I have a problem converting a tiff image from a microscope to a jpeg, which should be shown within a web application.
I tried the following:
image = Image.open(file_name)
image.convert(mode="RGB")
image.save('my.jpeg')
>>IOError: cannot write mode I;16 as JPEG
Anybody has some experience in converting 16-bit TIFF files to jpegs...
I have linked such a file below.
Thanks for your help!
https://drive.google.com/open?id=0B04N02JqhWJOWjBPY1RRZkIwbTg
It's a bug. Here is a workaround:
import Image
image = Image.open("Fredy1_002.tif")
image.mode = 'I'
image.point(lambda i:i*(1./256)).convert('L').save('my.jpeg')
See https://stackoverflow.com/a/7248480/839338
Related
I have an image in memory (downloaded from an online source) and I want to convert it to a different format before sending it on to a different online location.
The conversion is .webp to .jpg but that's not really relevant.
With Pillow I can easily convert local images and save them back to disc, but I can't get it to work with an image in memory.
I don't necessarily need to use Pillow. Any way to convert the image without having to save anything to disc is fine.
I am new to BytesIO with PIL, so just check my code attempt, with my test image it works, let me know
from PIL import Image
from io import BytesIO
img = Image.open('test.webp')
print('image : ', img.format)
img.show()
# Write PIL Image to in-memory PNG
membuf = BytesIO()
img.save(membuf, format="png")
img = Image.open(membuf)
print('image : ', img.format)
img.show()
I have multispectral images with the .tif extension. How can I read such multispectral images with Python?
Pillow module supports "Multi-frame TIFF Images" that might be your thing.
Could you provide an example file you would like to open and, what do you expect inside?
https://pillow.readthedocs.io/en/stable/handbook/image-file-formats.html#reading-multi-frame-tiff-images
This might do the job:
from PIL import Image
im = Image.open("image.tif")
print(im.num_frames)
im.seek(im.tell() + 1))
I am using tinytags module in python to get the cover art of a mp3 file and want to display or store it. The return type of the variable is showing to be bytes. I have tried fumbling around with PIL using frombytes but to no avail. Is there any method to convert the bytes to image?
from tinytag import TinyTag
tag = TinyTag.get("03. Me, Myself & I.mp3", image=True)
img = tag.get_image()
I actually got a PNG image when I called tag.get_image() but I guess you might get a JPEG. Either way, you can wrap it in a BytesIO and open it with PIL/Pillow or display it. Carrying on from your code:
from PIL import Image
import io
...
im = tag.get_image()
# Make a PIL Image
pi = Image.open(io.BytesIO(im))
# Save as PNG, or JPEG
pi.save('cover.png')
# Display
pi.show()
Note that you don't have to use PIL/Pillow. You could look at the first few bytes and if they are a PNG signature (\x89PNG) save data as binary with PNG extension. If the signature is JPEG (\xff \xd8) save data as binary with JPEG extension.
Given the short, 5 page PDF file (attached at the bottom), and the following python code to convert to a multi-page TIFF:
from wand.image import Image
with Image(filename='5-page-pdf.pdf', resolution=200) as img:
img.type = "grayscale"
img.format = "tiff"
img.compression = "lzw"
img.save(filename="test.tiff")
results in a TIFF file that has pages 2-4 as what appears to be black text on a dark-grey (or maybe transparent) background. Other image processing libraries cannot open the file or render it.
Converting the same PDF with ImageMagick, which Wand uses, works just fine
convert -density 200 5-page-pdf.pdf -type grayscale -compress lzw 5-page-pdf.tiff
this produces a file that does work with other imaging libraries and looks correct in a TIFF viewer.
I've tried removing the alpha channel, I've tried setting the background color to 'White', and a few other things, to no avail. The TIFF that comes out of Wand is always garbled. If it's doable in ImageMagick it should be doable in Wand, right? What parameter or setting am I missing?
Original PDF
Wand Produced TIFF
Looks like setting the img.alpha_channel property is not propagating across the pages.
Try this workaround
from wand.api import library
from wand.image import Image
with Image(filename="5-page-pdf.pdf", resolution=200) as img:
img.type = 'grayscale'
img.compression = "lzw"
# Manually iterate over all page, and turn off alpha channel.
library.MagickResetIterator(img.wand)
for idx in range(library.MagickGetNumberImages(img.wand)):
library.MagickSetIteratorIndex(img.wand, idx)
img.alpha_channel = 'off'
img.save(filename="test.tiff")
I'm new to image processing. I just wanted to get a tiff image from raw format(NEF). I used rawpy module to get the desired output, yet the tiff image is RGB with 4 channels. I couldn't know why there is a fourth channel in the new image?
Can anyone please explain to me what is going on, and how I can get tiff image with three RGB channels?
import rawpy
import matplotlib.pylab as plt
raw_image = "DSC_0001.NEF"
raw = rawpy.imread(raw_image)
rgb = raw.postprocess()
plt.imsave("new.tiff", rgb )
image = plt.imread("new.tiff")
print(image.shape)
The array shape is : (2868, 4310, 4) !
Finally I found the reason:
plt.imsave saves the image in RGBA , while I can use skim age.io.imsave and it will save it as RGB.
Source: Github Issue entry