kornia.color¶

The functions in this section perform various color space conversions.

rgb_to_bgr(image: torch.Tensor) → torch.Tensor[source]¶

Convert a RGB image to BGR.

See RgbToBgr for details.

Parameters: image (torch.Tensor) – RGB Image to be converted to BGR.
Returns: BGR version of the image.
Return type: torch.Tensor

rgb_to_grayscale(input: torch.Tensor) → torch.Tensor[source]¶

Convert a RGB image to grayscale.

See RgbToGrayscale for details.

Parameters: input (torch.Tensor) – RGB image to be converted to grayscale.
Returns: Grayscale version of the image.
Return type: torch.Tensor

rgb_to_hsv(image: torch.Tensor) → torch.Tensor[source]¶

Convert an RGB image to HSV.

Parameters: input (torch.Tensor) – RGB Image to be converted to HSV.
Returns: HSV version of the image.
Return type: torch.Tensor

rgb_to_hls(image: torch.Tensor) → torch.Tensor[source]¶

Convert an RGB image to HLS The image data is assumed to be in the range of (0, 1).

Parameters: input (torch.Tensor) – RGB Image to be converted to HLS.
Returns: HLS version of the image.
Return type: torch.Tensor

rgb_to_luv(image: torch.Tensor, eps: float = 1e-12) → torch.Tensor[source]¶

Converts a RGB image to Luv.

See RgbToLuv for details.

Parameters

image (torch.Tensor) – RGB image
eps (float) – for numerically stability when dividing. Default: 1e-8.

Returns

Luv image

Return type

torch.Tensor

rgb_to_rgba(image: torch.Tensor, alpha_val: Union[float, torch.Tensor]) → torch.Tensor[source]¶

Convert image from RGB to RGBA.

See RgbToRgba for details.

Parameters

image (torch.Tensor) – RGB Image to be converted to RGBA.
alpha_val (float, torch.Tensor) – A float number for the alpha value.

Returns

RGBA version of the image.

Return type

torch.Tensor

rgb_to_xyz(image: torch.Tensor) → torch.Tensor[source]¶

Converts a RGB image to XYZ.

See RgbToXyz for details.

Parameters: image (torch.Tensor) – RGB Image to be converted to XYZ.
Returns: XYZ version of the image.
Return type: torch.Tensor

rgb_to_ycbcr(image: torch.Tensor) → torch.Tensor[source]¶

Convert an RGB image to YCbCr.

Parameters: image (torch.Tensor) – RGB Image to be converted to YCbCr.
Returns: YCbCr version of the image.
Return type: torch.Tensor

rgb_to_yuv(input: torch.Tensor) → torch.Tensor[source]¶

Convert an RGB image to YUV The image data is assumed to be in the range of (0, 1).

Parameters: input (torch.Tensor) – RGB Image to be converted to YUV.
Returns: YUV version of the image.
Return type: torch.Tensor

See RgbToYuv for details.

rgba_to_rgb(image: torch.Tensor) → torch.Tensor[source]¶

Convert image from RGBA to RGB.

See RgbaToRgb for details.

Parameters: image (torch.Tensor) – RGBA Image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

rgba_to_bgr(image: torch.Tensor) → torch.Tensor[source]¶

Convert image from RGBA to BGR.

See RgbaToBgr for details.

Parameters: image (torch.Tensor) – RGBA Image to be converted to BGR.
Returns: BGR version of the image.
Return type: torch.Tensor

bgr_to_grayscale(input: torch.Tensor) → torch.Tensor[source]¶

Convert a BGR image to grayscale.

See BgrToGrayscale for details.

Parameters: input (torch.Tensor) – BGR image to be converted to grayscale.
Returns: Grayscale version of the image.
Return type: torch.Tensor

bgr_to_rgb(image: torch.Tensor) → torch.Tensor[source]¶

Convert a BGR image to RGB.

See BgrToRgb for details.

Parameters: image (torch.Tensor) – BGR Image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

bgr_to_rgba(image: torch.Tensor, alpha_val: Union[float, torch.Tensor]) → torch.Tensor[source]¶

Convert image from BGR to RGBA.

See BgrToRgba for details.

Parameters

image (torch.Tensor) – BGR Image to be converted to RGBA.
alpha_val (float, torch.Tensor) – A float number for the alpha value.

Returns

RGBA version of the image.

Return type

torch.Tensor

hls_to_rgb(image: torch.Tensor) → torch.Tensor[source]¶

Convert an HLS image to RGB The image data is assumed to be in the range of (0, 1).

Parameters: input (torch.Tensor) – HLS Image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

hsv_to_rgb(image: torch.Tensor) → torch.Tensor[source]¶

Convert an HSV image to RGB The image data is assumed to be in the range of (0, 1).

