We Keep Coding

PIL doesn't paste properly

I'm trying to make a little weather forecast program which gives you an image with an overview of the weather in python
To get the weather, I'm using openweathermap and it works ok for me, but for the image I'm using PIL to paste the weather icon, but for some reason there's a part of it that's not being pasted, here you can see what the icon should be: https://openweathermap.org/img/wn/04n#2x.png, and here's how it appeared in the image that came out of my script:
Here's the part of the code that generates the image:
def drawImage(d):
img=PIL.Image.open("base.png")
url=f"https://openweathermap.org/img/wn/{d['icon']}#2x.png"
weatherIcon=Image.open(requests.get(url, stream=True).raw)
print(url)
img.paste(weatherIcon, (00, 10))
now=datetime.now()
name="boards/"+now.strftime('%d_%m_%Y_%H_%M_%S')+".png"
img.save(name)
return name
Some notes on this code:
The base.png is just a 720x720 blank image
The d that gets passed in is a dictionary with all the information, but here it only needs the icon, so I'll give this example: {"icon": "04n"}
I got the URL for the image from the website of OpenWeatherMap, see documentation: https://openweathermap.org/weather-conditions

This is happening because the icon image you download has transparency (an alpha channel). To remove that, you can use this answer.
I've simplified it slightly, define the following function:
def remove_transparency(im, bg_colour=(255, 255, 255)):
if im.mode in ('RGBA', 'LA') or (im.mode == 'P' and 'transparency' in im.info):
alpha = im.getchannel('A')
bg = Image.new("RGBA", im.size, bg_colour + (255,))
bg.paste(im, mask=alpha)
return bg
else:
return im
and call it in your code:
weatherIcon=Image.open(requests.get(url, stream=True).raw)
print(url)
weatherIcon = remove_transparency(weatherIcon)
img.paste(weatherIcon, (00, 10))
You might want to adjust that bg_colour parameter.

How do I code a discord bot so it becomes able to post modified gif and/or png profile picture using python PIL?

This code works with users that have .png format in their profile pictures, however, when it comes to users that have .gif animated profile pictures, the code does not work. It gives this error OSError(f"cannot write mode {mode} as PNG") from e OSError: cannot write mode PA as PNG
I attempted to change all .png to .gif but I still had trouble.
ValueError: image has wrong mode
This is the aforementioned code that only works with .png format.
class avatar(commands.Cog):
def __init__(self, client):
self.client = client
#commands.Cog.listener()
async def on_member_join(self, member):
guild = self.client.get_guild(GUILD_ID)
general_channel = guild.get_channel(CHANNEL_ID)
url = requests.get(member.avatar_url)
avatar = Image.open(BytesIO(url.content))
avatar = avatar.resize((285,285));
bigsize = (avatar.size[0] * 3, avatar.size[1] * 3)
mask = Image.new('L', bigsize, 0)
draw = ImageDraw.Draw(mask)
draw.ellipse((0, 0) + bigsize, fill=255)
mask = mask.resize(avatar.size, Image.ANTIALIAS)
avatar.putalpha(mask)
output = ImageOps.fit(avatar, mask.size, centering=(1420, 298))
output.putalpha(mask)
output.save('avatar.png')
img = Image.open('welcomealpha.png')
img.paste(avatar,(1408,265), avatar)
img.save('wel.png')
file = discord.File('wel.png')
channel = self.client.get_channel(CHANNEL_ID)
await channel.send(file=file)
guild = self.client.get_guild(GUILD_ID)
channel = guild.get_channel(CHANNEL_ID)
Could it be that the bot doesn't know how to discern between .gif & .png ? If that's the case, what would be the most efficient way for the bot to recognize which profile picture format each new user has in order to manipulate image/gif accordingly to its format?

