Contrast enhancement

Image Processing in Python

Rebeca Gonzalez

Data engineer

Contrast enhancement

X-ray image with low contrast

X-ray image with improved contrast

Image Processing in Python

Contrast

Histograms for contrast enhancement

Image Processing in Python

Contrast

Image Processing in Python

Enhance contrast

  • Contrast stretching
  • Histogram equalization
Image Processing in Python

Types

  • Histogram equalization
  • Adaptive histogram equalization
  • Contrast Limited Adaptive Histogram Equalization (CLAHE)

Image Processing in Python

Histogram equalization

Image Processing in Python

Histogram equalization

Image Processing in Python

Histogram equalization

from skimage import exposure


# Obtain the equalized image
image_eq = exposure.equalize_hist(image)


# Show original and result
show_image(image, 'Original')
show_image(image_eq, 'Histogram equalized')
Image Processing in Python

Histogram equalization

Image Processing in Python

Adaptive Equalization

  • Contrastive Limited Adaptive Histogram Equalization

Image Processing in Python

Contrastive Limited Adaptive Equalization

Image Processing in Python

CLAHE in scikit-image

from skimage import exposure

# Apply adaptive Equalization
image_adapteq = exposure.equalize_adapthist(image, clip_limit=0.03)


# Show original and result
show_image(image, 'Original')
show_image(image_adapteq, 'Adaptive equalized')
Image Processing in Python

CLAHE in scikit-image

Image Processing in Python

Let's practice!

Image Processing in Python

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