【发布时间】：2017-03-18 06:40:04
【问题描述】：
使用我的 NIKON D5100 拍照时，我会以 raw (.NEF) 和 jpeg 格式进行拍摄。大多数时候我不使用原始图像，但有时我会使用。
为了简化图像的标记和选择，我想自动将原始图像移动到不同的位置。作为检查 python 脚本以移动原始图像，我想将 jpeg 的图像分辨率与原始分辨率进行比较。到目前为止，我还没有找到一种方法可以为 raw 和 jpeg 图像返回相同的大小。
这是我使用 Python 尝试过的方法的总结：
from PIL import Image as PIL_Image
from wand.image import Image as wand_Image
import imageio
from PIL.ExifTags import TAGS
import exifread
from collections import namedtuple
def get_exif(fname):
# http://www.blog.pythonlibrary.org/2010/03/28/getting-photo-metadata-exif-using-python/
ret = {}
i = PIL_Image.open(fname)
info = i._getexif()
for tag, value in info.items():
decoded = TAGS.get(tag, tag)
ret[decoded] = value
return ret
def get_imagesize_PIL(fname):
with PIL_Image.open(fname) as im:
return im.size
def get_imagesize_PIL2(fname):
exif = get_exif(fname)
return exif['ExifImageHeight'], exif['ExifImageWidth']
def get_imagesize_PIL3(fname):
with PIL_Image.open(fname) as im:
return im.info
def get_imagesize_imageioraw(fname):
return imageio.imread(fname, "raw").shape[:-1]
def get_imagesize_imageio(fname):
return imageio.imread(fname).shape[:-1]
def get_imagesize_exifread(fname): # http://stackoverflow.com/a/18027454/1562285
exif = exifread.process_file(open(fname, 'rb'), strict=True)
return exif['Image XResolution'], exif['Image YResolution']
def get_imagesize_exifread2(fname):
exif = exifread.process_file(open(fname, 'rb'), strict=True)
return exif['Image ImageLength'], exif['Image ImageWidth']
def get_imagesize_exifread3(fname):
exif = exifread.process_file(open(fname, 'rb'), strict=True)
return exif['MakerNote CropHiSpeed']
def get_imagesize_exifread4(fname):
exif = exifread.process_file(open(fname, 'rb'), strict=True)
return exif['EXIF ExifImageLength'], exif['EXIF ExifImageWidth']
def get_imagesize_wand(fname):
with wand_Image(filename=fname) as img:
return img.size
def get_imagesize_wand2(fname):
with wand_Image(filename=fname) as img:
return img.page
# def get_imagesize_wand3(fname):
# with wand_Image(filename=fname) as img:
# return img.info
def get_imagesize_libraw(fname):
with rawkit_Raw(filename=fname) as raw:
print(raw.Metadata.height, raw.Metadata.width)
def create_eval(fmethod, fname):
try:
eval_str = "get_imagesize_%s('%s')" % (fmethod, fname)
# print(eval_str)
return eval(eval_str)
except BaseException as e:
return str(e)
if __name__ == '__main__':
file_nt = namedtuple("image_file", "filename tag")
filetypes = list()
filetypes.append(file_nt("20120917_131155 DSC_0159.JPG", "jpeg"))
filetypes.append(file_nt("20120917_131155 DSC_0159.NEF", "nef"))
# filetypes.append(file_nt("20120917_131155 DSC_0159.xmp", "xmp"))
# @TODO: add method to check into xmp?
methods = [
"PIL",
"PIL2",
"PIL3",
"imageioraw",
"imageio",
"exifread",
"exifread2",
"exifread3",
"exifread4",
"wand",
"wand2",
"libraw",
]
for method in methods:
for filetype in filetypes:
print("%s %s: %s" % (filetype.tag, method, repr(create_eval(method, filetype.filename))))
# @TODO: add timers to check the fastest method
有了这个结果
jpeg PIL: (4928, 3264)
nef PIL: (160, 120)
jpeg PIL2: (3264, 4928)
nef PIL2: "'TiffImageFile' object has no attribute '_getexif'"
jpeg PIL3: {'exif': b'Exif\x00\x00MM\x00*\x00\x00\x00\x08\x00\x0b\x01\x0f\x00\x02\x00\x00\x00\x12\x00\x00\x00\x94\x01\x10\x00\x02\x00\x00\x00\x0c\x00\x00\x00\xa8\x01\x12\x00...'}
nef PIL3: {'compression': 'raw', 'dpi': (300.0, 300.0)}
jpeg imageioraw: 'Could not load bitmap "C:\\Users\\maarten\\PycharmProjects\\fotosize\\20120917_131155 DSC_0159.JPG": LibRaw : failed to open input stream (unknown format)'
nef imageioraw: (3280, 4948)
jpeg imageio: (3264, 4928)
nef imageio: (120, 160)
jpeg exifread: ((0x011A) Ratio=300 @ 180, (0x011B) Ratio=300 @ 188)
nef exifread: ((0x011A) Ratio=300 @ 356, (0x011B) Ratio=300 @ 364)
jpeg exifread2: "'Image ImageLength'"
nef exifread2: ((0x0101) Long=120 @ 42, (0x0100) Long=160 @ 30)
jpeg exifread3: (0x001B) Short=[0, 4992, 3280, 4992, 3280, 0, 0] @ 1676
nef exifread3: (0x001B) Short=[0, 4992, 3280, 4992, 3280, 0, 0] @ 1852
jpeg exifread4: ((0xA003) Short=3264 @ 526, (0xA002) Short=4928 @ 514)
nef exifread4: "'EXIF ExifImageLength'"
jpeg wand: (4928, 3264)
nef wand: (4948, 3280)
jpeg wand2: (4928, 3264, 0, 0)
nef wand2: (4948, 3280, 0, 0)
jpeg libraw: 'Cannot find LibRaw on your system!'
nef libraw: 'Cannot find LibRaw on your system!'
返回 160x120 的可能是嵌入的预览图像
Windows 资源管理器似乎确实找到了正确的尺寸 screenshot
我也尝试过 rawkit，但它似乎没有找到 libraw。我没有找到关于如何“安装”libraw 的明确说明，但我尝试将其命名为 libraw.dll 或 Raw.dll 复制到“C:\Anaconda3\Library\bin”中，当我尝试时
In[3]: ctypes.util.find_library("libraw")
Out[3]:
'C:\\Anaconda3\\Library\\bin\\libraw.dll'
In[4]: ctypes.util.find_library("Raw")
Out[4]:
'C:\\Anaconda3\\Library\\bin\\Raw.dll'
它似乎找到了它。
有人知道我可以使用什么方法吗？对于 jpeg 和 NEF 图像，它不必是相同的方法，但这是受欢迎的。
目前性能不是关键问题，但越快越好
代码和示例图片可以在my github repo找到
【问题讨论】：
标签： python image python-3.x image-size