computer-vision | opencv-based comptuer vision experiments | Computer Vision library
kandi X-RAY | computer-vision Summary
kandi X-RAY | computer-vision Summary
opencv-based comptuer vision experiments
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Top functions reviewed by kandi - BETA
- Draws the body of the object .
- Draws the LID .
- Identify a rectangle .
- Main function .
- Draws the image .
- Initialize the scene .
- Extract decals from image .
- Mark the face as face .
- Initializes the glut .
computer-vision Key Features
computer-vision Examples and Code Snippets
Community Discussions
Trending Discussions on computer-vision
QUESTION
I used the code below to generate histograms of a colored image using 2 methods :
Method 1 :-
- Using cv2.calcHist() function to calculate the frequency
- Using plt.plot() to generate a line plot of the frequency
Method 2 :-
- Using plt.hist() function to calculate and generate the histogram (I added bin=250 so that the 2 histograms are consistent)
Observation : Both histograms are roughly similar. The 1st histogram (using plt.plot) looks pretty smooth. However the 2nd histogram (using plt.hist) has additional spikes and drops.
Question : Since the image only has int values there shouldn't be inconsistent binning. What is the reason for these additional spikes and drops in the histogram-2 ?
...ANSWER
Answered 2021-Jun-06 at 08:34bins=250
creates 251 equally spaced bin edges between the lowest and highest values. These don't align well with the discrete values. When the difference between highest and lowest is larger than 250, some bins will be empty. When the difference is smaller than 250, some bins will get the values for two adjacent numbers, creating a spike. Also, when superimposing histograms, it is handy that all histograms use exactly the same bin edges.
You need the bins to be exactly between the integer values, setting bins=np.arange(-0.5, 256, 1)
would achieve such. Alternatively, you can use seaborn's histplot(...., discrete=True)
.
Here is some code with smaller numbers to illustrate what's happening.
QUESTION
I'm currently following this tutorial as part of an university assignment where we are supposed to implement canny edge detection ourselfes. Applying the gaussian blur worked without any problems but now I'm trying to display the magnitude intensity as shown on the website.
I implemented the functions as seen on the mentioned website and created a function for running the canny edge detection. Currently this is what the function looks like:
...ANSWER
Answered 2021-May-27 at 16:22I think there might be an issue with ndimage.filters.convolve. I got similar results as you. But the following seems to work fine using Python/OpenCV
Input:
QUESTION
I am trying to use bitwise operations. In the code below I use 2 images (img1, img2). I create two masks using img2 (gray_inv and gray_test).
...ANSWER
Answered 2021-May-26 at 22:30For the effect you’re describing you don’t want a bit-wise OR. You want to multiply the values. So output = input1 * input2 / 255
.
QUESTION
I have tried Read api of azure for reading text from image/pdf (https://eastus.dev.cognitive.microsoft.com/docs/services/computer-vision-v3-2/operations/5d986960601faab4bf452005/console) and it works correctly then I tried using code
...ANSWER
Answered 2021-May-14 at 02:15It is by design as the doc indicated:
When you call the Read operation, the call returns with a response header called 'Operation-Location'. The 'Operation-Location' header contains a URL with the Operation Id to be used in the second step. In the second step, you use the Get Read Result operation to fetch the detected text lines and words as part of the JSON response.
The response body is empty, you can Operation-Location
in the response header.
Just try the code below to get the Operation-Location
and final result:
QUESTION
Sorry if my description is long and boring but I want to give you most important details to solve my problem. Recently I bought a Jetson Nano Developer Kit with 4Gb of RAM, finally!, and in order to get, which I consider, the best configuration for object detection I am following this guide made by Adrian Rosebrock from Pyimagesearch:
https://www.pyimagesearch.com/2020/03/25/how-to-configure-your-nvidia-jetson-nano-for-computer-vision-and-deep-learning/ Date:March, 2020. A summary of this guide is the following:
- 1: Flash Jetson Pack 4.2 .img inside a microSD for Jetson Nano(mine is 32GB 'A' Class)
- 2: Once inserted on the Nano board, configure Ubuntu 18.04 and get rid of Libreoffice entirely to get more available space
- 3: Step #5: Install system-level dependencies( Including cmake, python3, and nano editor)
- 4: Update CMake (without any errors)
- 5: Install OpenCV system-level dependencies and other development dependencies
- 6: Set up Python virtual environments on your Jetson Nano( succesfully installed virtualenv and virtualenvwrapper without errors including the bash file edition with nano)
- 7: Create virtaul env with python 3 and install protobuf and libprotobuf to get an more efficient Tensorflow. Succesfully installed. It took an hour to finish, that's normal
- 8: Here comes the headbreaker: install numpy and cython inside this env and check it importing numpy library When I try to do this step I get: Illegal instruction(core dumped) as you can see in the image: [Error with Python3.6.9]: https://i.stack.imgur.com/rAZhm.png
I said, well let's continue with this tutorial anyway:
- 9: Install Scipy v1.3.3: everything is ok with first three lines, but when I have to use python to execute the stup.py file, IT shows up again(not the clown). [Can't execute this line either]: https://i.stack.imgur.com/wFmnt.jpg
Then I ran an experiment, I have created this "p2cv4" env with Python 2, installed numpy and tested it: [With Python 2]: https://i.stack.imgur.com/zCWif.png
I can exit() whenever I want and execute other lines that use python So I concluded that is a python version issue. When I want to execute any python code, terminal ends the program with core dumping, apt-get or pip DO NOT show any errors. And I want to use python 3 because someday in the future a package or library will require python 3.
