Develop Reference

Convert mp3 song image from png to jpg

I have a set of many songs, some of which have png images in metadata, and I need to convert these to jpg.
I know how to convert png images to jpg in general, but I am currently accessing metadata using eyed3, which returns ImageFrame objects, and I don't know how to manipulate these. I can, for instance, access the image type with
print(img.mime_type)
which returns
image/png
but I don't know how to progress from here. Very naively I tried loading the image with OpenCV, but it is either not a compatible format or I didn't do it properly. And anyway I wouldn't know how to update the old image with the new one either!
Note: While I am currently working with eyed3, it is perfectly fine if I can solve this any other way.

I was finally able to solve this, although in a not very elegant way.
The first step is to load the image. For some reason I could not make this work with eyed3, but TinyTag does the job:
from PIL import Image
from tinytag import TinyTag
tag = TinyTag.get(mp3_path, image=True)
image_data = tag.get_image()
img_bites = io.BytesIO(image_data)
photo = Image.open(im)
Then I manipulate it. For example we may resize it and save it as jpg. Because we are using Pillow (PIL) for these operations, we actually need to save the image and finally load it back to get the binary data (this detail is probably what should be improved in the process).
photo = photo.resize((500, 500)) # suppose we want 500 x 500 pixels
rgb_photo = photo.convert("RGB")
rgb_photo.save(temp_file_path, format="JPEG")
The last step is thus to load the image and set it as metadata. You have more details about this step in this answer.:
audio_file = eyed3.load(mp3_path) # this has been loaded before
audio_file.tag.images.set(
3, open(temp_file_path, "rb").read(), "image/jpeg"
)
audio_file.tag.save()

Resizing Image in Python without losing letter quality

I have tried using the following code in order resize my picture, but I lose so much quality that I cannot even read the letters clearly. At first I create it the picture from a string, which has very good quality .
handoverNote = str.encode(handoverNote)
with open("test.png", "wb") as f:
f.write(codecs.decode(handoverNote, "base64"))
image = Image.open("test.png")
image.thumbnail((500, 500), Image.ANTIALIAS)
image.save("test2.png", quality=95)
But after resizing the image looks unreadable or alstmost unrecognizable like in this example:
This is the original image, I get without resizing.
What am I doing wrong here? Is it because I use PNG?

PIL image to array and back

EDIT: Sorry, the first version of the code was bullshit, I tried to remove useless information and made a mistake. Problem stays the same, but now it's the code I actually used
I think my problem is probably very basic but I cant find a solution. I basically just wanted to play around with PIL and convert an image to an array and backward, then save the image. It should look the same, right? In my case the new image is just gibberish, it seems to have some structure but it is not a picture of a plane like it should be:
def array_image_save(array, image_path ='plane_2.bmp'):
image = Image.fromarray(array, 'RGB')
image.save(image_path)
print("Saved image: {}".format(image_path))
im = Image.open('plane.bmp').convert('L')
w,h = im.size
array_image_save(np.array(list(im.getdata())).reshape((w,h)))

Not entirely sure what you are trying to achieve but if you just want to transform the image to a numpy array and back, the following works:
from PIL import Image
import numpy as np
def array_image_save(array, image_path ='plane_2.bmp'):
image = Image.fromarray(array)
image.save(image_path)
print("Saved image: {}".format(image_path))
im = Image.open('plane.bmp')
array_image_save(np.array(im))
You can just pass a PIL image to np.array and it takes care of the proper shaping. The reason you get distorted data is because you convert the pil image to greyscale (.convert('L')) but then try to save it as RGB.

how to reduce png image filesize in PIL

I have used PIL to convert and resize JPG/BMP file to PNG format. I can easily resize and convert it to PNG, but the file size of the new image is too big.
im = Image.open('input.jpg')
im_resize = im.resize((400, 400), Image.ANTIALIAS) # best down-sizing filter
im.save(`output.png')
What do I have to do to reduce the image file size?

PNG Images still have to hold all data for every single pixel on the image, so there is a limit on how far you can compress them.
One way to further decrease it, since your 400x400 is to be used as a "thumbnail" of sorts, is to use indexed mode:
im_indexed = im_resize.convert("P")
im_resize.save(... )
*wait *
Just saw an error in your example code:
You are saving the original image, not the resized image:
im=Image.open(p1.photo)
im_resize = im.resize((400, 400), Image.ANTIALIAS) # best down-sizing filter
im.save(str(merchant.id)+'_logo.'+'png')
When you should be doing:
im_resize.save(str(merchant.id)+'_logo.'+'png')
You are just saving back the original image, that is why it looks so big. Probably you won't need to use indexed mode them.
Aother thing: Indexed mode images can look pretty poor - a better way out, if you come to need it, might be to have your smalle sizes saved as .jpg instead of .png s - these can get smaller as you need, trading size for quality.

You can use other tools like PNGOUT

Resize image twice in Django using PIL

I have a function in which I'm trying to resize a photo twice from request.FILES['image']. I'm using the image.thumbnail() with the Parser as well. This works fine when I create one thumbnail, but in my view if I repeat the exact same thing again, it fails in the parser via IOError cannot parse image. I'm very confused. I've created StringIO files in memory instead of using Django's UploadedFile object as-is and it still does the same thing. Any help is much appreciated.
Suppose I wanted to do the following twice (with two different thumbnailing sizes) all without retrieving the URL twice:
import urllib2
from PIL import Image, ImageFile, ImageEnhance
# create Image instance
file = urllib2.urlopen(r'http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/kemps-ridley-sea-turtle.jpg')
parser = ImageFile.Parser()
while True:
s = file.read(1024)
if not s:
break
parser.feed(s)
image = parser.close()
# make thumbnail
size = (75, 75)
image.thumbnail(size, Image.ANTIALIAS)
background = Image.new('RGBA', size, (255, 255, 255, 0))
background.paste(
image,
((size[0] - image.size[0]) / 2, (size[1] - image.size[1]) / 2))
background.save('copy.jpg')
For instance:
image = parser.close()
image2 = parser.close() # Obviously this doens't work
image2 = image # Obviously this doesn't either but you get what I need to do here
# Do 2 thumbnails with only one original source.
... other code ommitted ...
image.save('copy.jpg')
image2.save('copy.jpg')

If this works once, as you say, the image you retrieved is just fine. There are at least two different ways to get multiple thumbnails out of single PIL images.
You can use PIL's resize method, which will return a resized copy of the original. You just have to calculate the dimensions you'll need if you want to keep the proportions intact.
Use Image.copy() to get a copy of the image.
Like this:
original = parser.close()
...
thumb1 = original.copy()
size = (75,75)
thumb1.thumbnail(size, Image.ANTIALIAS)
...
thumb2 = original.copy()
thumbnail2 = original.resize(size2, Image.ANTIALIAS)
...
This way, the original will not be altered and you can get as many copies as you need.

A simpler solution than copying the original image is to instead reset the file pointer between calls to thumbnail(...) like so:
original.seek(0)

I'm assuming it's failing on the image = parser.close() line with an IOError. so there's probably something wrong with the way ImageFile is getting the image data. Have you tried making reading from a local file instead?
If the parser managed to decode an image, it returns an Image object.
Otherwise, this method raises an IOError exception.
Source.