I need to find a way to re-size an input raster image (such as jpg) to a specified width/height resolution (given in pixels). It would be great if PyQt while resizing a new image would keep an original image's aspect ratio (so there is no stretching but scaling only).
src = '/Users/usrName/Images/originalImage.jpg' (2048x1024) (rectangular image 2:1 ratio)
dest= '/Users/usrName/Images/originalImage_thumb.jpg' (64x64) (output image is square 1:1 ratio).
Thanks in advance!
POSTED RESULTED FUNC:
...could be used to resize and to convert an image to any format QT supports so far... such as: 'bmp', 'gif', 'jpg', 'jpeg', 'png', 'pbm', 'tiff', 'svg', 'xbm'
def resizeImageWithQT(src, dest):
pixmap = QtGui.QPixmap(src)
pixmap_resized = pixmap.scaled(720, 405, QtCore.Qt.KeepAspectRatio)
if not os.path.exists(os.path.dirname(dest)): os.makedirs(os.path.dirname(dest))
pixmap_resized.save(dest)
Create a pixmap:
pixmap = QtGui.QPixmap(path)
and then use QPixmap.scaledToWidth or QPixmap.scaledToHeight:
pixmap2 = pixmap.scaledToWidth(64)
pixmap3 = pixmap.scaledToHeight(64)
With a 2048x1024 image, the first method would result in an image that is 64x32, whilst the second would be 128x64. Obviously it is impossible to resize a 2048x1024 image to 64x64 whilst keeping the same aspect ratio (because the ratios are different).
To avoid choosing between width or height, you can use QPixmap.scaled:
pixmap4 = pixmap.scaled(64, 64, QtCore.Qt.KeepAspectRatio)
which will automatically adjust to the largest size possible.
To resize the image to an exact size, do:
pixmap5 = pixmap.scaled(64, 64)
Of course, in this case, the resulting image won't keep the same aspect ratio, unless the original image was also 1:1.
Related
I would like to resize images using OpenCV python library.
It works but the quality of the image is pretty bad.
I must say, I would like to use these images for a photo sharing website, so the quality is a must.
Here is the code I have for the moment:
[...]
_image = image
height, width, channels = _image.shape
target_height = 1000
scale = height/target_height
_image = cv2.resize(image, (int(width/scale), int(height/scale)), interpolation = cv2.INTER_AREA)
cv2.imwrite(local_output_temp_file,image, (cv2.IMWRITE_JPEG_QUALITY, 100))
[...]
I don't know if there are others parameters to be used to specify the quality of the image.
Thanks.
You can try using imutils.resize to resize an image while maintaining aspect ratio. You can adjust based on desired width or height to upscale or downscale. Also when saving the image, you should use a lossless image format such as .tiff or .png. Here's a quick example:
Input image with shape 250x250
Downscaled image to 100x100
Reverted image back to 250x250
import cv2
import imutils
image = cv2.imread('1.png')
resized = imutils.resize(image, width=100)
revert = imutils.resize(resized, width=250)
cv2.imwrite('resized.png', resized)
cv2.imwrite('original.png', image)
cv2.imwrite('revert.png', revert)
cv2.waitKey()
Try to use more accurate interpolation techniques like cv2.INTER_CUBIC or cv2.INTER_LANCZOS64. Try also switching to scikit-image. Docs are better and lib is more reach in features. It has 6 modes of interpolation to choose from:
0: Nearest-neighbor
1: Bi-linear (default)
2: Bi-quadratic
3: Bi-cubic
4: Bi-quartic
5: Bi-quintic
What does keras.preprocessing.image.load_img do during image resizing?
In the following statement, target size is set to 128x128.
image1 = img_to_array(image.load_img(img, target_size=(128,128))) / 255
What if I load 100x100 size image?
Will it leave the image as it is or will it zoom to 128x128 size?
It will actually resize it to the target size!
If the image size is smaller than the target size it will be stretched to fit the desired size.
I am writing a handwriting recognition app and my inputs have to be of a certain size (128x128). When I detect a letter it looks like this:
That image for instance has a size of 40x53. I want to make it 128x128, but simply resizing it lowers the quality especially for smaller images. I want to somehow fill the rest up to 128x128 with the 40x53 in the middle. The background color should also stay relatively the same. I am using Python's opencv but I am new to it. How can I do this, and is it even possible?
Here you can get what you have asked using outputImage. Basically I have added a border using copyMakeBorder method. You can refer this for more details. You have to set the color value as you want in the value parameter. For now it is white [255,255,255].
