get_1d_bar_code

get_1d_bar_code_scanline ( BarCodeRegion : : BarCodeDescr, GenericName, GenericValue, Orientation, StopIfFound : BarCodeElements, ScanlineNumPoints, ScanlineDecoded, ScanlinePointsRow, ScanlinePointsColumn )

Extract the widths of the elements inside a bar code region.

Like get_1d_bar_code, get_1d_bar_code_scanline extracts the widths of the elements of a bar code inside the specified region, but get_1d_bar_code_scanline also returns information about the used scanlines.

For a description of the parameters see get_1d_bar_code and find_1d_bar_code_scanline.

Parameters

`BarCodeRegion` (input_object)	image `->` object : byte / uint2
Region of bar code.

`BarCodeDescr` (input_control)	barcode_1d-array `->` string / integer / real
Description of a bar code class.

`GenericName` (input_control)	string(-array) `->` string
Names of optional parameters.
Default value: '[]'
List of values: 'sigma_project', 'amplitude_project', 'width_project', 'add_length_project', 'interpolation_project', 'num_scanlines', 'max_extra_elements'

`GenericValue` (input_control)	number(-array) `->` real / integer
Values of optional parameters.
Default value: '[]'

`Orientation` (input_control)	angle.rad `->` real
Orientation of bar code.

`StopIfFound` (input_control)	string `->` string
Leave operator as soon as the bar code has been decoded?.
Default value: 'false'
List of values: 'true', 'false'

`BarCodeElements` (output_control)	number-array `->` real
Widths of elements.

`ScanlineNumPoints` (output_control)	number(-array) `->` integer
Number of points belonging to that scanline.

`ScanlineDecoded` (output_control)	integer(-array) `->` integer
Information whether the bar code could be decoded with that scanline.
List of values: 0, 1, 2

`ScanlinePointsRow` (output_control)	real(-array) `->` real
Row - coordinates of the the points of the scanline.

`ScanlinePointsColumn` (output_control)	real(-array) `->` real
Column - coordinates of the the points of the scanline.

Example (Syntax: C++)

HTuple   empty;   // empty list of values
HTuple   BarCodeDescr;
HTuple   Orientations, Elements;
HTuple   Characters,Reference,IsCorrect;
Hobject  Image,CodeRegions,CodeRegion,GrayRegion;
long     num;
HTuple   ScanlineNumPoints, ScanlineDecoded, ScanlinePointsRow, 
         ScanlinePointsColumn;
HTuple   NumScanlines, NumPoints;
HTuple   j, k, indexPoint, nStart, nEnd;
HTuple   WindowHandle;  

gen_1d_bar_code_descr("code 39",4,15,&BarCodeDescr);
find_1d_bar_code_region(Image,&CodeRegion,BarCodeDescr,empty,empty,
                        &Orientations);
count_obj(CodeRegions,&num);
for (long i=0; i<num; i++)
{
  select_obj(CodeRegions,&CodeRegion,i);
  reduce_domain(Image,CodeRegion,GrayRegion)\:
  get_1d_bar_code_scanlines(GrayRegion,BarCodeDescr,empty,empty,
                  Orientations[i],"false", &Elements, &ScanlineNumPoints,
                  &ScanlineDecoded,&ScanlinePointsRow,&ScanlinePointsColumn);
  decode_1d_bar_code(Elements,BarCodeDescr,
                     &Characters,&Reference,&IsCorrect);
  // display scanlines
  NumScanlines = ScanlineNum.Num();
  indexPoint = HTuple(0);
  for (j=0; j<=NumScanlines-1; j+=1)
  {
    if (HTuple(ScanlineDecoded[(long)(j)[0]])==1)
    {
      set_color(WindowHandle,HTuple("green"));
    }
    else
    {
      set_color(WindowHandle,HTuple("red"));
    }
    NumPoints = HTuple(ScanlineNumPoints[(long)(j)[0]]);
    nStart = indexPoint;
    nEnd = (indexPoint+NumPoints)-1;
    for (k=nStart; k<=nEnd; k+=1)
    {
      disp_circle(WindowHandle,HTuple(ScanlinePointsRow[(long)(k)[0]]),
      HTuple(ScanlinePointsColumn[(long)(k)[0]]),HTuple(1));
    }
    indexPoint = nEnd+1;
  }
}

Result

The operator get_1d_bar_code returns the value 2 (H_MSG_TRUE) if the parameters are correct.

Parallelization Information

get_1d_bar_code_scanline is reentrant and processed without parallelization.

Possible Predecessors

find_1d_bar_code_region, select_obj, reduce_domain

Possible Successors

decode_1d_bar_code

Alternatives

find_1d_bar_code

Module

Bar Code