I"m experiencing the same problem a lot of other people are experiencing with openCV, in that when I use the following code, openCV fails to write a video file. I am using openCV 2.4.10 and python 2.7
out = cv2.VideoWriter('C:\motion\output.avi',cv2.cv.CV_FOURCC('X','V','I','D'), 20, (640,480),True)
a viable work around is to replace the second argument with -1, which gives a popup window with coded choices when the program is run. When one of these is selected, the video is created.
The problem is, I am adding it to a motion detection software which writes a 15 second timestamped file every time it detects motion, and obviously selecting a codec manually does not work with this scheme.
Is there a way to direct openCV to select one of these codecs using VideoWriter, or some other method?
THINGS I HAVE TRIED ALREADY:
copying opencv_ffmpeg.dll to python folder and selecting FMP4 codec from FOURCC
While I did not find an alternative way to select the codecs available, I did find the answer to the underlying problem of openCV not finding it's own codecs (which is good because the windows codecs were producing files ~50x larger than those produced by the fmp4 codec).
Access the codecs, copy the files from the opencv\sources\3rdparty\ffmpeg folder to your python27 folder, then change the names from opencv_ffmpeg.dll to opencv_ffmpegXYZ.dll where XYZ = your version of openCV. For example I have openCV 2.4.10 so I changed it to opencv_ffmpg2410.dll. More examples can be found on this question.
OpenCV 2.4 VideoCapture not working on Windows
Related
My goal is to generate (in Python under Windows) a bitmap image rendering any unicode character, including in particular emojis. I have installed several emoji-friendly fonts (including Symbola) for testing purpose.
So far I've tried PIL, matplotlib and pygame, but none of these are able to do it under Windows (the first two apparently can do it on some versions of Linux / MacOS, while pygame is explicitly limited to characters up to 0xffff, which rules out emojis).
I found that reportlab is able to generate a PDF with emojis (while its bitmap renderer fails to properly render them), but I still need to find a way to extract the emoji character from the PDF and convert it to bitmap. I feel like there has to be a simpler way...
NB: this question is related to Rendering Emoji with PIL but I do not necessarily want to use PIL if another library can do the job
I eventually found a solution in Is there any good python library for generating and rendering text in image format?. Although it is based on a third-party executable, as mentioned it is easy to wrap in Python.
Exact steps were as follows:
Install ImageMagick from https://www.imagemagick.org/script/download.php#windows
Set environment variable MAGICK_HOME to installation folder
Install Pillow to be able to manipulate easily the resulting image in Python (conda install pillow)
Download and install the Symbola font from https://fontlibrary.org/en/font/symbola
And my test script:
import os
import subprocess
import PIL.Image
to_render = '🤓'
output_file = 'rendered_emoji.bmp'
subprocess.run([
os.path.join(os.environ['MAGICK_HOME'], 'magick.exe'),
'convert', '-font', 'Symbola', '-size', '50x50',
'-gravity', 'center', f'label:{to_render}', output_file])
image = PIL.Image.open(output_file)
image.show()
I know this question was asked hundred of times, nevertheless I got problems.
I'm working on a new windows (2010 server) systen, installed Python 2.7.9 and OpenCV 2.4.10. I copied opencv_ffmpeg.dll to Python27\opencv_ffmpeg2410.dll. I also installed K-Lite video codecs. If I try to save a video with VideoWriter (MJPG), I get always a file with size 5682 bytes which is not playable. On my old system the same python code works, but over the years I installed several versions of drivers and ffmpeg and whatever. So is there a systematic way to get VideoWriter working if you are on a freshly installed system?
Ok, it was my own fault. All the above steps were ok. I made the error to define cv2.VideoWriter(fname,fourcc,2,(w,h),1) with (w,h) different to the actual frame size (I thought it rescales automaticly). Unfortunately there is no appropriate error message.
So my problem is solved.
i'm trying to utilize PIL to open a jpeg image and assign it to a Tkinter's label.
