Blurring a part of an image in Python¶
This very short notebook shows how to open an image (eg a PNG image), and nicely blur a part of it.
In [1]:
import numpy as np
import skimage
In [2]:
%load_ext watermark
%watermark -v -m -a "Lilian Besson (Naereen)" -p numpy,skimage -g
Lilian Besson (Naereen) CPython 3.6.3 IPython 6.2.1 numpy 1.14.0 skimage 0.13.1 compiler : GCC 7.2.0 system : Linux release : 4.13.0-25-generic machine : x86_64 processor : x86_64 CPU cores : 4 interpreter: 64bit Git hash : 334c698a8a98e845aad210b3a434b0e346ecb551
Blur all the image¶
Let's import one of the example image, and blur all of it using skimage.filters.gaussian.
In [9]:
from skimage import data, io, filters
image = data.astronaut()
In [10]:
def imshow(image):
io.imshow(image)
io.show()
In [11]:
imshow(image)
/usr/local/lib/python3.6/dist-packages/skimage/io/_plugins/matplotlib_plugin.py:51: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`. out_of_range_float = (np.issubdtype(image.dtype, np.float) and
In [5]:
from skimage.filters import gaussian
In [12]:
filtered_img = gaussian(image, sigma=1, multichannel=True)
imshow(filtered_img)
/usr/local/lib/python3.6/dist-packages/skimage/io/_plugins/matplotlib_plugin.py:51: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`. out_of_range_float = (np.issubdtype(image.dtype, np.float) and
In [13]:
filtered_img = gaussian(image, sigma=2, multichannel=True)
imshow(filtered_img)
/usr/local/lib/python3.6/dist-packages/skimage/io/_plugins/matplotlib_plugin.py:51: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`. out_of_range_float = (np.issubdtype(image.dtype, np.float) and
Blur only an area of the image¶
In [17]:
image.shape
Out[17]:
(512, 512, 3)
In [71]:
def blur(image, x0, x1, y0, y1, sigma=1, imshowall=False):
x0, x1 = min(x0, x1), max(x0, x1)
y0, y1 = min(y0, y1), max(y0, y1)
im = image.copy()
sub_im = im[x0:x1,y0:y1].copy()
if imshowall: imshow(sub_im)
blur_sub_im = gaussian(sub_im, sigma=sigma)
if imshowall: imshow(blur_sub_im)
blur_sub_im = np.round(255 * blur_sub_im)
im[x0:x1,y0:y1] = blur_sub_im
return im
In [72]:
filtered_img = blur(image, 80, 180, 170, 270, sigma=1)
imshow(filtered_img)
/usr/local/lib/python3.6/dist-packages/skimage/filters/_gaussian.py:108: RuntimeWarning: Images with dimensions (M, N, 3) are interpreted as 2D+RGB by default. Use `multichannel=False` to interpret as 3D image with last dimension of length 3. warn(RuntimeWarning(msg)) /usr/local/lib/python3.6/dist-packages/skimage/io/_plugins/matplotlib_plugin.py:51: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`. out_of_range_float = (np.issubdtype(image.dtype, np.float) and
In [76]:
filtered_img = blur(image, 80, 180, 170, 270, sigma=5)
imshow(filtered_img)
/usr/local/lib/python3.6/dist-packages/skimage/filters/_gaussian.py:108: RuntimeWarning: Images with dimensions (M, N, 3) are interpreted as 2D+RGB by default. Use `multichannel=False` to interpret as 3D image with last dimension of length 3. warn(RuntimeWarning(msg)) /usr/local/lib/python3.6/dist-packages/skimage/io/_plugins/matplotlib_plugin.py:51: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`. out_of_range_float = (np.issubdtype(image.dtype, np.float) and
In [73]:
filtered_img = blur(image, 80, 180, 170, 270, sigma=10)
imshow(filtered_img)
/usr/local/lib/python3.6/dist-packages/skimage/filters/_gaussian.py:108: RuntimeWarning: Images with dimensions (M, N, 3) are interpreted as 2D+RGB by default. Use `multichannel=False` to interpret as 3D image with last dimension of length 3. warn(RuntimeWarning(msg)) /usr/local/lib/python3.6/dist-packages/skimage/io/_plugins/matplotlib_plugin.py:51: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`. out_of_range_float = (np.issubdtype(image.dtype, np.float) and
In [74]:
filtered_img = blur(image, 80, 180, 170, 270, sigma=20)
imshow(filtered_img)
/usr/local/lib/python3.6/dist-packages/skimage/filters/_gaussian.py:108: RuntimeWarning: Images with dimensions (M, N, 3) are interpreted as 2D+RGB by default. Use `multichannel=False` to interpret as 3D image with last dimension of length 3. warn(RuntimeWarning(msg)) /usr/local/lib/python3.6/dist-packages/skimage/io/_plugins/matplotlib_plugin.py:51: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`. out_of_range_float = (np.issubdtype(image.dtype, np.float) and
Conclusion¶
That's it.