# Questions tagged [conversion]

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34 questions
1answer
32 views

### Usefulness of Matched $z$ transform Method

I'm aware that the matched $z$ transform method maps between the continuous $s$ plane and the discrete/digital $z$ plane but my question is - when would this be necessary? Why would we need to convert ...
1answer
72 views

### Is possible to perform algebric operation with bitwise operations in PDM domain?

I have to compute the some operations (say sum and subtraction) between 2 signals. I have data in PDM domain: x1_pdm(t)=[0101011....]; and x2_pdm(t)=[0101011....]; What I do now is: convert x1_pdm and ...
1answer
26 views

### Why is the green colour not represented as black in Cr component of YCbCr?

I am testing conversion from RGB to YCbCr in Python's pillow imaging module (formerly PIL), and am getting predictable results ...
2answers
62 views

### Conversion from Floating point representation to Fixed point representation

I have written a matlab function for a constellation mapper and I want to create a Fixed-point version of that code for implementation on FPGA. I know matlab has a specific toolbox for fixed-point ...
2answers
969 views

### Pa^2/Hz to dB/Hz conversion

I have PSD data from an computational aeroacoustics analysis, which is in the units of Pa^2/Hz. I want to convert this to dB/hz; would it be correct if I use PSD[in dB/Hz] = 10log10(PSD[in Pa^2/Hz]) ...
1answer
34 views

### Conversion between DTFT in radians/sample to DTFT in cycles/sample

I have found that most commonly the DTFT is defined as: $X(\omega) = \sum_{n=-\infty}^{\infty} x[n]e^{-j \omega n}$. However the class I am taking frequently uses the DTFT expressed in "normalized ...
1answer
22 views

### Conversion of airflow signal into 1-D as a input for CNN [closed]

Trying to detect apnea from airflow signal. I have 100 files of the patient each file contains at least 8 hours of data and sampling rate is 32 Hz. How to prepare my dataset which is used as an input ...
1answer
53 views

### Fundemental scintific publication in up conversion down conversion

Prior to performing DSP on a signal and afterwards, up and down conversion of the same in order to transmit and receive the signal is important. I would like to know if anyone knows a fundamental ...
0answers
20 views

### What is the relationship between luminosity of Lab color space and intensity of HSI color space?

I am wondering whether one can simply convert the intensity of a color in HSI space to the luminosity value in Lab space. I am referring to te CIELab color space as discussed here: https://en....
3answers
309 views

### Going from digital to analog filters

I've been learning about digital signal processing for some time, and I understand the principles in the digital world, as well as the conversion of continuous filters in the s-domain to digital ...
0answers
74 views

### Calculating gyroscope data from accelerometer and attitude data

I am currently collecting accelerometer and attitude data using smartphone sensors. Data is collected at 100Hz over 2.5 seconds. Of which there are 250 accelerometer points and 250 points representing ...
1answer
9k views

### dB/hz to dB Conversion

I'm have a PSD graph of dB/hz vs. frequency in hz. I want to convert the dB/hz unit to dB, but I can't find any way of doing it. Help would be much appreciated!
1answer
47 views

### Why 1.01 equals -0.75 in Q2

I'm trying to learn Q notation but I don't understand why 1.01 in the Q2 number format equals -0.75. How is that calculation done? I can understand that 1.1 equals -0.5 because the leading 1 means the ...
1answer
905 views

### How to choose the most appropriate color space for a computer vision application?

A lot of image processing techniques used in computer vision consist (among other things) in switching from RGB to another color space (HSV, YUV, LMS...) : color transfer, visual tracking... It seems ...
1answer
113 views

### Non-uniform acquisition to fixed sample rate

I'm facing a challenge that requires me to process a signal from an engine knocking sensor. The acquisition is done synchronously with the engine speed (every 0.1 degree) which gives me a range from ...
1answer
1k views

### Convert 16-bit wav file to 12-bit raw audio file

I want to convert a 16-bit wav file to 12 bit raw audio samples (to simulate the output of an ADC). I'm trying to run ...
1answer
2k views

