Aware Fill, stay out of that memory. The choice is not written into the project.
• Each project remembers the filter settings you last applied. Cancel keeps the memory you already had. A new Gradient Map starts from the current foreground and background colors.

Cut the subject out here

Remove Background runs on your machine. The model is in the package. There is no account, and first launch does not download one.

Basic takes the model's first mask. Advanced opens refinement, edge shift, and contrast. Apply creates or updates a layer mask, and that mask is undoable. A result with no subject leaves the image as it was.

Hair, fur, and fine strands can keep a fringe of the old background. Transparent things, such as soap bubbles, can lose their look. Advanced is not always a cleaner edge. Textured backgrounds can be ambiguous. Look at the mask before you trust it, and paint the mask when the model stops.

The files on the disk

File > Open Project and the welcome Open project button use the Windows folder picker. They start in Downloads, and you can select one or more .comp folders. File > Import Image, the welcome Import image button, Export Image, and the first Save open Windows Explorer. An untitled save starts in Downloads. Save Project As starts in the current project folder when that folder is still there. If a picker is already open, the status bar says so, and the second request is ignored.

PNG export keeps transparency. JPEG uses the matte and the quality you chose. A JPEG name that ends in .png is written as .jpg. A PNG name that ends in .jpg or .jpeg is written as .png. A name that already has the right extension is left alone. Export stops at 30,000 pixels on a side and 100 million pixels in total.

8-bit and 16-bit RGB PSD and PSB files can come in with their layer names, stacking order, visibility, and canvas positions. Simple horizontal type can arrive as editable text, with family, size, color, and alignment. ZIP-compressed channels and layer masks are kept. A rounded rectangle is ...

Compositor for Windows 0.1.8

This independent Windows 11 x64 preview continues from 0.1.7. It is based on Compositor 1.0.4 by Robbie Tilton at a19db9011282399785dc18efcfded904627bdcc2. The port does not imply upstream endorsement, and full Mac equivalence is not claimed.

Rulers and guides

Horizontal and vertical rulers sit at the edges of the canvas and show document pixels. The numbers stay aligned with the image at fit, at actual pixels, and after zooming or panning. View → Rulers (Ctrl+R) hides or shows them. They are visible by default, and hiding them returns that margin to the canvas.

Drag from the top ruler to add a horizontal guide, or from the left ruler to add a vertical guide. Drag a guide to move it; its position is shown while the pointer moves. Releasing the pointer commits one undo step. Escape cancels the drag. Releasing a new guide back on its ruler, or releasing a guide outside the document on its axis, cancels it and leaves the document unchanged. Opening a project shows the guides saved in it. View → Guides shows or hides them and adds one at the vertical center when the document has none. View → Snap includes those guides while transforming.

Limits

Downloads are unsigned. Updates are manual. Full Mac equivalence, reciprocal .comp exchange, and Photoshop compatibility remain unverified. Keep a copy of each complete .comp directory. See KNOWN-ISSUES.md for brush performance, background removal, and the checks that have not been run on a fresh Windows install.

Compositor for Windows 0.1.7

This independent Windows 11 x64 preview continues from 0.1.6. It is based on Compositor 1.0.4 by Robbie Tilton at a19db9011282399785dc18efcfded904627bdcc2. The port does not imply upstream endorsement, and full Mac equivalence is not claimed.

Navigator

When zoom or pan leaves part of the document off-screen, a navigator appears at the bottom-right of the canvas. It shows the whole composite and a rectangle for the visible area. Click or drag inside it to move the view. The picture updates shortly after editing pauses. A brush or retouch stroke keeps the current picture until the stroke ends. Fit (Ctrl+0) hides it when the whole document is on screen.

The mouse wheel pans, including with Ctrl. Alt and rolling the wheel forward zooms in, and backward zooms out, around the pointer. One notch multiplies or divides the zoom by 1.25.

Layers and Camera Raw

Dragging a layer keeps that layer on screen while its preview finishes. A later drag does not reuse the previous layer's preview. Auto-select layer starts checked.

Camera Raw guided-upright lines stay visible on the preview, aligned with the image while zooming or panning, including a moved, rotated, or flipped layer. Clear Guides, Cancel, and OK remove them. The upright calculation is unchanged.

Limits

Downloads are unsigned. Updates are manual. Full Mac equivalence, reciprocal .comp exchange, and Photoshop compatibility remain unverified. Keep a copy of each complete .comp directory. See KNOWN-ISSUES.md for brush performance, background removal, and the checks that have not been run on a fresh Windows install.