The error message is quite clear here: Your original Image object has mode P, i.e. it's a palettised image. When adding an alpha channel as you did, you get mode PA. As Pillow tells you, saving Image objects with mode PA as PNG is not supported. Since you only want to save to some static PNG without any animation, I assume it's save to convert the Image object to mode RGB right in the beginning, such that you get a RGBA mode Image object in the end, which can be saved as PNG without any problems.
I took the following excerpt from your code and added the conversion to mode RGB:
from PIL import Image, ImageDraw, ImageOps
avatar = Image.open('homer.gif').convert('RGB')
avatar = avatar.resize((285, 285))
bigsize = (avatar.size[0] * 3, avatar.size[1] * 3)
mask = Image.new('L', bigsize, 0)
draw = ImageDraw.Draw(mask)
draw.ellipse((0, 0) + bigsize, fill=255)
mask = mask.resize(avatar.size, Image.ANTIALIAS)
avatar.putalpha(mask)
output = ImageOps.fit(avatar, mask.size, centering=(1420, 298))
output.putalpha(mask)
output.save('avatar.png')
The GIF input is Homer; the corresponding Image object has mode P:
The exported PNG is the following; it seems to be the first frame of the GIF:
----------------------------------------
System information
----------------------------------------
Platform: Windows-10-10.0.16299-SP0
Python: 3.9.1
Pillow: 8.1.0
----------------------------------------

NAO fails to save captured image to local computer

I'm trying to save a captured 640x480 RGB image with NAO's front camera to my computer. I'm using python and PIL to do so. Unfortunately, the image just won't save on my computer, no matter what image type or path I use for the parameters of the Image.save()- Method. the image created with PIL contains valid RGB-information though. Here's my code sample from choregraphe:
import Image
def onInput_onStart(self):
cam_input = ALProxy("ALVideoDevice")
nameId = cam_input.subscribeCamera("Test_Cam", 1, 2, 13, 20)
image = cam_input.getImageRemote(nameId) #captures an image
w = image[0] #get the image width
h = image[1] #get the image height
pixel_array = image[6] #contains the image data
result = Image.fromstring("RGB", (w, h), pixel_array)
#the following line doesnt work
result.save("C:\Users\Claudia\Desktop\NAO\Bilder\test.png", "PNG")
cam_input.releaseImage(nameId)
cam_input.unsubscribe(nameId)
pass
Thank you so much for your help in advance!
- a frustrated student

In the comment, you say the code is pasted from choregraphe, so I guess you launch it using choregraphe.
If so, then the code is injected into your robot then started.
So your image is saved to the NAO hard drive and I guess your robot doesn't have a folder named: "C:\Users\Claudia\Desktop\NAO\Bilder\test.png".
So change the path to "/home/nao/test.png", start your code, then log into your NAO using putty or browse folder using winscp (as it looks like you're using windows).
And you should see your image-file.

In order for your code to run correctly it needs to be properly indented. Your code should look like this:
import Image
def onInput_onStart(self):
cam_input = ALProxy("ALVideoDevice")
nameId = cam_input.subscribeCamera("Test_Cam", 1, 2, 13, 20)
image = cam_input.getImageRemote(nameId) #captures an image
w = image[0] #get the image width
h = image[1] #get the image height
pixel_array = image[6] #contains the image data
...
Make sure to indent everything that's inside the def onInput_onStart(self): method.

Sorry for the late response, but it maybe helpful for someone. You should try it with naoqi. Here is the documentation for retriving images
http://doc.aldebaran.com/2-4/dev/python/examples/vision/get_image.html
The original code was not working for me so I made some tweeks.
parser = argparse.ArgumentParser()
parser.add_argument("--ip", type=str, default="nao.local.",
help="Robot IP address. On robot or Local Naoqi: use
'nao.local.'.")
parser.add_argument("--port", type=int, default=9559,
help="Naoqi port number")
args = parser.parse_args()
session = qi.Session()
try:
session.connect("tcp://" + args.ip + ":" + str(args.port))
except RuntimeError:
pass
"""
First get an image, then show it on the screen with PIL.
"""
# Get the service ALVideoDevice.
video_service = session.service("ALVideoDevice")
resolution = 2 # VGA
colorSpace = 11 # RGB
videoClient = video_service.subscribe("python_client",0,3,13,1)
t0 = time.time()
# Get a camera image.
# image[6] contains the image data passed as an array of ASCII chars.
naoImage = video_service.getImageRemote(videoClient)
t1 = time.time()
# Time the image transfer.
print ("acquisition delay ", t1 - t0)
#video_service.unsubscribe(videoClient)
# Now we work with the image returned and save it as a PNG using ImageDraw
# package.
# Get the image size and pixel array.
imageWidth = naoImage[0]
imageHeight = naoImage[1]
array = naoImage[6]
image_string = str(bytearray(array))
# Create a PIL Image from our pixel array.
im = Image.fromstring("RGB", (imageWidth, imageHeight), image_string)
# Save the image.
im.save("C:\\Users\\Lenovo\\Desktop\\PROJEKTI\\python2-
connect4\\camImage.png", "PNG")
Be careful to use Python 2.7.
The code runs on your computer not the NAO robot!

