skimage图像的读取与保存

╰半橙微兮° 2021-11-23 02:22 671阅读 0赞

首先,说明用opencv与skimage.io.imread读取和保存图片的区别:

读取和保存后的都是numpy格式，但cv2的读取和存储格式是BGR，而skimage的读取和存储格式是RGB。

1.读取图片:

#skimage读取图片
    img=skimage.io.imread(file_dir, as_grey=False)
    
    #imread读取图片,0:grey,1:color,默认:color
    img=cv2.imread(file_dir,1)

image.io.imread用法:

`image.io.``imread`(*fname*, *as\_gray=False*, *plugin=None*, *\*\*plugin\_args*)[\[source\]][source]

Load an image from file.

Parameters

**fname**string

Image file name, e.g. `test.jpg` or URL.

**as\_gray**bool, optional

If True, convert color images to gray-scale (64-bit floats). Images that are already in gray-scale format are not converted.

**plugin**str, optional

Name of plugin to use. By default, the different plugins are tried (starting with imageio) until a suitable candidate is found. If not given and fname is a tiff file, the tifffile plugin will be used.

Returns

**img\_array**ndarray

The different color bands/channels are stored in the third dimension, such that a gray-image is MxN, an RGB-image MxNx3 and an RGBA-image MxNx4.

Other Parameters

**plugin\_args**keywords

Passed to the given plugin.

2.存储图片

#skimge
    skimage.io.imsave(file_dir, img)
    
    #存储的时候保存为unit8格式
    img=np.array(img,dtype=np.uint8)
    
    #cv2
    cv2.imwrite(file_dir,img)

注意:如果float类型用imsave()保存，需要数值在-1到1之间，否则会报错.如果一开始就是uint8，保存的时候就无需除以255，如：

img=np.array(img,dtype=np.uint8)

3.将像素值转换为\[0,1\]之间的数值.也就是给每一个像素值除以255.

img\_as\_float32

Convert an image to single-precision (32-bit) floating point format, with values in \[0, 1\].

skimage.img_as_float(skimage.io.imread(filename, as_grey=not color))

[source]: https://github.com/scikit-image/scikit-image/blob/master/skimage/io/_io.py#L14