/****************************************************************************** ** 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 #define MIN_INERTIA (0.00001) /*---------------------------------------------------------------------------- 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). // // Parameters: // outline first outline to be converted // mf_outlines list to add converted outlines to // 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; } /*---------------------------------------------------------------------------*/ void ComputeOutlineStats(LIST Outlines, OUTLINE_STATS *OutlineStats) { /* ** Parameters: ** Outlines list of outlines to compute stats for ** OutlineStats place to put results ** Globals: none ** Operation: This routine computes several statistics about the outlines ** in Outlines. These statistics are usually used to perform ** anistropic normalization of all of the outlines. The ** statistics generated are: ** first moments about x and y axes ** total length of all outlines ** center of mass of all outlines ** second moments about center of mass axes ** radius of gyration about center of mass axes ** Return: none (results are returned in OutlineStats) ** Exceptions: none ** History: Fri Dec 14 08:32:03 1990, DSJ, Created. */ MFOUTLINE Outline; MFOUTLINE EdgePoint; MFEDGEPT *Current; MFEDGEPT *Last; InitOutlineStats(OutlineStats); iterate(Outlines) { Outline = (MFOUTLINE) first_node (Outlines); Last = PointAt (Outline); Outline = NextPointAfter (Outline); EdgePoint = Outline; do { Current = PointAt (EdgePoint); UpdateOutlineStats (OutlineStats, Last->Point.x, Last->Point.y, Current->Point.x, Current->Point.y); Last = Current; EdgePoint = NextPointAfter (EdgePoint); } while (EdgePoint != Outline); } FinishOutlineStats(OutlineStats); } /* ComputeOutlineStats */ /*---------------------------------------------------------------------------*/ void FindDirectionChanges(MFOUTLINE Outline, FLOAT32 MinSlope, FLOAT32 MaxSlope) { /* ** Parameters: ** Outline micro-feature outline to analyze ** MinSlope controls "snapping" of segments to horizontal ** MaxSlope controls "snapping" of segments to vertical ** Globals: none ** Operation: ** 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. ** Return: none ** Exceptions: none ** History: 7/21/89, DSJ, Created. */ 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 */ /*---------------------------------------------------------------------------*/ void FreeMFOutline(void *arg) { //MFOUTLINE Outline) /* ** Parameters: ** Outline micro-feature outline to be freed ** Globals: none ** Operation: ** This routine deallocates all of the memory consumed by ** a micro-feature outline. ** Return: none ** Exceptions: none ** History: 7/27/89, DSJ, Created. */ 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 */ /*---------------------------------------------------------------------------*/ void FreeOutlines(LIST Outlines) { /* ** Parameters: ** Outlines list of mf-outlines to be freed ** Globals: none ** Operation: Release all memory consumed by the specified list ** of outlines. ** Return: none ** Exceptions: none ** History: Thu Dec 13 16:14:50 1990, DSJ, Created. */ destroy_nodes(Outlines, FreeMFOutline); } /* FreeOutlines */ /*---------------------------------------------------------------------------*/ void MarkDirectionChanges(MFOUTLINE Outline) { /* ** Parameters: ** Outline micro-feature outline to analyze ** Globals: none ** Operation: ** 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. ** Return: none ** Exceptions: none ** History: 6/29/90, DSJ, Created. */ 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")); } /*---------------------------------------------------------------------------*/ MFOUTLINE NextExtremity(MFOUTLINE EdgePoint) { /* ** Parameters: ** EdgePoint start search from this point ** Globals: none ** Operation: ** 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). ** Return: Next extremity in the outline after EdgePoint. ** Exceptions: none ** History: 7/26/89, DSJ, Created. */ EdgePoint = NextPointAfter(EdgePoint); while (!PointAt(EdgePoint)->ExtremityMark) EdgePoint = NextPointAfter(EdgePoint); return (EdgePoint); } /* NextExtremity */ /*---------------------------------------------------------------------------*/ void NormalizeOutline(MFOUTLINE Outline, FLOAT32 XOrigin) { /* ** Parameters: ** Outline outline to be normalized ** XOrigin x-origin of text ** Globals: none ** Operation: ** 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. ** Return: none ** Exceptions: none ** History: 8/2/89, DSJ, Created. */ if (Outline == NIL_LIST) return; MFOUTLINE EdgePoint = Outline; do { MFEDGEPT *Current = PointAt(EdgePoint); Current->Point.y = MF_SCALE_FACTOR * (Current->Point.y - BASELINE_OFFSET); Current->Point.x = MF_SCALE_FACTOR * (Current->Point.x - XOrigin); EdgePoint = NextPointAfter(EdgePoint); } while (EdgePoint != Outline); } /* NormalizeOutline */ /*---------------------------------------------------------------------------*/ namespace tesseract { void Classify::NormalizeOutlines(LIST Outlines, FLOAT32 *XScale, FLOAT32 *YScale) { /* ** Parameters: ** Outlines list of outlines to be normalized ** XScale x-direction scale factor used by routine ** YScale