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53fc4456cc
Eliminated the flexfx scheme for calling global feature extractor functions through an array of function pointers. Deleted dead code I found as a by-product. This CL does not change BlobToTrainingSample or ExtractFeatures to be full members of Classify (the eventual goal) as that would make it even bigger, since there are a lot of callers to these functions. When ExtractFeatures and BlobToTrainingSample are members of Classify they will be able to access control parameters in Classify, which will greatly simplify developing variations to the feature extraction process.
77 lines
3.1 KiB
C++
77 lines
3.1 KiB
C++
/******************************************************************************
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** Filename: normfeat.c
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** Purpose: Definition of char normalization features.
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** Author: Dan Johnson
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** History: 12/14/90, DSJ, Created.
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**
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** (c) Copyright Hewlett-Packard Company, 1988.
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** Licensed under the Apache License, Version 2.0 (the "License");
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** you may not use this file except in compliance with the License.
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** You may obtain a copy of the License at
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** http://www.apache.org/licenses/LICENSE-2.0
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** Unless required by applicable law or agreed to in writing, software
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** distributed under the License is distributed on an "AS IS" BASIS,
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** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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** See the License for the specific language governing permissions and
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** limitations under the License.
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******************************************************************************/
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/**----------------------------------------------------------------------------
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Include Files and Type Defines
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----------------------------------------------------------------------------**/
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#include "normfeat.h"
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#include "intfx.h"
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#include "featdefs.h"
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#include "mfoutline.h"
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/**----------------------------------------------------------------------------
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Public Code
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----------------------------------------------------------------------------**/
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// Return the length of the outline in baseline normalized form.
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FLOAT32 ActualOutlineLength(FEATURE Feature) {
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return (Feature->Params[CharNormLength] * LENGTH_COMPRESSION);
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}
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/*---------------------------------------------------------------------------*/
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// Return the character normalization feature for a blob.
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//
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// The features returned are in a scale where the x-height has been
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// normalized to live in the region y = [-0.25 .. 0.25]. Example ranges
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// for English below are based on the Linux font collection on 2009-12-04:
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//
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// Params[CharNormY]
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// The y coordinate of the grapheme's centroid.
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// English: [-0.27, 0.71]
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//
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// Params[CharNormLength]
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// The length of the grapheme's outline (tiny segments discarded),
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// divided by 10.0=LENGTH_COMPRESSION.
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// English: [0.16, 0.85]
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//
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// Params[CharNormRx]
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// The radius of gyration about the x axis, as measured from CharNormY.
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// English: [0.011, 0.34]
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//
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// Params[CharNormRy]
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// The radius of gyration about the y axis, as measured from
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// the x center of the grapheme's bounding box.
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// English: [0.011, 0.31]
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//
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FEATURE_SET ExtractCharNormFeatures(const INT_FX_RESULT_STRUCT& fx_info) {
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FEATURE_SET feature_set = NewFeatureSet(1);
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FEATURE feature = NewFeature(&CharNormDesc);
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feature->Params[CharNormY] =
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MF_SCALE_FACTOR * (fx_info.Ymean - kBlnBaselineOffset);
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feature->Params[CharNormLength] =
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MF_SCALE_FACTOR * fx_info.Length / LENGTH_COMPRESSION;
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feature->Params[CharNormRx] = MF_SCALE_FACTOR * fx_info.Rx;
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feature->Params[CharNormRy] = MF_SCALE_FACTOR * fx_info.Ry;
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AddFeature(feature_set, feature);
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return feature_set;
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} /* ExtractCharNormFeatures */
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