How to take snapshot from given region of the screen with python?

Here is my thoughts:
1) snap shot the given region from the screen like (100,100,80,60), save the result as image
2) process the image with OpenCV python interface
Just be first to python and wonder if this is good solution,be specific,wonder how to snapshot with python.
Thanks,

It's fairly simple using CGRectMake in Apple's CoreGraphics api:
CG.CGRectMake(x, y, w, h)
This allows you to define the horizontal/vertical positions, and width/height respectively.
Code:
#!/usr/bin/python
import Quartz
import LaunchServices
from Cocoa import NSURL
import Quartz.CoreGraphics as CG
def screenshot(path, dpi, region = None):
if region is None:
region = CG.CGRectInfinite
image = CG.CGWindowListCreateImage(
region,
CG.kCGWindowListOptionOnScreenOnly,
CG.kCGNullWindowID,
CG.kCGWindowImageDefault)
url = NSURL.fileURLWithPath_(path)
dest = Quartz.CGImageDestinationCreateWithURL(
url,
LaunchServices.kUTTypePNG, 1, None
)
prop = {
Quartz.kCGImagePropertyDPIWidth: dpi,
Quartz.kCGImagePropertyDPIHeight: dpi,
}
Quartz.CGImageDestinationAddImage(dest, image, prop)
Quartz.CGImageDestinationFinalize(dest)
spec = (0, 0, 800, 600) # x, y, w, h
path = '/path/to/screnshot_region.png' # save path
area = CG.CGRectMake(*spec) # set area to cgrect
screenshot(path, dpi=72, region=area) # call function
To use, just call the function:
screenshot(path, dpi=72, region=area)
*dpi will set the image output resolution; leave out the region argument for fullscreen capture. In regards to the OpenCV portion - I don't use it often enough to provide anything at this time.

Python PIL - All areas of PNG with opacity > 0 have their opacity set to 1

Imagine a red circle with a black dropshadow that fades away on top of a fully transparent background. When I open and resave the image with PIL the background remains fully transparent but the dropshadow becomes full black.
The problem appears without even altering the image:
image = Image.open('input.png')
image = image.convert('RGBA')
image.save('output.png')
I want to keep the image looking exactly as the original so that I can crop or resize it.
EDIT: Here's a PNG that demonstrates the effect. It was converted to 8bit by using PNGNQ.
When using the above Python code it comes out as the following:

It looks like PIL currently doesn't support full alpha for PNG8.
There is a patch here for read-only support: http://mail.python.org/pipermail/image-sig/2010-October/006533.html
If you're feeling naughty, you could monkeypatch PIL:
from PIL import Image, ImageFile, PngImagePlugin
def patched_chunk_tRNS(self, pos, len):
i16 = PngImagePlugin.i16
s = ImageFile._safe_read(self.fp, len)
if self.im_mode == "P":
self.im_info["transparency"] = map(ord, s)
elif self.im_mode == "L":
self.im_info["transparency"] = i16(s)
elif self.im_mode == "RGB":
self.im_info["transparency"] = i16(s), i16(s[2:]), i16(s[4:])
return s
PngImagePlugin.PngStream.chunk_tRNS = patched_chunk_tRNS
def patched_load(self):
if self.im and self.palette and self.palette.dirty:
apply(self.im.putpalette, self.palette.getdata())
self.palette.dirty = 0
self.palette.rawmode = None
try:
trans = self.info["transparency"]
except KeyError:
self.palette.mode = "RGB"
else:
try:
for i, a in enumerate(trans):
self.im.putpalettealpha(i, a)
except TypeError:
self.im.putpalettealpha(trans, 0)
self.palette.mode = "RGBA"
if self.im:
return self.im.pixel_access(self.readonly)
Image.Image.load = patched_load
Image.open('kHrY6.png').convert('RGBA').save('kHrY6-out.png')

I think that the problem has been somewhat resolved, but is it possible that you need to set the depth of the alpha channel?