ImageData

ImageData[image]

gives the array of pixel values in an Image or Image3D object image.

ImageData[image,"type"]

gives the array of pixel values converted to the specified type.

Details and Options

  • ImageData[image] by default gives a 2D or 3D array whose elements are lists of values for each channel. For a single-channel image, only a value and not a list of values is returned.
  • In 2D, the array generated by ImageData[image] is arranged in the same way that the image is displayed, with the first row corresponding to the top row of pixels in the image.
  • In 3D, the array generated by ImageData[image] is arranged such that the first part corresponds to the top slice, with rows running from back to front, and columns running from left to right.
  • For binary images, ImageData[image] returns integer values 0 or 1. For images of type "Byte" or "Bit16", ImageData[image] always normalizes values to lie between 0 and 1. For images of a real type, ImageData[image] returns whatever real values are used in the image.
  • Possible types specified by ImageData[image,"type"] are:
  • "Bit"integer 0 or 1
    "Byte"integer 0 through 255
    "Bit16"integer 0 through 65535
    "Real32"single-precision real (32-bit)
    "Real64"double-precision real (64-bit)
  • ImageData[image,Automatic] is equivalent to ImageData[image,ImageType[image]].
  • ImageData has the option Interleaving.
  • With the default setting Interleaving->True, ImageData returns a 2D or 3D array of lists of channel values.
  • With Interleaving->False, ImageData returns a list of 2D or 3D arrays of values for each channel.
  • Interleaving->Automatic returns in the native form used to store the image.
  • ImageData accepts a DataReversed option. With DataReversed->True, the order of the rows is reversed.

Examples

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Basic Examples  (3)

Channel data for the first five pixels of the first row:

Construct a byte-valued image:

Extract normalized raster data:

Extract raw bytes:

Extract data from a 3D image:

Options  (3)

DataReversed  (1)

By default, data is returned from the top to the bottom:

Reverse the order of rows:

Interleaving  (2)

Data of multichannel images is by default returned in interleaved form:

This gives the pixel data in planar form:

Retrieve the image data in interleaved form:

Retrieve the image data in planar form:

Properties & Relations  (2)

ImageData and Raster assume a different ordering of the rows:

To visualize image data using Raster, the rows need to be reversed:

Wolfram Research (2008), ImageData, Wolfram Language function, https://reference.wolfram.com/language/ref/ImageData.html (updated 2012).

Text

Wolfram Research (2008), ImageData, Wolfram Language function, https://reference.wolfram.com/language/ref/ImageData.html (updated 2012).

CMS

Wolfram Language. 2008. "ImageData." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2012. https://reference.wolfram.com/language/ref/ImageData.html.

APA

Wolfram Language. (2008). ImageData. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/ImageData.html

BibTeX

@misc{reference.wolfram_2024_imagedata, author="Wolfram Research", title="{ImageData}", year="2012", howpublished="\url{https://reference.wolfram.com/language/ref/ImageData.html}", note=[Accessed: 21-November-2024 ]}

BibLaTeX

@online{reference.wolfram_2024_imagedata, organization={Wolfram Research}, title={ImageData}, year={2012}, url={https://reference.wolfram.com/language/ref/ImageData.html}, note=[Accessed: 21-November-2024 ]}