Compositor for Windows 0.1.6

This independent Windows 11 x64 preview continues from 0.1.5. It is based on Compositor 1.0.4 by Robbie Tilton at a19db9011282399785dc18efcfded904627bdcc2. The port does not imply upstream endorsement, and full Mac equivalence is not claimed.

Command palette

Help → Command Palette… or Ctrl+Shift+P lists currently bound commands and tools. Type to filter, use the arrow keys to move the highlight, and press Enter to run the selected command.

Text, import, and filters

• A partial text selection stays on the chosen glyphs, and the type menus keep the chosen font and style.
• PSD and PSB import keeps Unicode layer names, converts 16-bit RGB channels to 8-bit, and imports individual layers from 16-bit files. When layer records cannot be decoded, the merged composite is imported and the import report lists the substitution. An installed Photoshop PostScript name maps to its DirectWrite family.
• Welcome Import image, File → Import Image, Export Image, and Save Project open in Windows Explorer. An untitled import or save starts in Downloads. Save Project As starts in the current project folder. A second picker is refused. A JPEG name ending in .png is written as .jpg, and a PNG name ending in .jpg or .jpeg is written as .png.
• Live text rows and the Type tool show an Aa glyph.
• Filters → Last Filter (Ctrl+Alt+F) repeats the last Filters-menu apply with the same settings, as one undo step. Image-menu adjustments and Content-Aware Fill are not remembered.
• While a Camera Raw slider is moving, the preview is limited to 1024 pixels on the long edge and then refines to 2048. OK still commits the full-resolution layer.
• Color Overlay recolors a layer inside its existing alpha.

Limits

Downloads are unsigned. Updates are manual. Full Mac equivalence, reciprocal .comp exchange, and Photoshop compatibility remain unverified. Keep a copy of each complete .comp directory. See KNOWN-ISSUES.md for brush performance, background removal, and the checks that have not been run on a fresh Windows install.

Compositor for Windows 0.1.5

This independent Windows 11 x64 preview continues from 0.1.4. It is based on Compositor 1.0.4 by Robbie Tilton at a19db9011282399785dc18efcfded904627bdcc2. The port does not imply upstream endorsement, and full Mac equivalence is not claimed.

Text and layers

• Type on the canvas with a caret. Double-click live text with the Move tool to edit it. Drag to highlight a range, double-click a word, and use Ctrl+Left or Ctrl+Right to move by word.
• Drag the Type tool to create a paragraph box. Corner and edge handles move or resize the box without scaling the type.
• The type bar sets the font, style, size, alignment, tracking, leading, and color of the selection. Several colors and faces in one layer are saved as text runs.
• Paragraph alignment, tracking, leading, a text box, and a non-regular font style are stored as project version 12. A document that does not use them stays on an older version.
• The Layers panel Effects menu adds a drop shadow, inner shadow, outer or inner glow, stroke, or color overlay without discarding live text. These effects are rendered on the CPU.
• Layer → Duplicate Layer is Ctrl+Shift+J. Ctrl+J remains Layer via Copy.

Photoshop import

8-bit RGB PSD and PSB files can import simple horizontal type as editable text, including family, size, color, and alignment. A missing font is drawn with Segoe UI. Full justification becomes left alignment. Vertical type, and type this editor cannot store, is imported as pixels. CMYK files are rejected. There is no PSD or PSB export.

Camera Raw Filter

Filter → Camera Raw Filter replaces the pixels of the active image layer. It is not an adjustment layer, and the grade is not stored in the .comp project. The panel docks to the right edge of the document window. OK commits one undo step named Camera Raw Filter and remembers the grade until the project closes. Cancel leaves both the pixels and the remembered grade unchanged. An unchanged grade adds no undo.

Hold Alt while dragging Exposure, Highlights, or Whites to preview highlight clipping, while dragging Shadows or Blacks to preview shadow clipping, and while dragging Masking to preview the sharpening mask. The white-balance, point-color, and defringe droppers, and guided upright lines, are sampled on the canvas.

There is no camera profile or kelvin preset. Guided Upright follows the drawn lines rather than a vanishing-point fit, and those guide lines are not drawn. Geometry is a CPU homography.

Limits

Downloads are unsigned. Updates are manual. Full Mac equivalence, reciprocal .comp exchange, and Photoshop compatibility remain unverified. Keep a copy of each complete .comp directory. See KNOWN-ISSUES.md for brush performance, background removal, and the checks that have not been run on a fresh Windows install.