Mlx90640 infrared thermal imager temperature measurement module development notes (4)

MLX90640 Infrared thermal imager temperature measurement module development notes （ Four ） Handling of damaged and bad pixels  
As before “ Development Notes （ One ）” said ,MLX90640 There may be no more than 4 Damaged pixels or bad pixels , After the temperature calculation process is completed , These bad pixels will get wrong temperature data , For dealing with these bad data MLX The recommended methods and specific functions are also given .（ In fact, it is to find the adjacent normal temperature data and take the average to replace the bad data ） 
 

 

Previous development notes （ One ） In the content of API library , There is no processing function for bad pixels , Add... Here . 
int CheckAdjacentPixels(uint16_t pix1, uint16_t pix2)
{
int pixPosDif;

pixPosDif = pix1 - pix2;
if(pixPosDif > -34 && pixPosDif < -30)
{
return -6;
}
if(pixPosDif > -2 && pixPosDif < 2)
{
return -6;
}
if(pixPosDif > 30 && pixPosDif < 34)
{
return -6;
}

return 0;
}

float GetMedian(float *values, int n)
{
float temp;

for(int i=0; i<n-1; i++)
{
for(int j=i+1; j<n; j++)
{
if(values[j] < values[i])
{
temp = values[i]; values[i] = values[j]; values[j] = temp;

}
}

if(n%2==0)
{
return ((values[n/2] + values[n/2 - 1]) / 2.0);

 
}
else
{

}
 

return values[n/2];
 

}

int IsPixelBad(uint16_t pixel,paramsMLX90640 *params)
{
for(int i=0; i<5; i++)
{
if(pixel == params->outlierPixels[i] || pixel == params->brokenPixels[i])
{
return 1;
}
}

return 0;
}
void MLX90640_BadPixelsCorrection(uint16_t *pixels, float *to, int mode, paramsMLX90640
*params)
{
float ap[4]; uint8_t pix; uint8_t line; uint8_t column;

pix = 0;
while(pixels[pix] != 0xFFFF)
{
line = pixels[pix]>>5;
column = pixels[pix] - (line<<5);

if(mode == 1)
{
if(line == 0)
{
if(column == 0)
{
to[pixels[pix]] = to[33];
}
else if(column == 31)
{
 

}
else
{

}
}
 
to[pixels[pix]] = to[62];

to[pixels[pix]] = (to[pixels[pix]+31] + to[pixels[pix]+33])/2.0;
 
else if(line == 23)
{
if(column == 0)
{
to[pixels[pix]] = to[705];
}
else if(column == 31)
{
 

}
else
{

}
}
 
to[pixels[pix]] = to[734];

to[pixels[pix]] = (to[pixels[pix]-33] + to[pixels[pix]-31])/2.0;
 
else if(column == 0)
{
to[pixels[pix]] = (to[pixels[pix]-31] + to[pixels[pix]+33])/2.0;
}
else if(column == 31)
{
 

}
else
{
 
to[pixels[pix]] = (to[pixels[pix]-33] + to[pixels[pix]+31])/2.0;

ap[0] = to[pixels[pix]-33];
ap[1] = to[pixels[pix]-31]; ap[2] = to[pixels[pix]+31]; ap[3] = to[pixels[pix]+33];
to[pixels[pix]] = GetMedian(ap,4);

}
else
{
 
}

if(column == 0)
{
 
to[pixels[pix]] = to[pixels[pix]+1];
}
else if(column == 1 || column == 30)
{
to[pixels[pix]] = (to[pixels[pix]-1]+to[pixels[pix]+1])/2.0;
}
else if(column == 31)
{
 

}
else
{

0)
 
to[pixels[pix]] = to[pixels[pix]-1];

if(IsPixelBad(pixels[pix]-2,params) == 0 && IsPixelBad(pixels[pix]+2,params) ==

{
ap[0] = to[pixels[pix]+1] - to[pixels[pix]+2]; ap[1] = to[pixels[pix]-1] - to[pixels[pix]-2];
if(fabs(ap[0]) > fabs(ap[1]))
{
 

}
else
{
 

}
else
{

}
 
to[pixels[pix]] = to[pixels[pix]-1] + ap[1];

to[pixels[pix]] = to[pixels[pix]+1] + ap[0];
 
to[pixels[pix]] = (to[pixels[pix]-1]+to[pixels[pix]+1])/2.0;
}
}
}
pix = pix + 1;
}
}
It's easy to use , In Development Notes （ 3、 ... and ）MLX90640_CalculateTo(Frame, MLXPars, 0.95, Tr, Temp); Then add two lines . as follows （ Italics are additions ）：
……
MLX90640_CalculateTo(Frame, MLXPars, 0.95, Tr, Temp); MLX90640_BadPixelsCorrection(MLXPars.brokenPixels, Temp, 1, MLXPars); MLX90640_BadPixelsCorrection(MLXPars.outlierPixels, Temp, 1, MLXPars);
……
/*
After the above treatment ,Temp The damaged and bad pixels in have been handled ,Temp The array contains the processed
768 A temperature value .
*/