I need to extract a object of interest (a vehicle ) from a large picture, now I know the 4 coordinates of this vehicle in the picture. How could I crop the image of this vehicle in the picture and then rotate it to 90 degree as shown below
I need to program it in python, but I don’t know which library to use for this functionality ?
You can use PIL (http://www.pythonware.com/products/pil/)
from PIL import Image
im = Image.open("img.jpg")
im.rotate(45)
You also have a crop method ...
You could use PIL and do it like here :
Crop the image using PIL in python
You could use OpenCV and do it like here:
How to crop an image in OpenCV using Python
For the rotation you could use OpenCV's cv::transpose().
Rotating using PIL: http://matthiaseisen.com/pp/patterns/p0201/
Related
Let's assume that I use YoloV3 to detect a human in an image, and I have the bounding box coordinates. Just like the example here:
We can use cv2 to extract the pixels of the bounding box, and the image can be like (200*200). I want to feed this to a model that gets image size (368*368).
The question is:
How can I resize the image from (200 by 200) to (368 by 368)?
What are the possible ways that I can use it to do that?
Thanks,
You can use the openCV library to upscale images with interpolation, for example:
import cv2
new_image = cv2.resize(image, (368,368), interpolation=cv2.INTER_NEAREST)
The interpolation methods available are:
INTER_NEAREST
INTER_LINEAR
INTER_AREA
INTER_CUBIC
INTER_LANCZOS4
I am trying to use python pillow package to enlarge picture and here is my try
from PIL import Image
image = Image.open('Sample.jpg')
new_image = image.resize((1080, 1080))
new_image.save('Output.jpg')
The code is working but the output image loses completely the ratio. How can I enlarge the image without losing the quality?
What you're talking about is image upscaling, which is a more complex problem just than enlarging the image. I recommend looking into image upscaling packages. A lot of them use CNNs for this.
I am trying to de-noise an image that I've made in order to read the numbers on it using Tesseract.
Noisy image.
Is there any way to do so?
I am kind of new to image manipulation.
from PIL import ImageFilter
im1 = im.filter(ImageFilter.BLUR)
im2 = im.filter(ImageFilter.MinFilter(3))
im3 = im.filter(ImageFilter.MinFilter)
The Pillow library provides the ImageFilter module that can be used to enhance images. Per the documentation:
The ImageFilter module contains definitions for a pre-defined set of filters, which can be be used with the Image.filter() method.
These filters work by passing a window or kernel over the image, and computing some function of the pixels in that box to modify the pixels (usually the central pixel)
The MedianFilter seems to be widely used and resembles the description given in nishthaneeraj's answer.
You have to read Python pillow Documentation
Python pillow Documentation link:
https://pillow.readthedocs.io/en/stable/
Pillow image module:
https://pillow.readthedocs.io/en/stable/reference/ImageFilter.html#module-PIL.ImageFilter
How do you remove noise from an image in Python?
The mean filter is used to blur an image in order to remove noise. It involves determining the mean of the pixel values within a n x n kernel. The pixel intensity of the center element is then replaced by the mean. This eliminates some of the noise in the image and smooths the edges of the image.
I have an image of 300*300 pixels size and want to convert it into 1500*1500 pixels size using python. I need this because i have to georeferenced this image with 1500*1500 pixel raster image. Any python library function or basic fundamental how to do this are welcome.
You should try using Pillow (fork of PIL = Python Image Library)
Simple like this:
from PIL import Image
img = Image.open("my_image.png")
img.resize((1500, 1500, ))
img.save("new_image.png")
I am trying to increase the height of an image using PIL but I don't want the image to be resized; I actually want a strip of blank pixels at the bottom of the image. Any way of doing this with PIL?
I guess one way would be to make a new image of the required size and copy the old image into it but I can't seem to find the right function to do this.
Oops, just realized you can do image.crop() and it will resize the image for you.