Inspired by the QQE’s volatility filter, this filter applies the process directly to price rather than to a smoothed RSI.

This is an experimental study designed to filter out minor price action for a clearer view of trends.

First, a smooth average price range is calculated for the basis of the filter and multiplied by a specified amount.
Next, the filter is calculated by gating price movements that do not exceed the specified range.
Lastly the target ranges are plotted to display the prices that will trigger filter movement.

Custom bar colors are included. The color scheme is based on the filtered price trend.

Select the type you want to use via the “Filter Type” input. Type 1 is the original formula.
Multiple range sizing methods are available. You can choose from the following scales:

1. Points
2. Pips (Works best with forex pairs, obviously)3
3. Ticks4
4. % of Price
5. ATR
6. Average Change (Default. This is the original sizing method.)
7. Standard Deviation

Range smoothing is optional, and you can specify your smoothing length. Smoothing only affects dynamic scales (ATR, Average Change, and Standard Deviation).
Filter movement can be determined using wicks or close. This can be specified via the “Movement Source” input.

(description from the original author of this indicator: Donowan Wall, all credits go to him).

//PRC_Range Filter | indicator
//06.10.2020
//Nicolas @ www.prorealcode.com
//Sharing ProRealTime knowledge

// --- settings
ftype = 1 //Filter Type (1 or 2?)
rngqty   = 2.618 //Range Size
rngscale = 6 //Range Scale (1=Points, 2=Pips, 3=Ticks, 4=% of Price, 5=ATR, 6=Average Change, 7=Standard Deviation
rngper = 14 //Range Period (for ATR, Average Change, and Standard Deviation)
smoothrange = 1 //Smooth Range (0=false ; 1=true)
smoothper   = 27 //Smoothing Period
movsrc = 1  //Movement Source (0=Wicks, 1=Close)
//--- end of settings

once rngfilt=close
if barindex>max(rngper,smoothper) then
 //Range Size Function
 rngscale=max(1,min(rngscale,7))
 if rngscale=1 then
  scale = rngqty*pointsize
 elsif rngscale=2 then
  scale = rngqty*.0001
 elsif rngscale=3 then
  scale = rngqty*ticksize
 elsif rngscale=4 then
  scale = close*rngqty/100
 elsif rngscale=5 then
  scale = rngqty*average[rngper,1](tr)
 elsif rngscale=6 then
  scale = rngqty*average[rngper,1](abs(close-close[1]))
 elsif rngscale=7 then
  scale = STD[rngper](close)
 endif

 if smoothrange then
  r=average[smoothper,1](scale)
 else
  r=scale
 endif

 hh=close
 ll=close
 if movsrc<>1 then
  hh=high
  ll=low
 endif
  if ftype=1 then
   if hh>rngfilt[1] then
    if (hh-r)<rngfilt[1] then
     rngfilt=rngfilt[1]
    else
     rngfilt=hh-r
    endif
  elsif (ll+r)>rngfilt[1] then
   rngfilt=rngfilt[1]
  else
   rngfilt=ll+r
  endif
 else //ftype<>1
  if hh>=rngfilt[1]+r then
   rngfilt=(rngfilt[1]) + floor(abs(hh - (rngfilt[1]))/r)*r
  elsif ll<=rngfilt[1]-r then
   rngfilt=(rngfilt[1]) - floor(abs(ll - (rngfilt[1]))/r)*r
 else
  rngfilt=rngfilt[1]
 endif
endif

hiband    = rngfilt + r
loband    = rngfilt - r

if rngfilt>rngfilt[1] then
 upward=1
 downward=0
endif
if rngfilt<rngfilt[1] then
 upward=0
 downward=1
endif

 //Direction Conditions & colors
 if upward then
  cr=5
  cg=255
  cb=155
 endif
 if downward then
  cr=255
  cg=5
  cb=131
 endif

 if (close > rngfilt) and (close > (close[1])) and (upward > 0) then
  br=5
  bg=255
  bb=155
  //#05ff9b
 elsif (close > rngfilt) and (close <= (close[1])) and (upward > 0) then
  br=0
  bg=179
  bb=107
  //#00b36b
 elsif (close < rngfilt) and (close < (close[1])) and (downward > 0) then
  br=255
  bg=5
  bb=131
  //#ff0583
 elsif (close < rngfilt) and (close >= (close[1])) and (downward > 0) then
  br=184
  bg=0
  bb=93
  //#b8005d
 else
  br=204
  bg=204
  bb=204
 endif
 drawcandle(open,high,low,close) coloured(br,bg,bb) bordercolor(0,0,0)

 //Band Fills
 drawtriangle(barindex[1],hiband[1],barindex,rngfilt,barindex[0],hiband[0]) coloured(0,179,107,85) bordercolor(0,179,107,0)
 drawtriangle(barindex[1],hiband[1],barindex[1],rngfilt[1],barindex[0],rngfilt[0]) coloured(0,179,107,85) bordercolor(0,179,107,0)
 drawtriangle(barindex[1],loband[1],barindex,rngfilt,barindex[0],loband[0]) coloured(184,0,93,85) bordercolor(184,0,93,0)
 drawtriangle(barindex[1],loband[1],barindex[1],rngfilt[1],barindex[0],rngfilt[0]) coloured(184,0,93,85) bordercolor(184,0,93,0)
endif


return rngfilt coloured(cr,cg,cb) style(line,3) as "Filter"