### conversion of 1d signal to 2d signal for CNN operation

I have a 1D signal data sampled at 25kHz and I want to modify in to 2D signal so as to modify it as the input to ConvolutionalNets as they work only on 2 dimensional data. What are possible ways to ...
1answer
146 views

### Proper rounding when converting between digitized values and floating point

I have some very large files that are unsigned 8 bit (0 to 255), real valued. I need to do some simple tuning and decimation. In the past, when I've dealt with low bit rate samples, I've run into ...
0answers
190 views

### I have 24-bit data in two's complement 32-bit integers. I need Q31 data

I have been trying to learn about Q31 format (as well as Q15), but I am having trouble understanding how it works. So my CODEC is giving me 24-bit two's complement data. I have converted this data ...
1answer
919 views

### Converting from radians/samples to normalized frequency range $[0.0, 1.0]$?

I'm trying to understand the following code, specifically how to use the results of scipy.signal.freqz where w in ...
2answers
2k views

### Conversion into the Q31 Format

I have a Setup, where I receive 24-bit ADC samples in the two's complement in 8-bit chunks. Usually I just "converted" them into a signed 32-bit integer like this: ...
3answers
134 views

### Linearizing digital-analog converters

I'm looking at ways to improve the effective resolution of DACs. It seems that element mismatch (i.e. integral non-linearity) is the main contributor to distortion in modern DACs. Apart from ...
4answers
5k views

### How to Generate False Color Palette

How to convert grayscale intensity input to something like the following image? It seems that no response (0, black) is converted to dark blue, then it goes through other colors to red. How are ...
2answers
1k views

### Convert sine wave signal to square wave signal

I have a signal containing a variation of digital ASK type on-off keyed sine wave among which some stochastic irrelevant harmonic waves occur, like you can see on this figure: In its current form ...
1answer
47 views

### Difference between delayed down-converted signal and a down-converted delayed signal

I am having trouble understand what I think should be a pretty simple concept. Conceptually I can understand that a signal that has been down-converted, and then delayed in time is different than a ...
2answers
439 views

### Grayscale conversion before applying sobel gradient operator

I am currently replacing a hand-made image processing library by OpenCV. The programmer who worked on this library had implemented the sobel gradient function. This implementation is right except that ...
1answer
2k views

### inverse Fixed point number (number^-1) [closed]

Could someone please provide a method for inverting random fixed point numbers. I have as an input both positive and negative floating point numbers that should be converted into fixed point and then ...
1answer
641 views

### Frequency domain to time domain conversion-(varying sample count)

I need to convert 150 Frequency domain samples to the time domain. The problem is, I have been provided with 250 time domain samples for comparing my results. How am I supposed to relate the 150 ...
3answers
200 views

### Low analog lowpass + ADC vs High analog lowpass + ADC + low digital lowpass

I'm doing EEG data collection and my amp forces use of an analog lowpass filter before the ADC. I'm fairly sure that I won't be interested in phenomena associated with frequencies of 30Hz or higher, ...
1answer
328 views

### DAC and sample and hold effect

I am having some trouble understanding how a digital signal gets converted back to an analog signal. Why is the "sample and hold" effect a problem?
1answer
127 views

### Revert anayltic signal(length(N/2)) to real signal (length(N))

As a beginner in signal processing, i'll try to explain my problem most thoroughly. I'll firstly explain the idea of the transformation the real valued data has undergone. This includes the ideas and ...
2answers
1k views

### 12 bit ADC to 8 bit DAC

A bit of background information: I plan to start experimenting with digital signal processing on microcontrollers. The particular microcontroller I plan to use (TI Stellaris LM4F230H5QR, from the ...
1answer
71 views

### Is gamma correction applied in my setup

I am working on a scientific application where I would like to evaluate luminance in an image, however I am unsure if what I receive from my setup is luminance (Y) or luma (Y'). I use a camera with a ...
1answer
487 views

### Is the mean of visible color in CIELab color space can be non visible color?

I am converting color from RGB to CIELab to train a GMM. When I get back the mean of clusters of the GMM I have sometimes negatives values in RGB space. I was wondering if the mean of only visible ...