However whenever i try to open the image i get the same problem as this guy
I tried all the suggestions he got and also the ones i found here but it doesn't seem to fix, by installing PIL or Pillow(i tried that too) during the setup i get :
*** TKINTER support not available
*** JPEG support not available
And whenever i run my code i get an IOError: decoder jpeg not available
I'm using python 2.7.
Can someone provide a good method to make PIL or Pillow work with jpeg support? I've been googling extensively for two days, but all the possible fixes that i found don't seem to work for me
Installing libjpeg-dev should do the trick, as proposed by the link you provided. But if it doesn't help (I ran into that as well) you can consider upgrading to Pillow 3, it looks like you are running Pillow 2. This also helped me getting rid of the errors, don't know why exactly..
I'm trying to use this blog post to convert one pdf to a jpg, however everytime I try to run this simple script I get this exception wand.exceptions.WandError: wand contains no images MagickWand-56' # error/magick-image.c/MagickWriteImage/13001
from wand.image import Image
with Image(filename="myFile.pdf") as img:
img.save(filename="myFile.png")
I'm using the latest version of Wand and Python 3.4.2. The only thing I can think of is possibly a version compatibility issue.
So just to close the question, the problem is missing ghostscript library on mac, as indicated in my comment above:
"maybe then some libraries missing. do you use linux/windows/mac?
check what is required there for pdfs? ghostscript maybe? "
I have a problem with a python program (python 2.7.3, X11 Tkinter, py2app 0.6.4, MacOS X 10.7.4) that I'm trying to export to py2app. The problem only started occurring in the standalone py2app-ified app version of the program. When I run the python source file from which the app was created, the problem does not exist, so I feel it must have something to do with the py2app export.
The problem: When I start the GUI, the first time I try to load a valid image file, the image fails to load, and I get the following error from the PIL Image module:
File "Image.pyc", line 1980, in open
IOError: cannot identify image file
When I then (without closing the GUI or anything) try to open the exact same file, it loads perfectly, no errors or problems. This happens every time, with any image file I try - the first attempt to load fails, subsequent attempts succeed. I should add that after that first error, no image files ever fail to load - even if they are different from the first one.
A few notes:
- The image file is a sequence, and is very large (around 300 MB), so to speed up the loading process, I use a mmap. I have tried removing the mmap step, and handing a regular file object directly to ImagePIL.open it directly, and the problem is unaffected.
- I also tried seeking to the beginning of the file before giving it to ImagePIL.open, but that had no effect.
- The py2app setup file is pretty vanilla - it just includes a few config files and an icon.
Here is the relevant part of the offending image load function:
import Image as ImagePIL
import mmap as m
...
...
def loadImage(self):
errorLog.debug("Attempting to open image \""+self.filenameVar.get()+"\"")
try:
if self.fileMap is not None:
self.fileMap.close()
imageFile = open(self.filenameVar.get(), 'r')
self.fileMap = m.mmap(imageFile.fileno(), 0, prot=m.PROT_READ)
# self.fileMap.seek(0)
self.imageSeries = ImagePIL.open(self.fileMap)
imageFile.close()
except(IOError):
errorLog.exception("Failed to open image \""+self.filenameVar.get()+"\"")
return
I'm pretty stumped - any ideas? Thanks in advance!
Edit: I should add that Tkinter, PIL, and py2app were installed using MacPorts 2.1.2, in the off chance that helps.
It seems that py2app does not include PIL's image plugins into the application bundle even though one of the py2app recipes tries to ensure that they are included.
One thing you could try is to build with "python setup.py py2app --packages=PIL" and then use "import PIL.Image as ImagePIL" to use it.
I don't understand yet why the PIL recipe doesn't work, it might be something in the way MacPorts builds python packages (I don't use MacPorts myself).
The problem is the result of inconsistency between Pillow version 3.0.0 and py2app.
I suggest two solution to avoid PIL (Pillow)
Use opencv instead of PIL.
uninstall the current version of Pillow and install a previous one like 1.7.8