Upsample

Upsample[array,n]

returns an upsampled version of the array by inserting zeros between array elements.

Upsample[array,n,offset]

shifts array so that its first element moves to the position offset in the resulting array.

Upsample[array,n,offset,val]

inserts elements of value val between array elements.

Upsample[image,…]

upsamples an image.

Details

  • In Upsample[array,…], array can be an array of any rank.
  • Upsample works with arrays of any rank and 2D and 3D images.
  • Upsample[array,{n1,n2,…}] inserts ni zeros between elements in the i^(th) dimension.
  • Upsample[array,n] is equivalent to Upsample[array,n,1].
  • In Upsample[array,n,offset], the offset has to be an integer between 1 and n.

Examples

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Basic Examples  (3)

Upsample a list by a factor of 3:

Use an offset:

Specify the value to be inserted:

Upsample a 2D array:

Upsample an image by a factor of 2:

Scope  (3)

Use a different upsampling factor in each dimension:

Upsample a symbolic array:

Upsample an image by a factor of 2:

By default, using offset equal to 1, no shifting is performed:

Use a larger offset:

Use a different offset in each dimension:

Specify the insertion value:

Applications  (3)

Create a Nyquist filter of length 7:

Upsample by a factor of 2 using the smoothing filter:

Linear interpolation using upsampling and convolution:

This implementation is not very efficient:

A faster implementation would merge convolutions of the signal with odd and even samples of the filter:

Linear interpolation by a factor :

Introduced in 2012
 (9.0)
 |
Updated in 2016
 (10.4)