query_bar_code_params
— Get the names of the parameters that can be used in set_bar_code* and
get_bar_code* operators for a given bar code model
query_bar_code_params( : : BarCodeHandle, Properties : GenParamName)
The operator query_bar_code_params
returns parameter names
of the bar code model that correspond to the selection given in
Properties
. To explain this, here first some background:
After creating a bar code model, all parameters
are initially set 'general' , i.e., they have the same values set
for each supported bar code type. During automatic parameter training or
after calling the operator set_bar_code_param_specific
some
parameters might become bar code type specific at runtime. These parameters
can not be read with the general operator
get_bar_code_param
but must be read for a given bar code type with
get_bar_code_param_specific
. To make this access easy and generic,
the output GenParamName
of query_bar_code_params
can be
used as input parameter GenParamName
in
get_bar_code_param
or get_bar_code_param_specific
, depending
on Properties
='*general' or
Properties
='*specific' .
Please note that you could
alternatively use a static tuple of
parameter names for get_bar_code_param
or
get_bar_code_param_specific
(e.g. the parameter names described with
these operators), but this
is inflexible and therefore not recommended.
Possible values for Properties
are:
Returns the names of all parameters supported by the bar code
reader. The names are independent of the bar code model given
in BarCodeHandle
.
Returns the names of the parameters that contain the same values
for all supported bar code types, i.e., there are no specific values
set for certain bar code types, e.g., with
set_bar_code_param_specific
. The values of only these
parameters can be read with get_bar_code_param
.
Please note that the parameter name 'train' is explicitly excluded
here. 'train' in a following call to get_bar_code_param
would return a multivalue tuple and therefore couldn't be used
within one tuple in combination with other parameter names.
Returns the names of the parameters that contain specific values
for certain bar code types. The values of these parameters must
be read with get_bar_code_param_specific
instead of
get_bar_code_param
. Bar code type specific values can
occur in conjunction with bar code autodiscrimination, described
with the operator find_bar_code
or automatic parameter
training.
Returns the names of parameters that have already been trained
and contain the same values for all supported bar code types.
The training mode is described with the operator
set_bar_code_param
.
Returns the names of the parameters that have already been trained
and contain specific values for certain bar code types.
The training mode is described with the operator
set_bar_code_param
.
BarCodeHandle
(input_control) barcode →
(handle)
Handle of the bar code model.
Properties
(input_control) attribute.name →
(string)
Properties of the parameters.
Default value: 'trained_general'
List of values: 'all' , 'general' , 'specific' , 'trained_general' , 'trained_specific'
GenParamName
(output_control) attribute.name(-array) →
(string)
Names of the generic parameters.
TrainParams := ['element_size_min', 'element_size_max', 'orientation'] Train3times := gen_tuple_const(|TrainParams|,'train') create_bar_code_model (Train3times, TrainParams, BarCodeHandle) find_bar_code (Image, SymbolRegions, BarCodeHandle, 'EAN-13', \ DecodedDataStrings) query_bar_code_params (BarCodeHandle, 'trained_general', NamesGen) * returns NamesGen = ['element_size_max', 'element_size_min'] get_bar_code_param (BarCodeHandle, NamesGen, ValGen) * returns e.g. ValGen = [4.0, 1.5] query_bar_code_params (BarCodeHandle, 'trained_specific', NamesSpec) * returns NamesSpec = ['orientation', 'orientation_tol'] get_bar_code_param_specific (BarCodeHandle, 'EAN-13', NamesSpec, ValSpec) * returns e.g. ValSpec = [89.9127, 0.5]
The operator query_bar_code_params
returns the value 2 (H_MSG_TRUE) if the
given parameters are correct. Otherwise, an exception is raised.
find_bar_code
,
decode_bar_code_rectangle2
get_bar_code_param
,
get_bar_code_param_specific
Bar Code