/****************************************************************************** ** Filename: mfoutline.c ** Purpose: Interface to outline struct used for extracting features ** Author: Dan Johnson ** History: Thu May 17 08:14:18 1990, DSJ, Created. ** ** (c) Copyright Hewlett-Packard Company, 1988. ** Licensed under the Apache License, Version 2.0 (the "License"); ** you may not use this file except in compliance with the License. ** You may obtain a copy of the License at ** http://www.apache.org/licenses/LICENSE-2.0 ** Unless required by applicable law or agreed to in writing, software ** distributed under the License is distributed on an "AS IS" BASIS, ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ** See the License for the specific language governing permissions and ** limitations under the License. ******************************************************************************/ /*---------------------------------------------------------------------------- Include Files and Type Defines ----------------------------------------------------------------------------*/ #include "clusttool.h" //If remove you get cought in a loop somewhere #include "emalloc.h" #include "mfoutline.h" #include "blobs.h" #include "const.h" #include "mfx.h" #include "params.h" #include "classify.h" #include #include /*---------------------------------------------------------------------------- Public Code ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/ /** Convert a blob into a list of MFOUTLINEs (float-based microfeature format). */ LIST ConvertBlob(TBLOB *blob) { LIST outlines = NIL_LIST; return (blob == NULL) ? NIL_LIST : ConvertOutlines(blob->outlines, outlines, outer); } /*---------------------------------------------------------------------------*/ /** Convert a TESSLINE into the float-based MFOUTLINE micro-feature format. */ MFOUTLINE ConvertOutline(TESSLINE *outline) { MFEDGEPT *NewPoint; MFOUTLINE MFOutline = NIL_LIST; EDGEPT *EdgePoint; EDGEPT *StartPoint; EDGEPT *NextPoint; if (outline == NULL || outline->loop == NULL) return MFOutline; StartPoint = outline->loop; EdgePoint = StartPoint; do { NextPoint = EdgePoint->next; /* filter out duplicate points */ if (EdgePoint->pos.x != NextPoint->pos.x || EdgePoint->pos.y != NextPoint->pos.y) { NewPoint = NewEdgePoint(); ClearMark(NewPoint); NewPoint->Hidden = EdgePoint->IsHidden(); NewPoint->Point.x = EdgePoint->pos.x; NewPoint->Point.y = EdgePoint->pos.y; MFOutline = push(MFOutline, NewPoint); } EdgePoint = NextPoint; } while (EdgePoint != StartPoint); if (MFOutline != NULL) MakeOutlineCircular(MFOutline); return MFOutline; } /*---------------------------------------------------------------------------*/ /** * Convert a tree of outlines to a list of MFOUTLINEs (lists of MFEDGEPTs). * * @param outline first outline to be converted * @param mf_outlines list to add converted outlines to * @param outline_type are the outlines outer or holes? */ LIST ConvertOutlines(TESSLINE *outline, LIST mf_outlines, OUTLINETYPE outline_type) { MFOUTLINE mf_outline; while (outline != NULL) { mf_outline = ConvertOutline(outline); if (mf_outline != NULL) mf_outlines = push(mf_outlines, mf_outline); outline = outline->next; } return mf_outlines; } /*---------------------------------------------------------------------------*/ /** * This routine searches thru the specified outline, computes * a slope for each vector in the outline, and marks each * vector as having one of the following directions: * N, S, E, W, NE, NW, SE, SW * This information is then stored in the outline and the * outline is returned. * @param Outline micro-feature outline to analyze * @param MinSlope controls "snapping" of segments to horizontal * @param MaxSlope controls "snapping" of segments to vertical * @return none * @note Exceptions: none * @note History: 7/21/89, DSJ, Created. */ void FindDirectionChanges(MFOUTLINE Outline, FLOAT32 MinSlope, FLOAT32 MaxSlope) { MFEDGEPT *Current; MFEDGEPT *Last; MFOUTLINE EdgePoint; if (DegenerateOutline (Outline)) return; Last = PointAt (Outline); Outline = NextPointAfter (Outline); EdgePoint = Outline; do { Current = PointAt (EdgePoint); ComputeDirection(Last, Current, MinSlope, MaxSlope); Last = Current; EdgePoint = NextPointAfter (EdgePoint); } while (EdgePoint != Outline); } /* FindDirectionChanges */ /*---------------------------------------------------------------------------*/ /** * This routine deallocates all of the memory consumed by * a micro-feature outline. * @param arg micro-feature outline to be freed * @return none * @note Exceptions: none * @note History: 7/27/89, DSJ, Created. */ void FreeMFOutline(void *arg) { //MFOUTLINE Outline) MFOUTLINE Start; MFOUTLINE Outline = (MFOUTLINE) arg; /* break the circular outline so we can use