Parameters: input (torch.Tensor) – HSV Image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

luv_to_rgb(image: torch.Tensor, eps: float = 1e-12) → torch.Tensor[source]¶

Converts a Luv image to RGB.

See LuvToRgb for details.

Parameters

image (torch.Tensor) – Luv image
eps (float) – for numerically stability when dividing. Default: 1e-8.

Returns

RGB image

Return type

torch.Tensor

ycbcr_to_rgb(image: torch.Tensor) → torch.Tensor[source]¶

Convert an YCbCr image to RGB The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – YCbCr Image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

yuv_to_rgb(input: torch.Tensor) → torch.Tensor[source]¶

Convert an YUV image to RGB The image data is assumed to be in the range of (0, 1).

Parameters: input (torch.Tensor) – YUV Image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

See YuvToRgb for details.

xyz_to_rgb(image: torch.Tensor) → torch.Tensor[source]¶

Converts a XYZ image to RGB.

See XyzToRgb for details.

Parameters: image (torch.Tensor) – XYZ Image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

Modules¶

class RgbToGrayscale[source]¶

convert RGB image to grayscale version of image.

the image data is assumed to be in the range of (0, 1).

Parameters: input (torch.Tensor) – RGB image to be converted to grayscale.
Returns: grayscale version of the image.
Return type: torch.Tensor

shape:

input: \((*, 3, H, W)\)
output: \((*, 1, H, W)\)

reference:

https://docs.opencv.org/4.0.1/de/d25/imgproc_color_conversions.html

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> gray = kornia.color.RgbToGrayscale()
>>> output = gray(input)  # 2x1x4x5

class BgrToGrayscale[source]¶

convert BGR image to grayscale version of image.

the image data is assumed to be in the range of (0, 1).

Parameters: input (torch.Tensor) – BGR image to be converted to grayscale.
Returns: grayscale version of the image.
Return type: torch.Tensor

shape:

input: \((*, 3, H, W)\)
output: \((*, 1, H, W)\)

reference:

https://docs.opencv.org/4.0.1/de/d25/imgproc_color_conversions.html

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> gray = kornia.color.BgrToGrayscale()
>>> output = gray(input)  # 2x1x4x5

class RgbToHsv[source]¶

Convert image from RGB to HSV.

The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – RGB image to be converted to HSV.
Returns: HSV version of the image.
Return type: torch.tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> hsv = kornia.color.RgbToHsv()
>>> output = hsv(input)  # 2x3x4x5

class HsvToRgb[source]¶

Convert image from HSV to Rgb The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – HSV image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> rgb = kornia.color.HsvToRgb()
>>> output = rgb(input)  # 2x3x4x5

class RgbToHls[source]¶

Convert image from RGB to HLS The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – RGB image to be converted to HLS.
Returns: HLS version of the image.
Return type: torch.tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> hls = kornia.color.RgbToHls()
>>> output = hls(input)  # 2x3x4x5

class HlsToRgb[source]¶

Convert image from HLS to Rgb The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – HLS image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

reference:

https://en.wikipedia.org/wiki/HSL_and_HSV

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> rgb = kornia.color.HlsToRgb()
>>> output = rgb(input)  # 2x3x4x5

class RgbToBgr[source]¶

Convert image from RGB to BGR.

The image data is assumed to be in the range of (0, 1).

Returns: BGR version of the image.
Return type: torch.Tensor

Shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> bgr = kornia.color.RgbToBgr()
>>> output = bgr(input)  # 2x3x4x5

class BgrToRgb[source]¶

Convert image from BGR to RGB.

The image data is assumed to be in the range of (0, 1).

Returns: RGB version of the image.
Return type: torch.Tensor

Shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> rgb = kornia.color.BgrToRgb()
>>> output = rgb(input)  # 2x3x4x5

class RgbToYuv[source]¶

Convert image from RGB to YUV The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – RGB image to be converted to YUV.
Returns: YUV version of the image.
Return type: torch.tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples::

>>> input = torch.rand(2, 3, 4, 5)
>>> yuv = kornia.color.RgbToYuv()
>>> output = yuv(input)  # 2x3x4x5

Reference::

[1] https://es.wikipedia.org/wiki/YUV#RGB_a_Y’UV

class YuvToRgb[source]¶

Convert image from YUV to RGB The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – YUV image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples::

>>> input = torch.rand(2, 3, 4, 5)
>>> rgb = kornia.color.YuvToRgb()
>>> output = rgb(input)  # 2x3x4x5

class RgbToRgba(alpha_val: Union[float, torch.Tensor])[source]¶

Convert image from RGB to RGBA.

Add an alpha channel to existing RGB image.

