machinevisiontoolbox.Image.scale

Image.scale(sfactor, sigma=None, interpolation=None)

Scale an image

Parameters:

  • sfactor (scalar) – scale factor

  • sigma (float) – standard deviation of kernel for image smoothing, in pixels

Raises:

  • ValueError – bad interpolation string

  • ValueError – bad interpolation value

Returns:

smoothed image

Return type:

Image instance

Rescale the image. If sfactor> 1 the image is enlarged.

If sfactor < 1 the image is made smaller and smoothing can be applied to reduce sampling artefacts. If sigma is None, use default for scale by sigma=1/sfactor/2. If sigma=0 perform no smoothing.

interpolation

description

'cubic'

bicubic interpolation

'linear'

bilinear interpolation

'area'

resampling using pixel area relation

Example:

>>> from machinevisiontoolbox import Image
>>> img = Image.Read('monalisa.png')
>>> img.scale(2)
Image: 1354 x 1400 (uint8), R:G:B
>>> img.scale(0.5)
Image: 338 x 350 (uint8), R:G:B
References:

  • Robotics, Vision & Control for Python, Section 11.7.2, P. Corke, Springer 2023.

Seealso:

opencv.resize