But I would rather suggest you to resize the original image, seems like it is the better option than what you have asked. Get the image resized you can use resized in the following code. For your convenience I have added both methods in this code.
import cv2
import numpy as np
inputImage = cv2.imread('input.jpg', 1)
outputImage = cv2.copyMakeBorder(inputImage,37,38,44,44,cv2.BORDER_CONSTANT,value=[255,255,255])
resized = cv2.resize(inputImage, (128,128), interpolation = cv2.INTER_AREA)
cv2.imwrite('output.jpg', outputImage)
cv2.imwrite('resized.jpg', resized)
I believe you want to scale your image.
This code might help:
import cv2
img = cv2.imread('name_of_image', cv2.IMREAD_UNCHANGED)
# Get original size of image
print('Original Dimensions: ',img.shape)
# Percentage of the original size
scale_percent = 220
width = int(img.shape[1] * scale_percent / 100)
height = int(img.shape[0] * scale_percent / 100)
dim = (width, height)
# Resize/Scale the image
resized = cv2.resize(img, dim, interpolation = cv2.INTER_AREA)
# The new size of the image
print('Resized Dimensions: ',resized.shape)
cv2.imshow("Resized image", resized)
cv2.waitKey(0)
cv2.destroyAllWindows()
I am very new in Python and this is going to be a very basic question.I have a website which is image based and i am developing it using Django.Now i want to resize the image or you can say i want to minimize the size of the images.There are different size of images are avaible,some images are largest in width,some images are largest in height and i want to resize images without changing there shape.
Here are some example what dimensions images are using in my website.
Here the First image is largest in width and the second image is largest in height and they are really big in Dimension.so they need to be resized or rather these images are need to be minimized in size.So i have used the PIL as below.
from PIL import Image,ImageDraw, ImageFont, ImageEnhance
def image_resize(request,image_id):
photo = Photo.objects.get(pk=image_id)
img = Image.open(photo.photo.file)
image = img.resize((1000, 560), Image.ANTIALIAS)
image.save()
so this function returns all the images with width of 1000 and height of 560.But i don't want to resize all the images with same width and height,rather i want to resize each images maintaining there own shape. That is there shape will be same but the images will be resized.How can i do this? i am really new in python.
Do you want to have all images with same width 1000? Try this code. It will resize to at most 1000 as width (if the image's width is less than 1000, nothing changes)
def image_resize(request,image_id):
photo = Photo.objects.get(pk=image_id)
image = Image.open(photo.photo.file)
(w,h) = image.size
if (w > 1000):
h = int(h * 1000. / w)
w = 1000
image = image.resize((w, h), Image.ANTIALIAS)
image.save()
I recall doing this sometime back without any problem except that I used thumbnail method rather than resize. Try it. You need not assign img to image. You can process img and save the same.
# open img
img.thumbnail((1000,560), Image.ANTIALIAS)
# save img
I have some strange problem with PIL not resizing the image.
from PIL import Image
img = Image.open('foo.jpg')
width, height = img.size
ratio = floor(height / width)
newheight = ratio * 150
img.resize((150, newheight), Image.ANTIALIAS)
img.save('mugshotv2.jpg', format='JPEG')
This code runs without any errors and produces me image named mugshotv2.jpg in correct folder, but it does not resize it. It does something to it, because the size of the picture drops from 120 kb to 20 kb, but the dimensions remain the same.
Perhaps you can also suggest way to crop images into squares with less code. I kinda thought that Image.thumbnail does it, but what it did was that it scaled my image to 150 px by its width, leaving height 100px.
resize() returns a resized copy of an image. It doesn't modify the original. The correct way to use it is:
from PIL import Image
#...
img = img.resize((150, newheight), Image.ANTIALIAS)
source
I think what you are looking for is the ImageOps.fit function. From PIL docs:
ImageOps.fit(image, size, method, bleed, centering) => image
Returns a sized and cropped version of
the image, cropped to the requested
aspect ratio and size. The size
argument is the requested output size
in pixels, given as a (width, height)
tuple.
[Update]
ANTIALIAS is deprecated and will be removed in Pillow 10 (2023-07-01). Use Resampling.LANCZOS instead.image.resize((100,100),Image.ANTIALIAS)
Today you should use something like this:
from PIL import Image
img = Image.open(r"C:\test.png")
img.show()
img_resized = img.resize((100, 100), Image.Resampling.LANCZOS)
img_resized.show()