假设你想要一张灰度图像:

im = Image.new('L', (width, height))
im.putdata(an_array.flatten().tolist())
im.save("image.tiff")

你可以在Python中使用'skimage'库

例子:

from skimage.io import imsave
imsave('Path_to_your_folder/File_name.jpg',your_array)

一个答案使用PIL(只是在情况下它是有用的)。

给定一个numpy数组" a ":

from PIL import Image
im = Image.fromarray(A)
im.save("your_file.jpeg")

你可以用几乎任何你想要的格式替换“jpeg”。更多关于格式的细节请点击这里

@ideasman42回答的附录:

def saveAsPNG(array, filename):
    import struct
    if any([len(row) != len(array[0]) for row in array]):
        raise ValueError, "Array should have elements of equal size"

                                #First row becomes top row of image.
    flat = []; map(flat.extend, reversed(array))
                                 #Big-endian, unsigned 32-byte integer.
    buf = b''.join([struct.pack('>I', ((0xffFFff & i32)<<8)|(i32>>24) )
                    for i32 in flat])   #Rotate from ARGB to RGBA.

    data = write_png(buf, len(array[0]), len(array))
    f = open(filename, 'wb')
    f.write(data)
    f.close()

所以你可以这样做:

saveAsPNG([[0xffFF0000, 0xffFFFF00],
           [0xff00aa77, 0xff333333]], 'test_grid.png')

生产test_grid.png:

(透明性也可以通过减少0xff的高字节来工作。)

纯Python(2 & 3)，一个没有第三方依赖的代码片段。

这个函数写入压缩的真彩色(每像素4字节)RGBA PNG。

def write_png(buf, width, height):
    """ buf: must be bytes or a bytearray in Python3.x,
        a regular string in Python2.x.
    """
    import zlib, struct

    # reverse the vertical line order and add null bytes at the start
    width_byte_4 = width * 4
    raw_data = b''.join(
        b'\x00' + buf[span:span + width_byte_4]
        for span in range((height - 1) * width_byte_4, -1, - width_byte_4)
    )

    def png_pack(png_tag, data):
        chunk_head = png_tag + data
        return (struct.pack("!I", len(data)) +
                chunk_head +
                struct.pack("!I", 0xFFFFFFFF & zlib.crc32(chunk_head)))

    return b''.join([
        b'\x89PNG\r\n\x1a\n',
        png_pack(b'IHDR', struct.pack("!2I5B", width, height, 8, 6, 0, 0, 0)),
        png_pack(b'IDAT', zlib.compress(raw_data, 9)),
        png_pack(b'IEND', b'')])

．.． 数据应该直接写入以二进制文件打开的文件中，如:

data = write_png(buf, 64, 64)
with open("my_image.png", 'wb') as fh:
    fh.write(data)

原始来源 参见:Rust Port来自这个问题。 感谢@Evgeni Sergeev的示例用法:https://stackoverflow.com/a/21034111/432509

matplotlib:

import matplotlib.image

matplotlib.image.imsave('name.png', array)

适用于matplotlib 1.3.1，我不知道低版本。从文档字符串:

Arguments:
  *fname*:
    A string containing a path to a filename, or a Python file-like object.
    If *format* is *None* and *fname* is a string, the output
    format is deduced from the extension of the filename.
  *arr*:
    An MxN (luminance), MxNx3 (RGB) or MxNx4 (RGBA) array.