Reference
Image editing glossary
37 plain-language definitions of the formats, settings, and concepts you meet when compressing, resizing, converting, and editing images. Click any term to jump to a linked tool or guide.
- Aspect ratio
- The proportional relationship between an image’s width and height, written like 16:9 or 1:1. Keeping the aspect ratio locked while resizing prevents an image from being stretched or squashed.
- AVIF
- AV1 Image File Format, a modern image format that compresses far smaller than JPG at similar visual quality. Browser encoding support varies, so ImgSprint falls back to JPG on devices that cannot encode it.
- Base64
- A text encoding that represents binary image data as ASCII characters. It is used to embed images directly inside HTML or CSS as data URIs without a separate file.
- Batch processing
- Applying the same operation — compress, resize, convert, or watermark — to many images at once instead of one by one. ImgSprint tools run batches locally, with results downloaded individually or together.
- Bitmap (BMP)
- A raster image format that stores pixels without much compression, which produces large files. BMP is rarely used on the web and is usually converted to JPG, PNG, or WebP to reduce size.
- Compression
- Reducing an image file’s byte size. Lossy compression (JPG, WebP, AVIF) discards some visual data to save space; lossless compression (PNG) shrinks a file without removing any pixel data.
- Contrast
- The difference in brightness between the darkest and lightest parts of an image. Raising contrast makes shadows deeper and highlights brighter.
- Crop
- Removing the outer parts of an image to change its framing or aspect ratio. Cropping discards pixels, unlike resizing, which scales the whole image.
- DPI
- Dots per inch, a print density metric. A 35×45 mm passport photo at 300 DPI equals roughly 413×531 pixels. DPI does not change the pixel dimensions of an image.
- EXIF
- Exchangeable Image File Format, the metadata block photos carry: camera model, shutter settings, dates, and often GPS location. It is easy to strip with a browser-based EXIF remover before sharing.
- Favicon
- The small icon a browser shows next to a site’s name in tabs and bookmarks. A full set usually includes 16×16, 32×32, 48×48, and 180×180 PNG sizes plus a multi-size ICO.
- Fill / cover mode
- A resize mode that scales an image to fill a target frame, cropping the overflow so nothing is stretched. The default setting in ImgSprint resizing for squares and widescreen sizes.
- Fit / contain mode
- A resize mode that scales the whole image to fit inside a target frame, letterboxing the remaining space onto a solid background color.
- GIF
- A widely supported format famous for simple animations and limited to 256 colors per frame. Because of the color limit, still GIF images are usually converted to PNG or WebP.
- HEIC
- High Efficiency Image Container, the default photo format on iPhone and iPad. It keeps good quality at roughly half the size of JPG, but many apps and websites cannot open it without conversion.
- HEX color
- A way of writing colors as a six-digit code such as #0d9488, where pairs of digits represent red, green, and blue amounts. Image color pickers output this value for designers and developers.
- HSL
- Hue, Saturation, and Lightness, a color model that describes colors the way people think about them. Photo editors use it for natural-looking adjustments.
- ICO
- The icon file format used by Windows and browsers for favicons. It can store multiple sizes in one file, so a single ICO works at 16, 32, and 48 pixels.
- JPG / JPEG
- Joint Photographic Experts Group, the most widely supported lossy image format. It compresses photos into small files by discarding detail, so quality drops as file size shrinks.
- Layer
- A separate, stacked image element — a photo, text, or graphic — that can be moved, styled, and combined with others. Layers are the foundation of editors, watermarking, and collage tools.
- Lossy vs lossless
- Lossy compression (JPG, WebP, AVIF) permanently discards subtle data to shrink files; lossless compression (PNG) keeps every pixel exact but saves less space. Choose lossy for photos and lossless for sharp graphics and transparency.
- Metadata
- Hidden data inside a file that describes it, such as camera model, date taken, author, and GPS coordinates. Removing metadata is a key privacy step before sharing photos.
- Opacity
- How see-through a layer or watermark is, expressed from 0 (fully invisible) to 100 (fully solid). Lower opacity is often used to keep watermarks subtle.
- Palette
- The set of colors an image contains. Image color pickers extract palettes, which designers reuse as brand or site colors.
- Pixel
- The smallest unit of a digital image — a single colored square. Image dimensions are simply the number of pixels across and down, such as 1920×1080.
- PNG
- Portable Network Graphics, a lossless format that supports transparency. It is the best choice for logos, icons, and screenshots, though files are usually larger than JPG or WebP.
- Quality
- The trade-off setting for lossy formats, usually 0–100. Higher quality keeps more detail but creates bigger files; around 85–92 percent looks great for most photos.
- Resolution
- The pixel dimensions of an image, such as 1080×1080 or 1920×1080. Higher resolution captures more detail but produces larger files.
- Resize
- Changing an image’s pixel dimensions while scaling its content. Shrinking is safe and looks sharp; enlarging cannot add genuine detail, so results are smoothed.
- Rotate & flip
- Rotate turns an image around its center (90° steps or any angle); flip mirrors it horizontally or vertically. Both fix orientation without changing file type.
- Saturation
- The intensity of color in an image. Zero saturation produces grayscale, while high saturation makes colors vivid and punchy.
- Transparent background
- An area of an image with no color data, shown as a checkerboard and saved by formats that support alpha such as PNG, WebP, and AVIF. JPG cannot store transparency.
- Upscale
- Increasing an image’s pixel dimensions beyond its original size. Because no new detail exists, upscaling smooths the result and may add a slight sharpening pass.
- Vector vs raster
- Vector images (SVG) are built from math and scale infinitely without quality loss; raster images (JPG, PNG, WebP) are grids of pixels that soften when enlarged. Image tools on this site process raster images.
- Watermark
- A text or logo overlay placed on an image to mark ownership or branding. Watermarks can be positioned, resized, and given partial opacity.
- WebP
- A modern format engineered for the web. At the same visual quality it is typically 25–35 percent smaller than JPG, supports transparency, and works in every modern browser.
- Web application
- Software that runs in a browser with no install. Every ImgSprint tool is a web application that executes entirely on the user’s device.