For python 3 last version for the Jetson Nano is 3.6.9, and idk which version was currently active in March, 2020, like the one Adrian used at that time
In other posts I read that this SIGILL appears when a package or library version like Numpy of TF is not friendly anymore with a specific old or low power CPU, like in this posts: Illegal hardware instruction when trying to import tensorflow, https://github.com/numpy/numpy/issues/9532
So I want to downgrade to a older python version like 3.6.5 or 3.5 but I can't find clear steps to do so in Ubuntu. I thinks this will fix this error and let me continue with configurations on the Jetson Nano.
The pyimageseach guide uses Python 3.6 but it do not specifies if is last 3.6.9 or another. If is not python causing this error let me know. HELP please!
...ANSWER
Answered 2021-Jan-09 at 15:30I had this very same problem following the same guide. BTW, in this scenario, numpy worked just fine in python when NOT in a virtualenv. GDB pointed to a problem in libopenblas.
My solution was to start from scratch with a fresh image of jetson-nano-4gb-jp441-sd-card-image.zip and repeat that guide without using virtualenv. More than likely you are the sole developer on that Nano and can live without virtualenv.
I have followed these guides with success: https://qengineering.eu/install-opencv-4.5-on-jetson-nano.html
Skip the virtualenv portions https://www.pyimagesearch.com/2019/05/06/getting-started-with-the-nvidia-jetson-nano/
I found this to also be required at this point: "..install the official Jetson Nano TensorFlow by.."
QUESTION
Using imageio.imread
instead of scipy.misc.imread
(because it is depreciated) is giving me an issue. I want to perform something like this but using imageio
:
ANSWER
Answered 2021-Apr-29 at 12:01The initial error is located here:
QUESTION
I receive this error:
...Message":"An error has occurred.","ExceptionMessage":"Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[OCR.Models.UserDto]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.\r\nTo fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.
ANSWER
Answered 2021-Apr-18 at 22:19The message states that your JSON is most likely not a collection but a single object, and it feels like it's of type Application
(in your code - nested class)
Try changing this:
QUESTION
through a computer-vision program and object recognition I get arrays like this, which describes rectangles around the recognized objects:
...ANSWER
Answered 2021-Mar-31 at 10:51Here is the answer. I hope you know using for loops in python.
QUESTION
I'm looking for services or scripts that can help to generate images for computer vision machine learning tasks. Not something like this where they just put together several layers of objects over other objects but more a like a 3D generation of objects in different environments.
...ANSWER
Answered 2021-Jan-30 at 13:29I'm not aware of an out-of-the-box solution where you can create arbitrary objects and environments but if you are fine using Blender, here is an example how you can use Blender to automatically create images as a training set for machine learning algorithms.
QUESTION
I am trying to increase the brightness of a gray-scale image. To do that I want to create a spline. But when I am trying to use scipy.interpolate.UnivariateSpline, it is raising an error.
Traceback:
...ANSWER
Answered 2021-Jan-07 at 08:40Indeed, you cannot fit a cubic spline with three points: even a single cubic parabola has four parameters.
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You can use computer-vision like any standard Python library. You will need to make sure that you have a development environment consisting of a Python distribution including header files, a compiler, pip, and git installed. Make sure that your pip, setuptools, and wheel are up to date. When using pip it is generally recommended to install packages in a virtual environment to avoid changes to the system.
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