everybody, i am doing one thing than i want to judge whether one image is a HDR image, if you have any ideas, please shared it with me , thank you ! my friends.
Yes. If AVIF file is tagged with PQ or HLG transfer functions it is HDR. You can use exiftool on these samples to check for that. https://github.com/AOMediaCodec/av1-avif/tree/master/testFiles/Netflix/avif
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I need to use OpenCV with uEye Ethernet Camera. The problem is that I wasn't finding some useful tips regarding some example codes.
The source code provided with the installation is really linked to MFC stuff which is not what I want. It's really complicated to get rid of that, it was causing me so much problems (CWnd, Afx, Dialogs...)
I would like to read some frames from the camera and record some snapshots.
You can find the whole SDK description here: https://en.ids-imaging.com/manuals-ueye-software.html
Just simply make and account and you can access it. The documentation is really good.
I found this document in the internet
http://master-ivi.univ-lille1.fr/fichiers/Cours/uEye_SDK_manual_enu.pdf
the heading says it all actually:
i want to convert a pdf file into several jpg images. This is to be a part of a software coded in c++ (I'm using Qt for my interface if that matters... :)
Preferably i want the images output to be 72 dpi.
Is there a easy way to do this?
Please comment if you need any more information form me, I'm grateful for any help, tips or answer!
Take pdf2image utility, and run it from you program, collecting its output files.
If you really need single executable (why?) — take a look at its source, and rip everything from it.
You should try to use poppler (or xpdf). You'll have full control of the rendering resolution and can take advantage of image output devices (ImageOutputDev) which will render pages to a framebuffer.Saving this framebuffer to jpeg with libjpeg is ,then , pretty straightforward.
I want to make a screen capture utility, so far i am able to capture the screen in regular interval to get a numbered sequence of images and now i want to encode them to a video format preferably flv(because of good compression and web support)
....I tried the ffmpeg.exe for that reason but for some strange reason it did'nt work
on my vista ultimate...only the first picture is encoded while the rest -I dont know what happened to them.
Also I would prefer doing the encoding stuf programatically (using c/c++ library api if any for that purpose) rather than using tools as ffmpeg.exe and i am interested in encoding picture sequence to video not capturing contineouse video directly.
I searched through internet....there are lots of libraries and tutorial for converting between video formats but I did'nt find something usefull for my problem.
I am not verry proficient with video formats and sdk library, I just need a quick way to encode some pictures to video with some basic control (as time interval between two consecutive frames).
So can you help me with some pointers as to which library i should use and how(code fragment and little descriptive answer would greatly help) and please dont recomend any .NET solution I need to learn something out of this and dont want to apply some bruteforce approach to solve the problem.
Sorry for my english....and thanks in advance.
It appears that an .avi file can more or less directly be made of .jpg's:
An AVI file may carry audio/visual data inside the chunks in virtually any compression scheme, including Full Frame (Uncompressed), ..., Motion JPEG.
Also, something very similar has been discussed here before.
I have a huge amount of points data set. so i want to find min and max values from these points set. now i am using normal for loop for this purpose nice it is working but i want to know posibility to use opencv library since i wish to use this library. so plese any one help me. thanks
There are several options. Using OpenCV for this may give you an easy way to use SSE or other partially par
http://docs.opencv.org/search.html?q=minMax&check_keywords=yes&area=default
Some of those can use the GPU to help. Of course, the GPU will only be faster if your data was already in the GPU. Pushing data across the bus onto your video card just for this kind of search would be a net loss.
Use std::max_element() with a single channel cv::Mat like this:
img = img / *max_element(img.begin<float>(), img.end<float>());
No need for OpenCV in this case: it's already in the standard library (std::min_element and std::max_element).
So all I need is a simple function that sets it up (eating incoming PCM RATE (for example: rate near to 44100) It's channels (for example: 2) and -bits (for example: 16) and desirable 128 kb\s rate) and another one that takes PCM data and encodes it into pure MP3 frames.
I know it looks like a silly homework task but I assure you - it is not.
I hope it will be of help to all C++ developers starting with MP3s.
So can anybody please help me with that?
See the example I gave in your other question for the basic usage of Lame. It should contain everything you need.
It's a long time since i messed with this, but Lame lib contains all you need to do it, check out lame.h , there is some test code you could look into.
Personally, I'd be looking at ffmpeg's libavcodec. There's an example file containing an audio_encode_example which ought to be more or less what you're looking for.
See also this question.
Note that not all ffmpeg packagings include mp3 codec support (patent issues) by default, although there's usually some simple way of enabling it.
GStreamer should definitely be able to handle this.
If you are on Windows you can use the GStreamer Winbuilds to get started.