I have an A4 png image with some text in it, it's transparent, my question is, how can I crop the image to only have the text, I am aware of cropping in PIL, but if I set it to fixed values, it will not be able to crop another image that has that text in another place. So, how can I do it so it finds where the text, sticker, or any other thing is placed on that big and empty image, and crop it so the thing fits perfectly?
Thanks in advance!
You can do this by extracting the alpha channel and cropping to that. So, if this is your input image:
Here it is again, smaller and on a chessboard background so you can see its full extent:
The code looks like this:
#!/usr/bin/env python3
from PIL import Image
# Load image
im = Image.open('image.png')
# Extract alpha channel as new Image and get its bounding box
alpha = im.getchannel('A')
bbox = alpha.getbbox()
# Apply bounding box to original image
res = im.crop(bbox)
res.save('result.png')
Here is the result:
And again on a chessboard pattern so you can see its full extent:
Keywords: Image processing, Python, PIL/Pillow, trim to alpha, crop to alpha, trim to transparency, crop to transparency.
from PIL import Image
im = Image.open("image.png")
im.getbbox()
im2 = im.crop(im.getbbox())
im2.save("result.png")
Related
So I have an image and I want to cut it up into multiple images to feed into OCR to read.
image example
I only want the messages with the white bubbles and exclude anything with the grey bubbles. I can't figure out how to make a loop to separate each white bubble.
import numpy as np
from PIL import ImageGrab, Image, ImageFilter
img = Image.open('test1.png').convert('RGB')
na = np.array(img)
orig = na.copy()
img = img.filter(ImageFilter.MedianFilter(3))
whiteY, whiteX = np.where(np.all(na==[255,255,255],axis=2))
top, bottom = whiteY[1], whiteY[-1]
left, right = whiteX[1], whiteX[-1]
You could try using the opencv threshold function, followed by the findContours function. This will, if you threshold the image correctly, give you the 'borders' of the bubbles above. Using that, you could then crop out each text bubble.
Here's a simple example of contours being used:
https://www.geeksforgeeks.org/find-and-draw-contours-using-opencv-python/
Otherwise if you'd like to understand better how the opencv functions I mentioned or those that are used in the article above, have a look at the opencv documentation.
I am trying to crop a image into a circulor form (which works) and then pasting it to a white backround.
from PIL import Image,ImageFont,ImageDraw, ImageOps, ImageFilter
from io import BytesIO
import numpy as np
pfp = Image.open(avatar)
# cropping to circle
img=pfp.convert("RGB")
npImage=np.array(img)
h,w=img.size
alpha = Image.new('L', img.size,0)
draw = ImageDraw.Draw(alpha)
draw.pieslice([0,0,h,w],0,360,fill=255)
npAlpha=np.array(alpha)
npImage=np.dstack((npImage,npAlpha))
Image.fromarray(npImage).save('result.png')
background = Image.open('white2.png')
background.paste(Image.open('result.png'), (200, 200, h, w))
background.save('combined.png')
Heres what the cropped image looks like(It looks like it has a white background but that's it's transparent):
Cropped Image
But then when I paste it to the white background it changes to a square:
Pasted Image
Here is the original image I am working with:
Image
What you're doing is setting the Alpha of any pixel outside that circle to 0, so when you render it, it's gone, but that pixel data is still there. That's not a problem, but it important to know.
Problem
Your "white2.png" image does not have an alpha channel. Even if it's a PNG file, you have to add an alpha channel using your image editing tool. You can print("BGN:", background.getbands()), to see the channels it has. You'll see it says 'R','G','B', but no 'A'.
Solution 1
Replace your paste line with:
background.paste(pfp, (200, 200), alpha)
Here, we use the loaded in avatar as is, and the third argument is a mask which PIL figures out how to use to mask the image before pasting.
Solution 2
Give your white background image an alpha channel.
MS Paint doesn't do this. You have to use something else.
For GIMP, you simply right-click on the layer and click Add Alpha-channel.
Oh, and something worth noting.
Documentation for Paste.
See alpha_composite() if you want to combine images with respect to their alpha channels.
How can I convert a non-transparent PNG file into a transparent GIF file with PIL?
I need it for my turtle-graphics game. I can only seem to transparentize a PNG file, not a GIF file.
It's not obvious, to me at least, how you are supposed to do that! This may be an unnecessary work-around for a problem that doesn't exist because I don't know something about how PIL works internally.
Anyway, I messed around with it long enough using this input image:
#!/usr/bin/env python3
from PIL import Image, ImageDraw, ImageOps
# Open PNG image and ensure no alpha channel
im = Image.open('start.png').convert('RGB')
# Draw alpha layer - black square with white circle
alpha = Image.new('L', (100,100), 0)
ImageDraw.Draw(alpha).ellipse((10,10,90,90), fill=255)
# Add our lovely new alpha layer to image
im.putalpha(alpha)
# Save result as PNG and GIF
im.save('result.png')
im.save('unhappy.gif')
When I get to here, the PNG works and the GIF is "unhappy".
PNG below:
"Unhappy" GIF below:
Here is how I fixed up the GIF:
# Extract the alpha channel
alpha = im.split()[3]
# Palettize original image leaving last colour free for transparency index
im = im.convert('RGB').convert('P', palette=Image.ADAPTIVE, colors=255)
# Put 255 everywhere in image where we want transparency
im.paste(255, ImageOps.invert(alpha))
im.save('result.gif', transparency=255)
Keywords: Python, image processing, PIL, Pillow, GIF, transparency, alpha, preserve, transparent index.
I've been trying to get thisimage to automatically crop to the smallest size possible, removing the transparent bits around it. I can't just crop this image myself manually, as more things will be added on the image like this .
I've been using this code:
from PIL import Image, ImageChops
image=Image.open('headbase1.png')
image.load()
imageSize = image.size
imageBox = image.getbbox()
print(image.getbbox())
cropped=image.crop(imageBox)
cropped.save('headbase_end.png')
It does not crop out the transparency around it, and the bounding box is this (0, 0, 45, 45), which I do not think is right.
Thanks, VOT.
Edit, this does work: Automatically cropping an image with python/PIL with that image, however it refuses to work for my image. .
getbbox doesn't work on PNGs with alpha channels: image.mode == 'RGBA'
First remove the alpha channel and then obtain the bounding box. image.convert('RGB').getbbox()
I have written a python code using PIL and Tkinter where I display an image and put a red circle on the image where a user clicked. Here is the relevant code.
def paint_img(event, canvas):
x, y = event.x, event.y
image_draw.ellipse((x-10, y-10, x+10, y+10), fill='red')
canvas._image_tk = ImageTk.PhotoImage(pilImg)
canvas.itemconfigure(canvas._image_id, image=canvas._image_tk)
It seems that it works with some images, but in some cases it displays a grey circle. I used identify on the test images, for the successful one the output is
totestcolor.jpg JPEG 561x549 561x549+0+0 8-bit DirectClass 18.3kb
for the unsuccessful one, the output is:
totestcolor1.jpg JPEG 1533x1095 1533x1095+0+0 8-bit PseudoClass 256c 70.4kb
I want to know why this is happening and if there is any way to output a red circle for the unsuccessful image as well.
That's because the original image is grayscale. You can convert it to full RGB before drawing the red circle. In the PIL library, it is code like this:
pilImg = pilImg.convert("RGB") # or "RGBA" to keep transparency