Scikit Image - Multi Images

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Multi Image or Multi-frame Image, in general, refers to an image format that can store and represent multiple images or frames within a single file. For instance, animated GIFs and multi-frame TIFF files are examples of multi-image formats.

MultiImage class in Scikit Image

The MultiImage class in the scikit-image io module is used to specifically handle multiframe TIFF images. It provides a convenient way to load and manipulate multi-frame TIFF images.

When working with multi-frame TIFFs using the MultiImage class, it returns a list of image-data arrays, similar to the ImageCollection class. However, there is a difference in how they handle multi-frame images. Multi-Image stores all frames of a multi-frame TIFF image as a single element in the list, with a shape of (N, W, H), where N is the number of frames and W and H are the width and height of each frame.

Following is the syntax of this class −

class skimage.io.MultiImage(filename, conserve_memory=True, dtype=None,
**imread_kwargs)

Here are the parameters of the class −

• filename − A string or list of strings specifying the pattern or filenames to load. The path can be absolute or relative.
• conserve_memory (optional) − A boolean value. If set to True, only one image will be kept in memory at a time. If set to False, images will be cached after loading to improve subsequent access speed.

Example 1

The following example demonstrates how to use the MultiImage class to load a multiframe TIFF image and obtain information about the loaded image.

from skimage.io import MultiImage

# Load the multi-frame TIFF image
multi_image = MultiImage('Images_/Multi_Frame.tif')

# Access and display information about the loaded image file
print(multi_image)
print('Type:',type(multi_image))
print('Length:',len(multi_image))
print('Shape:',multi_image[0].shape)

Output

['Images_/Multi_Frame.tif']
Type: < class 'skimage.io.collection.MultiImage' >
Length: 1
Shape: (6, 382, 363, 3)

Example 2

Let's read the same Multi-frame TIFF file, "Multi_Frame.tif" using the ImageCollection class and observe how it treats the multi-frame images compared to the MultiImage class.

from skimage.io import ImageCollection

# Load the multi-frame TIFF image
ic = ImageCollection('Images_/Multi_Frame.tif')

# Access and display information about the loaded image file
print(ic)
print('Type:',type(ic))
print('Length:',len(ic))
print('Shape:',ic[0].shape)

Output

['Images_/Multi_Frame.tif']
Type: < class 'skimage.io.collection.ImageCollection' >
Length: 6
Shape: (382, 363, 3)

When working with an animated GIF image, MultiImage reads only the first frame, whereas the ImageCollection reads all frames by default.

Example 3

Let's look into the following example and observe how the MultiImage class treats the animated GIF image.

from skimage.io import MultiImage

# Load an animated GIF image
multi_image = MultiImage('Images/dance-cartoon.gif')

# display the multi_image object
print(multi_image)
print('Type:',type(multi_image))
print('Length:',len(multi_image))
for i, frame in enumerate(multi_image):
   print('Image {} shape:{}'.format(i, frame.shape))

Output

['Images/dance-cartoon.gif']
Type: < class 'skimage.io.collection.MultiImage'>
Length: 1
Image 0 shape:(300, 370, 4)

Example 4

Let's read the same GIF file, "dance-cartoon.gif" using the ImageCollection class and observe how it treats the animated GIF image compared to the MultiImage class.

from skimage.io import ImageCollection

# Load an animated GIF image
ic = ImageCollection('Images/dance-cartoon.gif')

# Access and display information about the loaded image file
print(ic)
print('Type:',type(ic))
print('Length:',len(ic))
for i, frame in enumerate(ic):
   print('Image {} shape:{}'.format(i, frame.shape))

Input Image

Output

['Images/dance-cartoon.gif']
Type: <class 'skimage.io.collection.ImageCollection'>
Length: 12
Image 0 shape:(300, 370, 4)
Image 1 shape:(300, 370, 4)
Image 2 shape:(300, 370, 4)
Image 3 shape:(300, 370, 4)
Image 4 shape:(300, 370, 4)
Image 5 shape:(300, 370, 4)
Image 6 shape:(300, 370, 4)
Image 7 shape:(300, 370, 4)
Image 8 shape:(300, 370, 4)
Image 9 shape:(300, 370, 4)
Image 10 shape:(300, 370, 4)
Image 11 shape:(300, 370, 4)