RemoveBackground

RemoveBackground[image]

returns an image with an alpha channel where the background is transparent.

RemoveBackground[image,model]

uses foreground or background model specification.

Details

  • RemoveBackground works with arbitrary 2D and 3D images.
  • The model specification is used to indicate the foreground that is kept in the image or the background that is removed from the image.
  • Possible settings for the foreground or background model specification are:
  • specbackground specification spec
    {"Background",spec}background specification spec
    {"Foreground",spec}foreground specification spec
  • Different specifications spec may be useful for each image when separating foreground and background.
  • Specifications used for regions with almost uniform color are:
  • "Uniform"region of almost uniform color
    colregion of almost uniform color col
    markerspecify the region using a marker
    {…,d}allow amount d of variation from the specified color
  • Brightness specifications can be given by:
  • "Bright"brighter foreground or background
    "Dark"darker foreground or background
  • In-focus and out-of-focus separation:
  • "Blurred"blurred region
    {"Blurred",r}assume blur factor of r
  • Markers can be given as an image, a graphics object, or a list of points {{x1,y1},{x2,y2},…} in the standard image coordinate system, where x runs from 0 to width, y runs from 0 to height, and position {0,0} corresponds to the bottom-left corner of the image.
  • If an image already has an alpha channel, the result will have an alpha channel equal to the computed foreground map multiplied with the original alpha channel.

Examples

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Basic Examples  (2)

Remove the background of an image:

Remove the background of a given color:

Scope  (9)

Separate almost uniformly colored background:

Specify the color and threshold for uniform background detection:

Specify a marker for detecting the uniform background:

Markers can also be specified by a list of coordinates:

Remove blurred background:

Separate almost uniformly colored foreground:

Specify the color for uniform foreground detection:

Specify the marker for uniform foreground detection:

Remove background from a 3D image:

Generalizations & Extensions  (1)

Background and foreground may be completely separated at multiple steps:

Remove the light yellow background:

Remove the yellow background from the temporary image:

Applications  (5)

Highlight bacteria:

Segment an object specified by a marker:

Count birds in a picture by first removing the uniform background:

Extract the shape of each component:

Detect the background in an image and replace it with fully transparent pixels:

Compose the foreground on top of a different background:

Chroma key compositing or chroma keying is a common technique to remove the background (typically green) from an image or video:

Find the shade of the green used in the background:

RemoveBackground replaces green pixels of the image with fully transparent pixels:

Compose the foreground over a slightly blurred background to also get an out-of-focus effect:

Properties & Relations  (1)

The foreground mask is stored as the alpha channel:

Use AlphaChannel to extract it:

Replace the background with a different color:

Use a background image to fill the background:

Wolfram Research (2014), RemoveBackground, Wolfram Language function, https://reference.wolfram.com/language/ref/RemoveBackground.html.

Text

Wolfram Research (2014), RemoveBackground, Wolfram Language function, https://reference.wolfram.com/language/ref/RemoveBackground.html.

CMS

Wolfram Language. 2014. "RemoveBackground." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/RemoveBackground.html.

APA

Wolfram Language. (2014). RemoveBackground. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/RemoveBackground.html

BibTeX

@misc{reference.wolfram_2022_removebackground, author="Wolfram Research", title="{RemoveBackground}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/RemoveBackground.html}", note=[Accessed: 28-March-2023 ]}

BibLaTeX

@online{reference.wolfram_2022_removebackground, organization={Wolfram Research}, title={RemoveBackground}, year={2014}, url={https://reference.wolfram.com/language/ref/RemoveBackground.html}, note=[Accessed: 28-March-2023 ]}