RecData

typedef struct RecData_tag {
  ReInit init;
  ReParm parm;
  ReImage image;
  long  image_top;
  long  image_bottom;
  long  busy;
  INT_PTR hWND_rec_finished;
  long  left, top;
  long  width, height;
  long  result_flags;
  void  *result_image;
  long  result_width;
  long  result_height;
  long  projection[2];
  short italic, bold;
  short strokelen, black;
  short  rec_wchar[REC_ALT][REC_WCHAR_COUNT];
  unsigned char rec_value[REC_ALT];
  long rec_top[REC_ALT]; 
  long rec_bottom[REC_ALT];
} RecData;

Elements:

init

Data for classifier initialisation. It must be set before rec_init().

parm

REC can be performed with many parameters. These parameters are included in the structure ReParm.

image

In this structure ReImage the image for processing and/or recognition will be expected or provided.

image_top, image_bottom

As image_top and image_bottom the upper and lower border of the character(s) can be specified, based on the scale given by base_line. For base_line=64 typical values for single characters are:
Zeichenposition

- A image_top=0, image_bottom=64, - Ü image_top=-16, image_bottom=64
- a image_top=14, image_bottom=64, - g image_top=14, image_bottom=82

If no values are specified here, the REC module keeps all alternative results. The module REL tries to find the top and bottom line by evaluating the position of accurate recognition results. This information is used to exclude alternatives that don't fit into the detected line structure. For finer control of this evaluation and the related exclusion of alternatives, the macros POS_NOliNECONTEXT, POS_SOFTliNECONTEXT, and POS_HARdlINECONTEXT in the parameter pos can be used.

busy

This value indicates whether recognition is in process (1) or completed (0). This is particularly important for parallel processing.

hWND_rec_finished

This parameter is relevant for Windows only. If provided, the module rec_do() will send messages to that window, which is described as handle by this value. As soon as the preprocessing of the image has been finished, rec_do() will perform the following call:

SendMessage((HWND) rec->hWND_rec_finished, WM_USER, (WPARAM)(REC_MESSAGE | REX_IMGREADY), (LPARAM) rec);

This gives the possibility to retrieve the result of the preprocessing (rec->image) before recognition. The pointer image will be set to the internal preprocessed image for this call. As soon as the recognition of a character is finished, rec_do() will perform the following call:

SendMessage((HWND) rec->hWND_rec_finished, WM_USER, (WPARAM)(REC_MESSAGE | REX_FINISHED), (LPARAM) rec);

In case of an error wParm contains also the bit REX_ERROR.

left, top

Position of the character after noise reduction.

width, height

Height and width of the character after noise reduction.

result_flags

The data element result_flags is set with RESULT_FLAG_RESPELL whenever the related result is approved by a dictionary lookup (RESPELL).

RESULT_FLAG_RESPELL_CONFIRMED: wird gesetzt wenn durch RESPELL bestätigt wurde.
RESULT_FLAG_RESPELL_GENERATED: wird gesetzt wenn durch RESPELL generiert wurde.
RESULT_FLAG_RESPELL: zur Abfrage ob RESULT_FLAG_RESPELL_CONFIRMED oder
RESULT_FLAG_RESPELL_GENERATED gesetzt wurden.

result_image

If TYPO_KEEPIMG is set at the parameter parm.typograph, the segmented characters are provided as images. The required memory is allocated and controlled from the REL module but can be freed directly with the function rel_freeimages(). Images are stored line by line, starting with the top line first. The lines are stored pixel by pixel, the most left pixel is stored first, and each pixel is represented as one byte. result_height contains the number of lines, result_width the number of columns of the image. Prior to result_image the related surrounding rectangle is found in the data structures RecData and RelResult. This describes the position of the images within the supplied original image. Please consider that the dimensions of the surrounding rectangle and the image dimensions are not always the same. Large images are compressed by the REL module and extraction is made from this compressed data.

result_width, result_height

Height and width of result_image (can be compressed).

projection[2]

Projection according to the mean slant of the characters of the line from the start and the end of the character onto the baseline.

italic, bold

Slant of characters (italic).
Schräglage

These items are set the detected slant and stroke width of the given character. It is not easy to define the slant of a character. We take two horizontal tangents of the character, one at the top and one at the bottom, connect the upper and the lower mean touching points. The slant of this line defines the slant of the character. One should take into consideration that several characters like L or k have a negative slant, i.e. to the left. For characters with a large horizontal extension like '-', determining the slant does not make sense. Let us describe the value italic of a character by construction:

normierte Zeilenhöhe mit 64 Pixel
Schräglage

Take a vertical line and rotate it around its middle point in the given slant. Assume a normalized line height of 64 pixels. Now measure the distance between the intersections of the vertical and the rotated line at the upper line boundary. This value, measured in units of pixel width, is delivered under italic. This definition has an advantage against measurement in degrees: the value can directly be used for slant correction by horizontal shifts. Under bold the mean stroke width of the character is delivered. It is measured in units of half pixel width. A value of 3 describes a stroke width of 1.5 pixel.

strokelen, black

strokelen returns the sum of the length of all strokes in the character image. Multiplication with the mean stroke width bold provides a rough approximation for the (double) number of black pixels in the image. A more precise value is given under black - the percentage of black pixels in the image (100*black_points/image_points).

rec_wchar

Depending on the set code page, under rec_wchar, the 2-byte identifier for the associated character is returned, the result of te recognition. The first character is generally the associated UTF_16 code and the second characterizes form classes. For example, for a normal handwriting zero the label 0_ will be delivered and for handwriting zero with a slash the label 0W. If the result of the detection is not unique, then up to 8 alternatives are returned in order of decreasing security. An empty or blanked string means "no result" or "no other alternatives". An overview of the labels and form classes available in KADMOS with their 2-byte labels is be found on our website.

rec_value

For each recognized character (and for all alternatives in ambiguous cases) the confidence of recognition is returned here. One means highest confidence, values above 128 mean least confidence.

rec_top, rec_bottom

All recognized alternatives are returned with information where their correct position should be in the current line. The values are scaled analogous to image_top and image_bottom, based on the specified base_line. For a non-specified base_line, a base_line = 64 is assumed.

RecData

Elements:

Reference: