Images are represented as matrices. Is there a practical way to make sort of frame around the content of the image? (in a monoton color)
Theres a lot of ways to do that. I think the easiest way is just to add an image with everything transparent except for the borders and then draw it on top of the screen every frame.
Like Miguel Pereira says, the easiest way is paste a frame previously made in the image that you want set the frame. You can use PIL like this.
from PIL import Image
img_frame = Image.open("frame_name.png")
img_bg = Image.open("bg_name.png")
img_bg.paste(img_frame, (cord_x, cord_y))
img_bg.show()
You may need to resize one of the images to fit
Related
I want to create a basic video editing application where the user can import video clips and then use symmetry (vertical or horizontal) and offsets on their videos. How feasible is this?
For instance, consider the following image:
Right-symmetry:
Image offset to the top-left:
If that last image is confusing, basically you can think of it as the images repeating one next to the the other in a grid, infinitely, such that they're symmetric. Then, you can select a window of this grid equal to the size of the original image. Eg. the red square represents the window:
This is very feasible. Opencv can do all of this frame by frame. Although it would probably take sometime for high quality/long videos. If you want to know how to do these operations, I would open seperate questions. mirroring can for example be done by cv2.flip().
You can use the .flip () method present in the cv2 library. First enter the image with cv2.imread (path). Then to make the mirror effect you have to create a insert cv2.flip (image, 0).
Just as reported below:
image = cv2.imread(path)
mirrow = cv2.flip(image, 0)
I use python pillow to do a easy gif image reverse,but I found that the image has become more size(10m) than before(1m). Anyone know how to make it?
And here is my code:
from PIL import Image, ImageSequence
from PIL import ImagePalette
with Image.open('sd.gif') as im:
if im.is_animated:
frames = [f.copy() for f in ImageSequence.Iterator(im)]
frames.reverse()
frames[0].save('out.gif', save_all=True, append_images = frames[1:])
I can't tell for sure without examining the actual images, but I can guess what likely happened:
Some gifs are optimized with a method that finds pixels in each frame where nothing is changing (or changing only very slightly) from frame to frame, and make them transparent instead of storing the color for each pixel, to reduce the amount of data. For some gifs with large static areas in many consecutive frames this can be very efficient way to reduce file size.
When you are reversing the GIF, the frames must be unoptimized first, otherwise there would be transparent areas without any data. This can increase file size quite a bit. The difference may vary from one image to another.
You probably can solve this by running some gif optimization algorithm after the new image is created.
I am trying to extract a subimage from a scanned paper like this:
https://cloud.kopa.ch/index.php/s/gGZm5xeMYlPfU81
The extracted images should be georeferenced and added to a webmap service, but thats not the question here.
How can I get the frame / its pixel coordinates to crop the image?
I am also free in creating the "layout" (similar to the example), which means I could add markers to get the frame better after scanning it again.
The workflow is:
generate layout - print map - draw on the map - scan it - crop "map-frame" - georeferencing this frame - show it on a webmap
The "map-frames" are preprocessed and I know their location/extent
Has anybody an idea how to crop the (scanned) images automatically to this "map-frame"?
I have to work with python and have the packages PIL, pillow and imagemagick for the image processing
Thanks for you help!
If you need more information, don't hesitate to ask
Here's an example I adapted form the Pillow docs, check them out for any further processing that you might need to perform:
from Pillow import Image
Image.open("/path/to/image.jpg")
box = (100, 100, 400, 400)
region = im.crop(box)
Also, it might prove valuable to search Stack Overflow for this kind of operation, I'm sure it has been discussed earlier.
As for finding the actual rectangle to crop you'll have to do some form of image analysis. In it's simplest form, conceptually that could be something along these lines:
Applying an S-curve filter to a black-and-white representation of your image
Iterate over all of the pixels in the image
Keep track of horizontal and vertical lines that has sufficiently black pixel values.
Use this data to determine the bounding box of the portion of the image your interested in.
Depending on your needs you might want to look into some computer vision library instead, which are well optimized for this and similar tasks. The one that springs to mind is OpenCV which is I would guess is well optimized and documented, and there's a python module available as well.
I'm making live video GUI using Python and Glade-3, but I'm finding it hard to convert the Numpy array that I have into something that can be displayed in Glade. The images are in black and white with just a single value giving the brightness of each pixel. I would like to be able to draw over the images in the GUI so I don't know whether there is a specific format I should use (bitmap/pixmap etc) ?
Any help would be much appreciated!
In the end i decided to create a buffer for the pixels using:
self.pixbuf = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB,0,8,1280,1024)
I then set the image from the pixel buffer:
self.liveImage.set_from_pixbuf(self.pixbuf)
I think these are the steps you need:
use scipy.misc.toimage to convert your array to a PIL image
check out the answer to this question to convert your PIL image to a cairo surface
use gdk_pixbuf_get_from_surface to convert this to a pixbuf (I don't know it's name in the python api)
make a Gtk.Image out of this using Gtk.Image.new_from_pixbuf
I'm sorry it needs so many conversion steps.
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.