Know what the
control changes.
Short definitions for the terms that affect your next edit. Follow the source when you need the formal specification.
- Alpha channel
- Coverage information stored alongside color. It lets a raster contain transparent, partially covered and opaque areas. A format that supports alpha can still contain an entirely opaque image. Source ↗
- Alpha matte
- A coverage map used when combining a foreground with a background. A useful matte needs more than a tidy outer silhouette when hair or transparent materials mix with the original scene. Source ↗
- Aspect ratio
- The relationship between width and height. It describes shape rather than resolution. Different pixel dimensions can have the same ratio. Source ↗
- AVIF
- An image format that a browser may be able to display without being able to encode through canvas. Check the actual direction of conversion. Source ↗
- Backdrop
- The surface or scene behind a subject. In the editor it can be transparent, a color, a blurred original or a selected image. Source ↗
- Batch processing
- Applying a workflow to a collection of files. Repeated settings do not remove the need to inspect each automatic mask and final export. Source ↗
- Bit depth
- The precision used to represent channel values. A higher source precision does not imply that every later browser operation preserves the entire source representation. Source ↗
- Blob
- A browser object holding data such as an encoded image. The returned type should be checked before assigning a download extension. Source ↗
- BMP
- A bitmap image format. Browser decoding can allow conversion to a more convenient delivery format, with the downloaded copy checked afterward. Source ↗
- Bounding box
- A rectangle around the selected subject. A missing detail or retained background fragment can make an automatic subject box misleading. Source ↗
- Browser cache
- Browser-managed storage that may retain downloaded assets. Availability and retention are not guaranteed, so caching does not establish complete offline support. Source ↗
- Canvas
- A browser drawing surface used here for local image composition and export. It is a working raster, not an archive of every field in the source file. Source ↗
- Checkerboard
- A display pattern used to reveal transparency. A screenshot containing the pattern is an opaque picture of that pattern, not a transparent download. Source ↗
- Chroma
- The color component of an image representation, distinct from brightness. Compression behavior can affect colored detail differently from broad brightness structure. Source ↗
- Clipping
- Excluding content outside a boundary. In a crop, important subject parts can be lost even when the resulting file has valid dimensions. Source ↗
- Color profile
- Information describing how color values should be interpreted. Preserving visible pixels is not a promise to preserve every profile or metadata field. Source ↗
- Color space
- A defined system for interpreting color values. sRGB is a common reference encoding, not a file extension. Source ↗
- Compositing
- Combining foreground and background according to coverage. The result can be opaque even when the original foreground asset had transparency. Source ↗
- Compression
- Encoding image data into a stored representation. File size and visual impact depend on content, dimensions, format and encoder settings. Source ↗
- Crop
- Selecting a smaller region of an image. Cropping removes content rather than adding missing scene information. Source ↗
- Decode
- Turn an encoded image into pixels that the application can use. Source decoding and destination encoding are separate capabilities. Source ↗
- DPI
- Dots per inch, often used loosely for image print density. Keep printer dots, raster pixels and physical dimensions distinct when preparing a print. Source ↗
- Edge softness
- A control that changes the transition around a mask boundary. It cannot reconstruct missing detail or independently remove background color mixed into edge pixels. Source ↗
- Encode
- Write a raster into an image format. A successful request must be checked against the returned type when the browser can fall back to another format. Source ↗
- Export
- Create a delivery copy from the current workspace. An export is not necessarily an editable project or metadata-preserving original. Source ↗
- Fit inside
- Scale an image proportionally to fit within a canvas, leaving margins when the ratios differ. It preserves the complete source rectangle. Source ↗
- Foreground
- The subject or region intended to remain visible. An automatic model can choose incorrectly when several objects compete for attention. Source ↗
- GIF
- An image format that can contain animation. This editor converts animated sources to a still raster rather than preserving their sequence. Source ↗
