S-Curve : why does pixel response probability go above 100% for GENX320 and not for IMX636 ?
Hello, I measured S-Curves for the IMX636 and the GENX320 and found that above a certain contrast value, pixel reponse probability values go above 100% for GENX320 and saturate at 100% for IMX636 . I saw you have a note on hot pixels for the GENX320.
Can I record only OFF events from hardware?
Hi, There are some variables of the hardware that we can control with Metavision studio, for example the bias and the ROI. Can I control the type of events that I want to record? Because in my specific case I only need to process the OFF events, but the
Readout saturation definition
Hi, is it correct to say that read saturation is a combined effect between event rate and number of active rows in the image? I have done an experiment with different lighting conditions and speeds and I find that improving the lighting conditions, the
How to make sensor to ULP mode with GEN320 EVK?
I read the datasheet, and find ULP_ENB and ULP_RST to set sensor to ULP mode, but I don't know where the pins on the evk. Can you tell me if there any way to ULP mode?
fisheye lens for EVK4 camera
Hi, We have procured a EVK4 camera. We were looking for fish eye lens that is compatible with EVK camera. Can you please recommend/suggest few of them.
Color temperature of light source for electro-optical caratersitics of GENX320
Hello, I'm trying to measure the electro-optical caracteristics of my GENX320 sensor in the same conditions as the datasheet indicates. For the light source, the datasheet indicates : When you look at the wavelength associated to this color temperature
ROI of the raw event data
Dear Sir or Madam, Greetings! I am trying to use event camera to build data set. And I want to reduce the memory size of the event data by restricting the ROI. I use the following command to set the ROI. The problem is that it seems the area out of the
Inquiry about Temporal Resolution and Latency Measurement for EVK4 HD Camera
I was reviewing the technical specifications of the EVK4 HD camera(imx 636 sensor) and noticed that it states the camera has a temporal resolution equivalent to >10k fps. I have a couple of questions regarding this specification: Measurement of Temporal
Why do some pixels keep outputting negative events?
Hi, when I lower the bias_diff_off value (to less than 0), some pixels are always outputting negative events in all rendered frames. In other words, these pixels are always displayed as light blue and no longer change. But positive events are displayed
How does Bias work?
Hello. My sensor is IMX646. And I want to know how the comparator's positive and negative threshold values change after adjusting the bias_diff_off and bias_diff_on values?
Questions about biases
Hello, I have learned that bias_diff_off, bias_diff_on, bias_fo, bias_hpf, bias_refr have no physical units, they are just numbers that represent the deviations. I can get the absolute deviation values of each parameter from Figure 1. But I still have
IMX636 pixel reset
Hello， I would like to know how to set the reset function to a fixed time，there is an example in the IMX636 productspeification which inputting an approximately 3 ms reset pulse from the TDRSTN pin. And, here's the code I added in the metavision_vie
EVK4 sparking curve under different ambient light
Do you have similar probability curves for EVK4 cameras?(To be honest, I can't find out which of your web pages I saw this picture on……)
Maximum temporal resolution of the PPS3MVCD sensor
The datasheet the PPS3MVCD sensor states that the pixel latency is nominally 100μs. According to support, this latency is due to the processing that occurs on the chip and the speed of transfer supported by the USB interface. The pixel delay is nominally
Asking for Probabilistic trigger curve
The trigger of the event camera depends on the change of light intensity, so is it related to the ambient light intensity? What is the probability of different contrast triggering events under different ambient light?
Higher Bias_off more OFF events?
Hi, I would like to know why if we increase the value of the OFF contrast threshold (Bias_off) we end up having more OFF events instead of less. What I understand is that if we increase the threshold is going to be harder to trigger an event but in this
Sensor electro-optical performances
Hello, Were the hot pixels masked or taken into account in the measuring of the electro-optical performances of the GENX320 (for example for the S-curve) ? Cheers, Michael
How to use the hot pixel detection code
Hi, I'd like to use the active pixel detection algorithm from the sdk (https://docs.prophesee.ai/stable/samples/modules/driver/active_pixel_detection.html). When the code is runnig, do i need to have a specific light stimulus for the sensor ? Cheers,
Setting a ROI on GENX320MP and masking the hot pixels in that ROI
Hi, I am trying to to mask some hot pixels in a given ROI on the GENX320 MP. I looked at this page : https://support.prophesee.ai/portal/en/kb/articles/how-to-mask-the-effect-of-crazy-hot-pixel I have the coordinates of the pixels i'd like to mask. But
Metavision studio stops recording when I use reset signal on EVK3's TDRSTn pad
Hello, I'm following the procedure from the GENX320 datasheet for square light stimulation of the sensor for electro-optical caracterization : I generate a reset pulse on the EVK3's TDRSTn pad. When I start an acquisition, Metavision studio screen freezes
[SDK][ERROR] 0:1(10): error: GLSL ES 3.10 is not supported.
I am trying to run the metavision_sparse_optical_flow.py example script in linux on a .raw file I have collected. When I try to run the example, I get the following error messages. Online I found a recommendation to use "export MESA_GL_VERSION_OVERRIDE=3.3"
Error reading an HDF5 in python (MacOS)
When trying to read an HDF5 (converted from a RAW recording) using the h5py library I have the following error: OSError: Can't read data (required filter 'HDF ECF filter; see http://www.hdfgroup.org/services/contributions.html' is not registered) Here
What are the voltages in the LPF and HPF exactly indicating?
Hello and good day, For Gen3.1 sensors I know that the high-pass and low-pass filters' values are indicated in mV. This voltage is exactly from which part of the sensor and changing them makes what changes in the circuit? Is there a schematic diagram
EVT2.1 format
Hello, I'm trying to understand how the EVT 2.1 format works on GENX320. In order to do so, I generated 2 light edges (positive then negative) with a contrast well above the threshold value. The generated .RAW file should contain data with a sequence
Why use a lifo ?
Hello, I was curious to know why there was a lifo on the GENX320 sensor. Is its purpose purely for calibration and sensor caracterization (like QE), or does it have other useful applications ? I can't seem to find extensive information on this subject
Convert RAW files to DAT files in batches
Hello， I want to know how to convert RAW files to DAT files in batches. For example, there are 20 RAW files in a folder, it is too cumbersome to use the "metavision_file_to_dat.exe" to process them one by one. Thanks.
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)
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
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
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
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
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
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
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
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.
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
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
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
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