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python中原始图像的jpeg解压

rawimage python-imageio compression jpeg python

Ian Rehwinkel · 技术社区 · 6 年前

当我尝试对原始数据进行jpeg解压缩(老式的jpeg压缩,不是jpeg-ls,也不是jpeg2000)时,我得到以下错误:

Traceback (most recent call last):
  File "raw-reader.py", line 766, in <module>
    raw_image_data = imageio.imread(io.BytesIO(raw_packed_image_data))
  File "/home/ian/.local/lib/python3.6/site-packages/imageio/core/functions.py", line 206, in imread
    reader = read(uri, format, 'i', **kwargs)
  File "/home/ian/.local/lib/python3.6/site-packages/imageio/core/functions.py", line 129, in get_reader
    return format.get_reader(request)
  File "/home/ian/.local/lib/python3.6/site-packages/imageio/core/format.py", line 168, in get_reader
    return self.Reader(self, request)
  File "/home/ian/.local/lib/python3.6/site-packages/imageio/core/format.py", line 217, in __init__
    self._open(**self.request.kwargs.copy())
  File "/home/ian/.local/lib/python3.6/site-packages/imageio/plugins/pillow.py", line 398, in _open
    pilmode=pilmode, as_gray=as_gray)
  File "/home/ian/.local/lib/python3.6/site-packages/imageio/plugins/pillow.py", line 122, in _open
    self._im = factory(self._fp, '')
  File "/home/ian/.local/lib/python3.6/site-packages/PIL/JpegImagePlugin.py", line 780, in jpeg_factory
    im = JpegImageFile(fp, filename)
  File "/home/ian/.local/lib/python3.6/site-packages/PIL/ImageFile.py", line 102, in __init__
    self._open()
  File "/home/ian/.local/lib/python3.6/site-packages/PIL/JpegImagePlugin.py", line 339, in _open
    handler(self, i)
  File "/home/ian/.local/lib/python3.6/site-packages/PIL/JpegImagePlugin.py", line 166, in SOF
    raise SyntaxError("cannot handle %d-bit layers" % self.bits)
SyntaxError: cannot handle 14-bit layers

图像中的原始数据是14位jpeg数据,ImageIO无法读取。当我尝试使用枕头时,它甚至没有识别出数据是jpeg。我现在的问题是:如何在不编写自己的jpeg解压器的情况下解压数据,同时记住数据是14位的?

我的代码:

import io
import imageio

allbytes = open("raw_data.dat", "rb").read()

raw_packed_image_data = allbytes
raw_image_data = imageio.imread(io.BytesIO(raw_packed_image_data))

文件 raw_data.dat 是一个纯包含用jpeg压缩的原始图像数据的文件。链接到 raw_data.dat

2 回复 | 直到 6 年前

cgohlke 6 年前

raw_data.dat 是一个 JPEG Lossless, Nonhierarchical 文件具有2帧和8位精度,这是一种非常罕见的格式。

这个 imagecodecs 包可以读取文件(假定 _imagecodecs 存在Cython扩展):

>>> from imagecodecs import jpegsof3_decode
>>> data = open('raw_data.dat', 'rb').read()
>>> image = jpegsof3_decode(data)
>>> image.shape
(3528, 2640, 2)
>>> image.dtype
dtype('uint16')

leadtools sdk还应该能够读取文件(未测试)。

sophros 6 年前

我相信这个问题可以通过使用不同的库来加载图像来解决。类似的潜在问题已在此处发布 How to combine 3 high range JPEG2000 images into single RGB one? . 您可以沿着这些线使用某些内容:

import matplotlib.image as mpimg
img_red = mpimg.imread('raw_data.dat')

然后,您可以使用读取位图进行进一步的操作,就好像它是通过pil/bellow/imageio加载的一样。