- Halo
- A visible fringe around a composited subject. It can come from selection errors, mixed background color or an overly broad edge transition. Source ↗
- HEIC
- An image-container extension commonly encountered in phone photos. This tool relies on native browser decoding and reports unsupported sources clearly. Source ↗
- Inference
- Running a trained model on an input to obtain a prediction. Here, it produces a foreground mask locally on the device. Source ↗
- Interpolation
- Estimating samples when resizing a raster or mask. More output samples do not mean more observed source detail. Source ↗
- JPEG
- A widely used opaque photographic delivery format. The JPEG path here places transparent areas on white before encoding. Source ↗
- Lossless
- An encoding property that preserves the raster supplied to that step. It cannot reverse damage already present in the supplied pixels. Source ↗
- Lossy
- An encoding approach that changes the represented image to reduce data. Inspect the actual export rather than treating a quality value as a universal score. Source ↗
- Mask
- A map controlling which source pixels contribute to the composition. Erase and Restore edit this coverage rather than generating a new subject. Source ↗
- Matting
- Estimating foreground coverage at mixed boundaries. Hair and transparent objects can require more than a broad subject selection. Source ↗
- Megapixel
- A count of one million pixels. It measures raster sample count, not compressed file size or guaranteed useful detail. Source ↗
- Metadata
- Information associated with an image file beyond its visible raster. Browser re-encoding should not be assumed to preserve or remove every field. Source ↗
- MIME type
- A label identifying the returned data format. Checking it helps prevent an unsupported encoder fallback from being saved under the wrong extension. Source ↗
- ONNX
- A model representation used by the runtime in this app. The pinned graph, preprocessing and execution path together determine the implemented behavior. Source ↗
- Padding
- Space around the subject inside the output canvas. Padding cannot recover content that was clipped before the photo was captured. Source ↗
- Pixel
- A sample in a raster grid. Width and height determine how many samples the image contains, while encoding determines stored bytes. Source ↗
- PNG
- A lossless raster format that supports alpha. A PNG file can preserve a transparent cutout or contain an entirely opaque background. Source ↗
- PPI
- Pixels per inch, relating raster dimensions to an intended physical print size. It does not by itself establish source sharpness or printer scaling. Source ↗
- Raster
- An image represented as a grid of samples. Enlarging the grid does not turn it into resolution-independent vector artwork. Source ↗
- Resampling
- Creating a different sampling grid during resizing. Keep the original so that later outputs do not depend on an already reduced copy. Source ↗
- Segmentation
- Estimating which image regions belong to a subject or class. A selected glass outline does not necessarily separate the scene visible through it. Source ↗
- sRGB
- A standard color encoding recorded by the International Color Consortium. It gives meaning to channel values and is separate from the file format. Source ↗
- WASM
- WebAssembly, used by the app as a local execution fallback. It does not mean that the image is sent to a server. Source ↗
- WebGPU
- A browser API for GPU work where supported. A capability check and a tested fallback are needed because availability is environment-dependent. Source ↗
- WebP
- An image format supporting transparent and opaque delivery. Check encoder availability and the receiving application before choosing it. Source ↗
Sources & method
Last checked: . Official rules can change. Calculated presets are identified separately.
- PNG Specification, Third Edition. W3C. Checked 2026-10-29.
- Is a Green Screen Really Necessary for Real-Time Portrait Matting?. Zhanghan Ke et al.. Checked 2026-10-29.
- Published tool specifications. Backdropless. Checked 2026-10-29.
- Image file type and format guide. MDN Web Docs. Checked 2026-10-29.
- HTMLCanvasElement.toBlob. MDN Web Docs. Checked 2026-10-29.
- sRGB encoding registry. International Color Consortium. Checked 2026-10-29.
- SI Units: Length. NIST. Checked 2026-10-29.
- U2-Net: Going Deeper with Nested U-Structure. Xuebin Qin et al.. Checked 2026-10-29.
- Actual model evaluation. Backdropless. Checked 2026-10-29.
- Environment flags and session options. ONNX Runtime. Checked 2026-10-29.
- Pixel manipulation with canvas. MDN Web Docs. Checked 2026-10-29.
- WebGPU API. MDN Web Docs. Checked 2026-10-29.