std. techniques to deallocate */ Start = list_rest (Outline); set_rest(Outline, NIL_LIST); while (Start != NULL) { free_struct (first_node (Start), sizeof (MFEDGEPT), "MFEDGEPT"); Start = pop (Start); } } /* FreeMFOutline */ /*---------------------------------------------------------------------------*/ /** * Release all memory consumed by the specified list * of outlines. * @param Outlines list of mf-outlines to be freed * @return none * @note Exceptions: none * @note History: Thu Dec 13 16:14:50 1990, DSJ, Created. */ void FreeOutlines(LIST Outlines) { destroy_nodes(Outlines, FreeMFOutline); } /* FreeOutlines */ /*---------------------------------------------------------------------------*/ /** * This routine searches thru the specified outline and finds * the points at which the outline changes direction. These * points are then marked as "extremities". This routine is * used as an alternative to FindExtremities(). It forces the * endpoints of the microfeatures to be at the direction * changes rather than at the midpoint between direction * changes. * @param Outline micro-feature outline to analyze * @return none * @note Globals: none * @note Exceptions: none * @note History: 6/29/90, DSJ, Created. */ void MarkDirectionChanges(MFOUTLINE Outline) { MFOUTLINE Current; MFOUTLINE Last; MFOUTLINE First; if (DegenerateOutline (Outline)) return; First = NextDirectionChange (Outline); Last = First; do { Current = NextDirectionChange (Last); MarkPoint (PointAt (Current)); Last = Current; } while (Last != First); } /* MarkDirectionChanges */ /*---------------------------------------------------------------------------*/ /** Return a new edge point for a micro-feature outline. */ MFEDGEPT *NewEdgePoint() { return ((MFEDGEPT *) alloc_struct(sizeof(MFEDGEPT), "MFEDGEPT")); } /*---------------------------------------------------------------------------*/ /** * This routine returns the next point in the micro-feature * outline that is an extremity. The search starts after * EdgePoint. The routine assumes that the outline being * searched is not a degenerate outline (i.e. it must have * 2 or more edge points). * @param EdgePoint start search from this point * @return Next extremity in the outline after EdgePoint. * @note Globals: none * @note Exceptions: none * @note History: 7/26/89, DSJ, Created. */ MFOUTLINE NextExtremity(MFOUTLINE EdgePoint) { EdgePoint = NextPointAfter(EdgePoint); while (!PointAt(EdgePoint)->ExtremityMark) EdgePoint = NextPointAfter(EdgePoint); return (EdgePoint); } /* NextExtremity */ /*---------------------------------------------------------------------------*/ /** * This routine normalizes the coordinates of the specified * outline so that the outline is deskewed down to the * baseline, translated so that x=0 is at XOrigin, and scaled * so that the height of a character cell from descender to * ascender is 1. Of this height, 0.25 is for the descender, * 0.25 for the ascender, and 0.5 for the x-height. The * y coordinate of the baseline is 0. * @param Outline outline to be normalized * @param XOrigin x-origin of text * @return none * @note Globals: none * @note Exceptions: none * @note History: 8/2/89, DSJ, Created. */ void NormalizeOutline(MFOUTLINE Outline, FLOAT32 XOrigin) { if (Outline == NIL_LIST) return; MFOUTLINE EdgePoint = Outline; do { MFEDGEPT *Current = PointAt(EdgePoint); Current->Point.y = MF_SCALE_FACTOR * (Current->Point.y - kBlnBaselineOffset); Current->Point.x = MF_SCALE_FACTOR * (Current->Point.x - XOrigin); EdgePoint = NextPointAfter(EdgePoint); } while (EdgePoint != Outline); } /* NormalizeOutline */ /*---------------------------------------------------------------------------*/ namespace tesseract { /** * This routine normalizes every outline in Outlines * according to the currently selected normalization method. * It also returns the scale factors that it used to do this * scaling. The scale factors returned represent the x and * y sizes in the normalized coordinate system that correspond * to 1 pixel in the original coordinate system. * * Globals: * - classify_norm_method method being used for normalization * - classify_char_norm_range map radius of gyration to this value * @param Outlines list of outlines to be normalized * @param XScale x-direction scale factor used by routine * @param YScale y-direction scale factor used by routine * @return none (Outlines are changed and XScale and YScale are updated) * @note Exceptions: none * @note History: Fri Dec 14 08:14:55 1990, DSJ, Created. */ void Classify::NormalizeOutlines(LIST Outlines, FLOAT32 *XScale, FLOAT32 *YScale) { MFOUTLINE Outline; switch (classify_norm_method) { case character: ASSERT_HOST(!"How did NormalizeOutlines get called in character mode?"); break; case baseline: iterate(Outlines) { Outline = (MFOUTLINE) first_node(Outlines); NormalizeOutline(Outline, 0.0); } *XScale = *YScale = MF_SCALE_FACTOR; break; } } /* NormalizeOutlines */ } // namespace tesseract /*---------------------------------------------------------------------------- Private Code ----------------------------------------------------------------------------*/ /** * Change the direction of every vector in the specified * outline segment to Direction. The segment to be changed * starts at Start and ends at End. Note that the previous * direction of End must also be changed to reflect the * change in direction of the point before it. * @param Start, End defines segment of outline to be modified * @param Direction new direction to assign to segment * @return none * @note Globals: none * @note Exceptions: none * @note History: Fri May 4 10:42:04 1990, DSJ, Created. */ void ChangeDirection(MFOUTLINE Start, MFOUTLINE End, DIRECTION Direction) { MFOUTLINE Current; for (Current = Start; Current != End; Current = NextPointAfter (Current)) PointAt (Current)->Direction = Direction; PointAt (End)->PreviousDirection = Direction; } /* ChangeDirection */ /** * This routine normalizes each point in Outline by * translating it to the specified center and scaling it * anisotropically according to the given scale factors. * @param Outline outline to be character normalized * @param cn_denorm * @return none * @note Globals: none * @note Exceptions: none * @note History: Fri Dec 14 10:27:11 1990, DSJ, Created. */ void CharNormalizeOutline(MFOUTLINE Outline, const DENORM& cn_denorm) { MFOUTLINE First, Current; MFEDGEPT *CurrentPoint; if (Outline == NIL_LIST) return; First = Outline; Current = First; do { CurrentPoint = PointAt(Current); FCOORD pos(CurrentPoint->Point.x, CurrentPoint->Point.y); cn_denorm.LocalNormTransform(pos, &pos); CurrentPoint->Point.x = (pos.x() - MAX_UINT8 / 2) * MF_SCALE_FACTOR; CurrentPoint->Point.y = (pos.y() - MAX_UINT8 / 2) * MF_SCALE_FACTOR; Current = NextPointAfter(Current); } while (Current != First); } /* CharNormalizeOutline */ /** * This routine computes the slope from Start to Finish and * and then computes the approximate direction of the line * segment from Start to Finish. The direction is quantized * into 8 buckets: * N, S, E, W, NE, NW, SE, SW * Both the slope and the direction are then stored into * the appropriate fields of the Start edge point. The * direction is also stored into the PreviousDirection field * of the Finish edge point. * @param Start starting point to compute direction from * @param Finish finishing point to compute direction to * @param MinSlope slope below which lines are horizontal * @param MaxSlope slope above which lines are vertical * @return none * @note Globals: none * @note Exceptions: none * @note History: 7/25/89, DSJ, Created. */ void ComputeDirection(MFEDGEPT *Start, MFEDGEPT *Finish, FLOAT32 MinSlope, FLOAT32 MaxSlope) { FVECTOR Delta; Delta.x = Finish->Point.x - Start->Point.x; Delta.y = Finish->Point.y - Start->Point.y; if (Delta.x == 0) if (Delta.y < 0) { Start->Slope = -MAX_FLOAT32; Start->Direction = south; } else { Start->Slope = MAX_FLOAT32; Start->Direction = north; } else { Start->Slope = Delta.y / Delta.x; if (Delta.x > 0) if (Delta.y > 0) if (Start->Slope > MinSlope) if (Start->Slope < MaxSlope) Start->Direction = northeast; else Start->Direction = north; else Start->Direction = east; else if (Start->Slope < -MinSlope) if (Start->Slope > -MaxSlope) Start->Direction = southeast; else Start->Direction = south; else Start->Direction = east; else if (Delta.y > 0) if (Start->Slope < -MinSlope) if (Start->Slope > -MaxSlope) Start->Direction = northwest; else Start->Direction = north; else Start->Direction = west; else if (Start->Slope > MinSlope) if (Start->Slope < MaxSlope) Start->Direction = southwest; else Start->Direction = south; else Start->Direction = west; } Finish->PreviousDirection = Start->Direction; } /** * This routine returns the next point in the micro-feature * outline that has a direction different than EdgePoint. The * routine assumes that the outline being searched is not a * degenerate outline (i.e. it must have 2 or more edge points). * @param EdgePoint start search from this point * @return Point of next direction change in micro-feature outline. * @note Globals: none * @note Exceptions: none * @note History: 7/25/89, DSJ, Created. */ MFOUTLINE NextDirectionChange(MFOUTLINE EdgePoint) { DIRECTION InitialDirection; InitialDirection = PointAt (EdgePoint)->Direction; MFOUTLINE next_pt = NULL; do { EdgePoint = NextPointAfter(EdgePoint); next_pt = NextPointAfter(EdgePoint); } while (PointAt(EdgePoint)->Direction == InitialDirection && !PointAt(EdgePoint)->Hidden && next_pt != NULL && !PointAt(next_pt)->Hidden); return (EdgePoint); }