Concatenating raw files
Hi, just a simple question, is it possible to concatenate 2 raw files to generate a new one whose duration is the sum of the two files taken as input? Thanks, Pedro
set biases while using metavision_simple_viewer.py
I am trying to set biases while using metavision_simple_viewer.py, but I have no idea how to make it in the absence of specific code examples. Sorry, I'm not good at using Python, so this question might seem a bit silly.
Help generating an event rate per allocation period plot
I am running the following code to plot event rates as a function of allocation time. Unfortunately, python crashes without any error when I call histo for the first time. Looking at it as far as I can, it seems the error is occurring on the C side. I
Refractory period/Pixel reset
Hello, I have a question regarding the TDRSTN pin of the EVK3 for GENX320. For caracterization, the datasheet indiates that (page 32) : Does this signal have the same effect as the bias_refr bias (https://docs.prophesee.ai/stable/hw/manuals/biases.html?highlight=refractory%20period)
Start/stop recording in same session: Different video lengths
Dear all, I am trying to acquire and store different videos in the same session. I was finally able to do it by using the RawReader class instead of the EventIterator, and with a proper order in the device.get_i_events_stream() function calls. If I run
Why do higher frequencies need brighter signals to be detected?
Hello dear Prophesee support team, In my experiments I realized in a constant brightness level higher frequencies signals (exp. 1KHz) cannot be detected as much as lower frequency signals (exp. 10~100Hz); meaning much less events are detected in higher
Extrinsic Calibration Issue- Unable to detect LEDs
Hi I've been trying to use Arduino 2560 to blink 2 LEDs at different frequencies(150&200Hz) - code attached below. However, it seems like LEDs aren't being detected by the Prophesee EVK4 camera - (bias settings are at default (recording attached)) when
Pulse signal stopping problem during master-slave camera synchronization
Hello, I would like to ask you about the stop pulse signal: experiment procedure: 1. First synchronization: After compiling SDK: metavision_hal_sync, start the slave first and then the host. There is no problem with synchronization. Note: The USB data
Using OpenEB on Raspberry Pi 5
Hello, i'm running into a problem when trying to use the EVK3 on my Raspberry Pi 5. I compiled from source and even used ctest to verify the functionality. But when i try to launch for example metavision_viewer i get the following error: [HAL][ERROR]
Please ask metavision_sdk_get_started.cpp why the screen flips left and right after starting EVS to start collecting, thank you!
Please consult metavision_sdk_get_started.cpp. After starting EVS to start collecting, the screen flips left and right. For example: In the pictures and videos, the text on the side of the book is: QT5 development and examples. Comparing the actual object
Python RAW File decoder
Hello, In this documentation EVT2 RAW File decoder — Metavision SDK Docs 4.6.0 documentation (prophesee.ai) I can see that there is a code to extract the CD events as well as External Trigger Events in two different CSV files from a RAW file. Is there
[Grab HAL Error or Warning message]
Hi, I want to ask is it possible to grab the error message like NonMonotonicTimeHigh with Python API? I plan to detect during my recording/ live view session if I grab this error then I will stop or do something on my code. Thanks
Sensor Latency Gen 4.1
Hello I'm performing some experiments with PIV laser pulses and I see that even though here is specified that the max latency of the sensor is 200 us Temporal precision of Prophesee sensor's readout It seems that I'm having a higher latency. In the Image
Bypass Bias range check in python
Hi all, Do you know how we can bypass bias range check with the python API please provide some example the documentation has none and I am lost.
Error while compiling metavision_sdk_get_started
Hi, I have an error while trying to compile the file metavision_sdk_get_started. PS C:\Users\ahamm\Documents\MA4\Project_event_camera\Code\PROPHESEE\core> python metavision_sdk_get_started.py Traceback (most recent call last): File "C:\Users\ahamm\Documents\MA4\Project_event_camera\Code\PROPHESEE\core\metavision_sdk_get_started.py",
Dense Optical Flow Estimation - Speed Values
Hello, I am using the dense optical flow: code (https://docs.prophesee.ai/stable/samples/modules/cv/dense_flow_py.html) to estimate the speed and position of the water drops while spraying. I am using the triplet matching method. A part of the results
Different definitions of contrast
Hello, I was wondering why contrast was defined differently between the IMX636 sensor and the GENX320 : For IMX636 : For GENX320 : If we want to plot the S-curve, what influences the choice between plotting pixel response probability in function of log-contrast
How to select event data format to generate on GENX320
Hello, I'm using GENX320 and I'd like to generate events in the EVT2.0 format instead of the default EVT 2.1 to use the evt to csv decoding functions from the sdk. I can't find this information on the datasheet and i can't change the data format on metavision
How to use I_ROI in python I am trying to do some blob detection and then use that to set I_ROI.
Can you help me with this approach and code.
