EXTRACT_DATA

Describe EXTRACT_DATA_PIC here.

      SUBROUTINE EXTRACT_DATA_PIC(NTMP,QSZ,SCALE,PICNM,IPL,
     .                     V,UX,UY,UZ,HUSE,HT,CP,SP,EUSE,ETOL,
     .                     FINV,DPIC_DLOC,DIDH,DJDH,Z0,KK,ESZ,DN, DNX)

INTEGER NTMP
- NTMP is a global compile parameter that defines the maximum size of maplets (it allocates memory)
  - Standard value is 128
INTEGER QSZ
- QSZ is the half size of maplet. width = QSZ * 2 + 1
  - It is derived from READ_MAP
DOUBLE PRECISION SCALE
- The scale (both horizontally x and y, as well as verticlally). The values in the MAPLET should be multiplied by this value to get its actual value. Units are in km.
  - It is derived from READ_MAP
CHARACTER*12 PICNM
- The name of the image that you want to use. The file is read in (again) in this program)
DOUBLE PRECISION IPL(2)
- IPL = Image Pixel Line. Scaling factor to translate from physical to image frame.
  - Comes from V2IMGPLV
DOUBLE PRECISION V(3)
- Central vector of the maplet
  - It is derived from READ_MAP
DOUBLE PRECISION UX(3)
DOUBLE PRECISION UY(3)
DOUBLE PRECISION UZ(3)
- Normal plane of the maplet in X, Y and Z space
  - It is derived from READ_MAP
LOGICAL HUSE(-NTMP:NTMP,-NTMP:NTMP)
- Tracks each pixel of the maplet to define if its value should be considered
  - Defined in HGT2SLP
REAL*4 HT(-NTMP:NTMP,-NTMP:NTMP)
- HT - Height. The height of the template at that location of the maplet. Used for trying to identifing shadow.
DOUBLE PRECISION CP(3)
- Camera vector
  - Calculated in this subroutine
DOUBLE PRECISION SP(3)
- Sun vector
  - Calculated in this subroutine
LOGICAL EUSE
- "Expanded T1" Flag for when to use the expanded threshold for DN.
  Is a flag set within lithos or lithosp using the 'x' option
  - Uses the ETOL variable
DOUBLE PRECISION ETOL
- Expanded T1 flag variable.
  Is a flag set within lithos or lithosp using the 'x' option
  - Typically set to .025 (standard within the scripts for LITHOSP)
DOUBLE PRECISION FINV
- Reports the fraction of invisible pixels within the maplet/image intersection
DOUBLE PRECISION DPIC_DLOC(2,3)
- This subroutine computes the change in the image-space location (p,l) of a point (x,y,z) on a maplet as the point is moved in the maplet frame.
  - Changed within LOC2PIX that is typically called from this subroutine.
DOUBLE PRECISION DIDH
DOUBLE PRECISION DJDH
- Rate of change for the position I and J in the picture
  - Calcualted in this routine and reported back to who called it
INTEGER Z0(2)
- Center point to extract the data from the image.
  - Defined in lithos and derived from IPL. Used in PICINPT and BRT1
INTEGER KK, ESZ
- KK is a spacing parameter, which I think is based upon the maplet.
- ESZ is the size of the array.
  - Defined in lithos. Used in PICINPT and BRT1
INTEGER DN(-1300:1300,-1300:1300)
- The workspace of displayed DN for both the image and the maplet (template)
  - Set in this subroutine.
REAL*4 DNX(-NTMP:NTMP,-NTMP:NTMP)
- The filled out data that we really want. Set in this routine.

categorySubroutine

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