If I have multiple base64 strings that are images (one string = one image). Is there a way to combine them and decode to a single image file? i.e. from multiple base64 strings, merge and output a single image file.
I'm not sure how I would approach this using Pillow (or if I even need it).
Further clarification:
The source images are TIFFs that are encoded into base64
When I say "merge", I mean turning multiple images into a multi-page image like you see in a multi-page PDF
I dug through the Pillow documentation (v5.3) and found something that seems to work. Basically, there are two phases to this:
Save encoded base64 strings as TIF
Append them together and save to disk
Example using Python 3.7:
from PIL import Image
import io
import base64
base64_images = ["asdfasdg...", "asdfsdafas..."]
image_files = []
for base64_string in base64_images:
buffer = io.BytesIO(base64.b64decode(base64_string))
image_file = Image.open(buffer)
image_files.append(image_file)
combined_image = images_files[0].save(
'output.tiff',
save_all=True,
append_images=image_files[1:]
)
In the above code, I first create PIL Image objects from a bytes buffers in order to do this whole thing in-memory but you can probably use .save() and create a bunch of tempfiles instead if I/O isn't a concern.
Once I have all the PIL Image objects, I choose the first image (assuming they were in desired order in base64_images list) and append the rest of the images with append_images flag. The resulting image has all the frames in one output file.
I assume this pattern is extensible to any image format that supports the save_all and append_images keyword arguments. The Pillow documentation should let you know if it is supported.
Related
I need to save an Image in Python (created as a Numpy array) as a JPEG file, while including a "comment" in the file with some specific metadata. This metadata will be used by another (third-party) application and is a simple ASCII string. I have a sample image including such a "comment", which I can read out using Pillow (PIL), via the image.info['comment'] or the image.app['COM'] property. However, when I try a simple round-trip, i.e. loading my sample image and save it again using a different file name, the comment is no longer preserved. Equally, I found no way to include a comment in a newly created image.
I am aware that EXIF tags are the preferred way to save metadata in JPEG images, but as mentioned, the third-party application only accepts this data as a "comment", not as EXIF, which I cannot change. After reading this question, I looked into the binary structure of my sample file and found the comment at the start of the file, after a few bytes of some other (meta)data. I do however not know a lot about binary file manipulation, and also I was wondering if there is a more elegant way, other than messing with the binary...
EDIT: minimum example:
from PIL import Image
img = Image.open(path) # where path is the path to the sample image
# this prints the desired metadata if it is correctly saved in loaded image
print(img.info["comment"])
img.save(new_path) # save with different file name
img.close()
# now open to see if it has been saved correctly
new_img = Image.open(new_path)
print(new_img.info['comment']) # now results in KeyError
I also tried img.save(new_path, info=img.info), but this does not seem to have an effect. Since img.info['comment'] appears identical to img.app['COM'], I tried img.save(new_path, app=img.app), again does not work.
Just been having a play with this and I couldn't see anything directly in Pillow to support this. I've found that the save() method supports a parameter called extra that can be used to pass arbitrary bytes to the output file.
We then just need a simple method to turn a comment into a valid JPEG segment, for example:
import struct
from PIL import Image
def make_jpeg_variable_segment(marker: int, payload: bytes) -> bytes:
"make a JPEG segment from the given payload"
return struct.pack('>HH', marker, 2 + len(payload)) + payload
def make_jpeg_comment_segment(comment: bytes) -> bytes:
"make a JPEG comment/COM segment"
return make_jpeg_variable_segment(0xFFFE, comment)
# open source image
with Image.open("foo.jpeg") as im:
# save out with new JPEG comment
im.save('bar.jpeg', extra=make_jpeg_comment_segment("hello world".encode()))
# read file back in to ensure comment round-trips
with Image.open('bar.jpeg') as im:
print(im.app['COM'])
print(im.info['comment'])
Note that in my initial attempts I tried appending the comment segment at the end of the file, but Pillow wouldn't load this comment even after calling the .load() method to force it to load the entire JPEG file.
Update: The upcoming version Pillow version 9.4.0 will support this by passing a comment parameter while saving, e.g.:
with Image.open("foo.jpeg") as im:
im.save('bar.jpeg', comment="hello world")
hopefully that makes things easier!
I want to remove exif from an image before uploading to s3. I found a similar question (here), but it saves as a new file (I don't want it). Then I found an another way (here), then I tried to implemented it, everything was ok when I tested it. But after I deployed to prod, some users reported they occasionally got a problem while uploading images with a size of 1 MB and above, so they must try it several times.
So, I just want to make sure is my code correct?, or maybe there is something I can improve.
from PIL import Image
# I got body from http Request
img = Image.open(body)
img_format = img.format
# Save it in-memory to remove EXIF
temp = io.BytesIO()
img.save(temp, format=img_format)
body = io.BytesIO(temp.getvalue())
# Upload to s3
s3_client.upload_fileobj(body, BUCKET_NAME, file_key)
*I'm still finding out if this issue is caused by other things.