Parameters: alpha_val (float, torch.Tensor) – A float number for the alpha value.
Returns: RGBA version of the image.
Return type: torch.Tensor

Shape:

image: \((*, 3, H, W)\)
output: \((*, 4, H, W)\)

Examples:

>>> input = torch.rand(2, 3, 4, 5)
>>> rgba = kornia.color.RgbToRgba(1.)
>>> output = rgba(input)  # 2x4x4x5

class BgrToRgba(alpha_val: Union[float, torch.Tensor])[source]¶

Convert image from BGR to RGBA.

Add an alpha channel to existing BGR image.

Parameters: alpha_val (float, torch.Tensor) – A float number for the alpha value.
Returns: RGBA version of the image.
Return type: torch.Tensor

Shape:

image: \((*, 3, H, W)\)
output: \((*, 4, H, W)\)

Examples:

>>> input = torch.rand(2, 3, 4, 5)
>>> rgba = kornia.color.BgrToRgba(1.)
>>> output = rgba(input)  # 2x4x4x5

class RgbaToRgb[source]¶

Convert image from RGBA to RGB.

Remove an alpha channel from RGB image.

Returns: RGB version of the image.
Return type: torch.Tensor

shape:

image: \((*, 4, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> input = torch.rand(2, 4, 4, 5)
>>> rgba = kornia.color.RgbaToRgb()
>>> output = rgba(input)  # 2x3x4x5

class RgbaToBgr[source]¶

Convert image from RGBA to BGR.

Remove an alpha channel from BGR image.

Returns: BGR version of the image.
Return type: torch.Tensor

shape:

image: \((*, 4, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> input = torch.rand(2, 4, 4, 5)
>>> rgba = kornia.color.RgbaToBgr()
>>> output = rgba(input)  # 2x3x4x5

class RgbToXyz[source]¶

Converts an image from RGB to XYZ

The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – RGB image to be converted to XYZ.
Returns: XYZ version of the image.
Return type: torch.Tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples

>>> input = torch.rand(2, 3, 4, 5)
>>> xyz = kornia.color.RgbToXyz()
>>> output = xyz(input)  # 2x3x4x5

Reference:: [1] https://docs.opencv.org/4.0.1/de/d25/imgproc_color_conversions.html

class XyzToRgb[source]¶

Converts an image from XYZ to RGB

Parameters: image (torch.Tensor) – XYZ image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples

>>> input = torch.rand(2, 3, 4, 5)
>>> rgb = kornia.color.XyzToRgb()
>>> output = rgb(input)  # 2x3x4x5

Reference:: [1] https://docs.opencv.org/4.0.1/de/d25/imgproc_color_conversions.html

class RgbToLuv[source]¶

Converts an image from RGB to Luv

The image data is assumed to be in the range of \([0, 1]\). Luv color is computed using the D65 illuminant and Observer 2.

Parameters: image (torch.Tensor) – RGB image to be converted to Luv.
Returns: Luv version of the image.
Return type: torch.Tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples

>>> input = torch.rand(2, 3, 4, 5)
>>> luv = kornia.color.RgbToLuv()
>>> output = luv(input)  # 2x3x4x5

Reference:

[1] https://docs.opencv.org/4.0.1/de/d25/imgproc_color_conversions.html

[2] https://www.easyrgb.com/en/math.php

[3] http://www.poynton.com/ColorFAQ.html

class LuvToRgb[source]¶

Converts an image from Luv to RGB

Parameters: image (torch.Tensor) – Luv image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.Tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples

>>> input = torch.rand(2, 3, 4, 5)
>>> rgb = kornia.color.LuvToRgb()
>>> output = rgb(input)  # 2x3x4x5

References

[1] https://docs.opencv.org/4.0.1/de/d25/imgproc_color_conversions.html

[2] https://www.easyrgb.com/en/math.php

[3] http://www.poynton.com/ColorFAQ.html

class YcbcrToRgb[source]¶

Convert image from YCbCr to Rgb The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – YCbCr image to be converted to RGB.
Returns: RGB version of the image.
Return type: torch.tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> rgb = kornia.color.YcbcrToRgb()
>>> output = rgb(input)  # 2x3x4x5

class RgbToYcbcr[source]¶

Convert image from RGB to YCbCr The image data is assumed to be in the range of (0, 1).

Parameters: image (torch.Tensor) – RGB image to be converted to YCbCr.
Returns: YCbCr version of the image.
Return type: torch.tensor

shape:

image: \((*, 3, H, W)\)
output: \((*, 3, H, W)\)

Examples:

>>> import torch
>>> import kornia
>>> input = torch.rand(2, 3, 4, 5)
>>> ycbcr = kornia.color.RgbToYcbcr()
>>> output = ycbcr(input)  # 2x3x4x5