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Clean image backgrounds, margins and colors

Written by CovertonPublished Updated

Trimming empty space around a logo is different from removing a photograph’s background. Use margin trimming when the space is already transparent, and background removal when the background is part of the picture. Inspect icons at their final display size.

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Choose a background-removal method

Solid mode removes border-connected color. For complex photos, consider AI and compare hair, transparent products and fine edges with the source. AI mode requires WebGPU and a roughly 219 MB model download on first use.

Inspect effects at the size people will see

Rotation, grayscale, blur and borders do different jobs. A contact sheet arranges several images on one canvas. Do not assume blur securely removes private information; separately review the content of any file you plan to share.

Prepare icons and a usable palette

Trim transparent margins before making the favicon PNG bundle. It does not automatically produce every app or operating-system icon format. Palette extraction reports dominant HEX colors and proportions. Visual comparison finds pixel differences between two images with identical dimensions.

Choose the right tool

Example inputs illustrate the workflow; they do not promise a particular file size, recognition accuracy or compatibility.

Rotate and flip images

Rotate or mirror a photo into a new file. Check whether mirroring reverses text in the picture.

Example

photo + horizontal flip → mirrored copy
  1. Choose files in JPG, JPEG, PNG, WEBP, GIF, BMP, AVIF, ICO format. Maximum files per batch: 100.
  2. Review Output quality (%), Rotation (degrees), Flip, then start processing.
  3. Download the JPGPNGWEBP result and check its content and quality.
What to check

Re-encoding can change quality and metadata; mirroring is not the same operation as rotation.

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Convert images to grayscale

Represent a photo using shades of gray. Grayscale differs from thresholding into only black and white.

Example

color photo → grayscale photo
  1. Choose files in JPG, JPEG, PNG, WEBP format. Maximum files per batch: 100.
  2. Review Output format, Output quality (%), then start processing.
  3. Download the Image result and check its content and quality.
What to check

The output keeps tonal variation; it is not a one-bit black-and-white threshold image.

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Blur images

Blur an entire image for a background. This is not a region selector for hiding only a particular face.

Example

photo + blur amount → blurred whole image
  1. Choose files in JPG, JPEG, PNG, WEBP format. Maximum files per batch: 100.
  2. Review Blur amount, Output format, Output quality (%), then start processing.
  3. Download the Image result and check its content and quality.
What to check

Blur is applied to the whole frame. It is not selective face detection or secure redaction.

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Add borders to images

Add a border and corner treatment to a publishing copy. Check the border's effect on output dimensions.

Example

image + border width/color → bordered copy
  1. Choose files in JPG, JPEG, PNG, WEBP format. Maximum files per batch: 100.
  2. Review Border width (px), Color, Corner radius, then start processing.
  3. Download the Image result and check its content and quality.
What to check

The border becomes part of the exported raster image, not an editable graphic layer.

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Create an image contact sheet

Compare several designs on one sheet using column count and cell dimensions. Keep the individual source photos.

Example

4 photos + 2 columns → image grid
  1. Choose files in JPG, JPEG, PNG, WEBP format. Maximum files per batch: 100.
  2. Review Columns, Cell width (px), Cell height (px), then start processing.
  3. Download the PNGJPG result and check its content and quality.
What to check

Thumbnails are resized to the cells. Large grids can exceed the browser's canvas or memory limits.

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Create a favicon

Prepare website icon sizes from one image. Inspect whether the mark remains recognizable at small sizes.

Example

logo → 16/32/48/180/192/512 px icons
  1. Choose files in JPG, JPEG, PNG, WEBP, SVG format. Maximum files per batch: 1.
  2. Review Fit mode, Background color, Keep transparent background, then start processing.
  3. Download the Image result and check its content and quality.
What to check

Fine detail can disappear at small icon sizes. Review every generated size before using it on a site.

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Trim transparent image margins

Trim empty space around a transparent logo using an alpha threshold and padding. This does not remove an opaque white background.

Example

transparent logo with margins → trimmed logo
  1. Choose files in PNG, WEBP format. Maximum files per batch: 100.
  2. Review Alpha threshold (%), Padding (px), Output quality (%), then start processing.
  3. Download the PNG result and check its content and quality.
What to check

A white background is opaque and will not be removed. Higher thresholds can cut off faint edge pixels.

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Remove image background

Remove a connected solid background or use the supported AI path. Compare fine edges with the original.

Example

product photo → transparent/solid-background PNGOpen the tool →

Image diff

Inspect pixel changes between two equal-size designs. This does not judge semantic correctness.

Example

equal-size old/new images → pixel difference imageOpen the tool →

Extract an image color palette

Extract dominant colors from a reference picture. Reduced, quantized analysis is not precise color management.

Example

reference image → HEX/proportion CSV + CSS + palette PNGOpen the tool →

This guide describes the public web tools and their support limits. Keep your original and check the downloaded result. Coverton · Corrections and contact