Sample not running in new version
Hello, With the new release Metavision SDK (4.6) I am unable to open samples (ex. metavision_time_surface.py). But with version 4.53 there is no problem. The following error is shown: ImportError: DLL load failed while importing _errors: The specified
Quantifying Signal Strength
I'm trying to quantify the strength of a signal at different accumulation periods, from 100us up. Typically I would use SNR for this, but in the case of an event sensor, that metric is mostly irrelevant. Can someone recommend a strong candidate for quantifying
Why do the OFF events come first in a moving object?
Hello, In this example the spinner end is spinning from left to right (clockwise). Why are the first events happening OFF events? Because the contour of ON events also do not look round, so I was wondering how the camera records the movement.
Ask for help
Hello, I would like to ask what is the difference between setting bias_diff_off to -20 and 20?
How is equivalent frame rate calculated?
Hello and good day, As I know frame rate is not a defined parameter in event-based cameras but is there a formula to estimate how fast of a change in the scene can be detected? In Prohphesee's website more than 10000 fps is mentioned as equivalent temporal
"Passthrough Not Supported, GL Disabled, ANGLE Error in Prophesee on Windows"
Bonjour Madame/Monsieur, I'm encountering an issue when running Prophesee on my Windows. The error message I receive is: ``` C:\Program Files\Prophesee>[11660:0516/100937.361:ERROR:gpu_init.cc(486)] Passthrough is not supported, GL is disabled, ANGLE
Flickering bars on event stream
I have a Prophesee EVK4 camera and I'm noticing a strange occurrence when attempting to record a stream with the camera face down. There is constant bar flickering across the stream. Most other orientations are completely fine; it only falls apart with
Request camera information
Hello, the picture is the information of my camera. I would like to know what the unit of the contrast threshold of this camera is? And what is the range of each parameter? Thank you.
EVT3 NonMonotonicTimeHigh error happened
Hi All I'm trying to use four EVT3 in one PC. I use metavison studio version 4.5 to open four EVT3 camera. Sometimes it will occur NonMonotonicTimeHigh error, it happened randomly not always in the same camera. I found this document from prophesee website,
GenericProducerAlgorithm::is_done() does not change status automatically
Hello, I use Metavision::camera for reading from a file or a camera, and GenericProducerAlgorithm to get events (in the same way as in the metavision_player example) Now I want to close the application when all events was read from a file and processed
RCT value of GENX320
Hello, I have a question regarding the RCT (Ramp Contrast Threshold) value of the GENX320 from the datasheet. I don't understand how RCT=50% if NCT=30% : Let's suppose that NCT=30%. Using the values of the experimental setup for the RCT measurement, if
Using Prophesee camera for paint thickness estimation
Hello, I want to use the Prophesee camera, EVK4, for estimating the paint thickness while spraying. Is this possible to measure the size and velocity of the tiny paint particles using your camera? Is there any code or instruction that I can use? Thank
ColorPalette in metavision_simple_viewer.py
Hi, All! When I change ColorPalette in metavision_simple_viewer.py I get these error: Code lines 55, 56: As the same time ColorPalette with Light, Dark and CoolWarm is working. How can I manage with this error? Best Regards, Rafael.
Why does the sensor detect better changes in higher initial light level?
Hello, I have a question regarding CDP (Contrast Detection Probability) graphs and contrast sensitivity, Why does the sensor have a higher chance of detecting the changes (contrast) when the initial light level is brighter? What is the reasoning or mechanism
Reduce resolution of a recording
Hello, I am running some recorded .raw data with 1280*720 resolution and I would like to make some comparisons on how this would work on a 640*480 resolution. I have been searching on how to do this and I have seen the posibility of applying a ROI filter
Delayed response of events in Low Light Conditions.
Hii, my experiment consist in a black rotating dot with a background light to generate contrast. When I keep all conditions the same only changing the light intensity of the background light I notice that there is like a time delay or a latency (I dont
High latency in generating negative events
Hello, In an extremely dark environment, a laser creates a point light source on the IMX636 and moves at a constant speed. According to the imaging principle of an event-based camera, the time for the point light source to generate positive and negative
Measuring Pixel array current GENX320
Hello, Is there a pin on the GENX320 EVK3 kit where it possible to measure the total current generated by the photodiodes of the pixel matrix ? I'm trying to measure dark current from the pixel's photodiode. For that, the closest i got to the value of
Help! how to deal with the problem?
OS: Windows 11 Professional (23H2) Error: Metavision studio internal error, code 3221225785 signal null
Video writing for spatter tracking
Hello, I am using the metavision_spatter_tracking.py code with these parameters: python metavision_spatter_tracking.py -i recording.raw --cell-width 7 --cell-height 7 --activation-ths 10 --accumulation-time-us 50 -f 3 -o video I want to save the video
How to record in stereo?
Hello. I'm connecting 2 event cameras in stereo. I already did the synchronization by using the metavision_sync.py algorithm but I couldn't find out how to start to record with both cameras at the same time. I used the metavision_simple_recorder.py but
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