You should be able to copy the pixel data and palette (if any) from an existing image to a new stripped image like this:
from PIL import Image
# Load existing image
existing = Image.open(...)
# Create new empty image, same size and mode
stripped = Image.new(existing.mode, existing.size)
# Copy pixels, but not metadata, across
stripped.putdata(existing.getdata())
# Copy palette across, if any
if 'P' in existing.mode: stripped.putpalette(existing.getpalette())
Note that this will strip ALL metadata from your image... EXIF, comments, IPTC, 8BIM, ICC colour profiles, dpi, copyright, whether it is progressive, whether it is animated.
Note also that it will write JPEG images with PIL's default quality of 75 when you save it, which may or may not be the same as your original image had - i.e. the size may change.
If the above stripping is excessive, you could just strip the EXIF like this:
from PIL import Image
im = Image.open(...)
# Strip just EXIF data
if 'exif' in im.info: del im.info['exif']
When saving, you could test if JPEG, and propagate the existing quality forward with:
im.save(..., quality='keep')
Note: If you want to verify what metadata is in any given image, before and after stripping, you can use exiftool or ImageMagick on macOS, Linux and Windows, as follows:
exiftool SOMEIMAGE.JPG
magick identify -verbose SOMEIMAGE.JPG
1) I have an image that I converted to a string. It looks like this:
bytesimage = b'iVBORw0KGgoAAAANSUhEUgA.... etc etc
2) I can convert it to an 'bytesimage.png' using:
def StringToImage(self, stringname, imageoutput):
imgdata = base64.b64decode(stringname)
imagename = imageoutput
with open(imagename, 'wb') as f:
f.write(imgdata)
3) But then I want to save that image or string to memory to use in wxpython interface without needing to save the file. I have seen several related questions where the solution is using io.BytesIO, but I just cant connect the steps and both wxpython or PIL don't seem to read the bytes properly.
So to clarify:
I have a image stored in a string DONE
I can convert that to an image (if needed) but dont want to save it DONE
I need that string OR image (whichever is best) saved to memory NEEDS SOLVING
Then I want to be able to use that image in wxpython (I can open in PIL first if required)
Any help would be fantastic!
StringIO seems to be the way to go. It allows you to pass the decoded string directly to PIL.
import base64
from PIL import Image
import StringIO
# Banana emoji (JPG) as a b64 string.
b64_img_str = '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'
# Decode back to the original bytes
new_img_str = base64.b64decode(b64_img_str)
# Use StringIO to provide an in-memory buffer that we can use
# to pass the image string to PIL.
sio = StringIO.StringIO(new_img_str)
img = Image.open(sio)
# Display the image
img.show()
How can I achieve this with Wand library for python:
convert *.png stack_of_multiple_pngs.tiff
?
In particular, how can I read every png image, pack them into a sequence and then save the image as tiff stack:
with Image(filename='*.tiff') as img:
img.save(filename='stack_of_multiple_pngs.tiff')
I understand how to do it for gifs though, i.e. as described in docs. But what about building a sequence as a list and appending every new image I read as a SingleImage()?
Having trouble figuring it out right now.
See also
With wand you would use Image.sequence, not a wildcard filename *.
from wand.image import Image
from glob import glob
# Get list of all images filenames to include
image_names = glob('*.tiff')
# Create new Image, and extend sequence
with Image() as img:
img.sequence.extend( [ Image(filename=f) for f in image_names ] )
img.save(filename='stack_of_multiple_pngs.tiff')
The sequence_test.py file under the test directory will have better examples of working with the image sequence.
When importing an image I receive a different value than when I create an image. If I import the image
img = open('16x9.gif','rb')
img.read().encode('base64')
# 'R0lGODlhEAAJAIAAAAAAAAAAACH5BAEAAAAALAAAAAAQAAkAAAIKhI+py+0Po5yUFQA7\n'
But, If I create the image in cStringIO:
import cStringIO
import base64
import Image
tmp = cStringIO.StringIO()
img = Image.new('RGB', (16,9))
img.save(tmp, format='GIF', transparency=0)
base64.b64encode(tmp.getvalue())
# Response truncated for readability
# 'R0lGODdhEAAJAIcAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAADMAAGYAAJkAAMwAAP8AA...
The value returned by this second snippet is different and much longer than the first.
Why are my return values different and how do i get the shorter (see first) base64 value?
The difference is between those images representations is format, as your first string is a gif in 89a format, while your tmp is 87a.
>>> 'R0lGODlh'.decode('base64')
'GIF89a'
>>> 'R0lGODdh'.decode('base64')
'GIF87a'
The only related discussion on the topic I found is this: GIF89A and PIL, so it seems that PIL can load 89a format, but can't create it on his own.
As #delnan pointed out, I was not using the equivalent image.
But, in my search I found that png images return shorter base64 strings than gif images.
Closer to what was retuned from a gif that was made in photoshop.