y-direction scale factor used by routine ** Globals: ** classify_norm_method method being used for normalization ** classify_char_norm_range map radius of gyration to this value ** Operation: 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. ** Return: none (Outlines are changed and XScale and YScale are updated) ** Exceptions: none ** History: Fri Dec 14 08:14:55 1990, DSJ, Created. */ MFOUTLINE Outline; OUTLINE_STATS OutlineStats; FLOAT32 BaselineScale; switch (classify_norm_method) { case character: ComputeOutlineStats(Outlines, &OutlineStats); /* limit scale factor to avoid overscaling small blobs (.,`'), thin blobs (l1ift), and merged blobs */ *XScale = *YScale = BaselineScale = MF_SCALE_FACTOR; *XScale *= OutlineStats.Ry; *YScale *= OutlineStats.Rx; if (*XScale < classify_min_norm_scale_x) *XScale = classify_min_norm_scale_x; if (*YScale < classify_min_norm_scale_y) *YScale = classify_min_norm_scale_y; if (*XScale > classify_max_norm_scale_x && *YScale <= classify_max_norm_scale_y) *XScale = classify_max_norm_scale_x; *XScale = classify_char_norm_range * BaselineScale / *XScale; *YScale = classify_char_norm_range * BaselineScale / *YScale; iterate(Outlines) { Outline = (MFOUTLINE) first_node (Outlines); CharNormalizeOutline (Outline, OutlineStats.x, OutlineStats.y, *XScale, *YScale); } 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 ----------------------------------------------------------------------------**/ /*---------------------------------------------------------------------------*/ void ChangeDirection(MFOUTLINE Start, MFOUTLINE End, DIRECTION Direction) { /* ** Parameters: ** Start, End defines segment of outline to be modified ** Direction new direction to assign to segment ** Globals: none ** Operation: 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. ** Return: none ** Exceptions: none ** History: Fri May 4 10:42:04 1990, DSJ, Created. */ MFOUTLINE Current; for (Current = Start; Current != End; Current = NextPointAfter (Current)) PointAt (Current)->Direction = Direction; PointAt (End)->PreviousDirection = Direction; } /* ChangeDirection */ /*---------------------------------------------------------------------------*/ void CharNormalizeOutline(MFOUTLINE Outline, FLOAT32 XCenter, FLOAT32 YCenter, FLOAT32 XScale, FLOAT32 YScale) { /* ** Parameters: ** Outline outline to be character normalized ** XCenter, YCenter center point for normalization ** XScale, YScale scale factors for normalization ** Globals: none ** Operation: This routine normalizes each point in Outline by ** translating it to the specified center and scaling it ** anisotropically according to the given scale factors. ** Return: none ** Exceptions: none ** History: Fri Dec 14 10:27:11 1990, DSJ, Created. */ MFOUTLINE First, Current; MFEDGEPT *CurrentPoint; if (Outline == NIL_LIST) return; First = Outline; Current = First; do { CurrentPoint = PointAt (Current); CurrentPoint->Point.x = (CurrentPoint->Point.x - XCenter) * XScale; CurrentPoint->Point.y = (CurrentPoint->Point.y - YCenter) * YScale; Current = NextPointAfter (Current); } while (Current != First); } /* CharNormalizeOutline */ /*---------------------------------------------------------------------------*/ void ComputeDirection(MFEDGEPT *Start, MFEDGEPT *Finish, FLOAT32 MinSlope, FLOAT32 MaxSlope) { /* ** Parameters: ** Start starting point to compute direction from ** Finish finishing point to compute direction to ** MinSlope slope below which lines are horizontal ** MaxSlope slope above which lines are vertical ** Globals: none ** Operation: ** 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. ** Return: none ** Exceptions: none ** History: 7/25/89, DSJ, Created. */ 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; } /* ComputeDirection */ /*---------------------------------------------------------------------------*/ void FinishOutlineStats(register OUTLINE_STATS *OutlineStats) { /* ** Parameters: ** OutlineStats statistics about a set of outlines ** Globals: none ** Operation: Use the preliminary statistics accumulated in OutlineStats ** to compute the final statistics. ** (see Dan Johnson's Tesseract lab ** notebook #2, pgs. 74-78). ** Return: none ** Exceptions: none ** History: Fri Dec 14 10:13:36 1990, DSJ, Created. */ OutlineStats->x = 0.5 * OutlineStats->My / OutlineStats->L; OutlineStats->y = 0.5 * OutlineStats->Mx / OutlineStats->L; OutlineStats->Ix = (OutlineStats->Ix / 3.0 - OutlineStats->y * OutlineStats->Mx + OutlineStats->y * OutlineStats->y * OutlineStats->L); OutlineStats->Iy = (OutlineStats->Iy / 3.0 - OutlineStats->x * OutlineStats->My + OutlineStats->x * OutlineStats->x * OutlineStats->L); /* Ix and/or Iy could possibly be negative due to roundoff error */ if (OutlineStats->Ix < 0.0) OutlineStats->Ix = MIN_INERTIA; if (OutlineStats->Iy < 0.0) OutlineStats->Iy = MIN_INERTIA; OutlineStats->Rx = sqrt (OutlineStats->Ix / OutlineStats->L); OutlineStats->Ry = sqrt (OutlineStats->Iy / OutlineStats->L); OutlineStats->Mx *= 0.5; OutlineStats->My *= 0.5; } /* FinishOutlineStats */ /*---------------------------------------------------------------------------*/ void InitOutlineStats(OUTLINE_STATS *OutlineStats) { /* ** Parameters: ** OutlineStats stats data structure to be initialized ** Globals: none ** Operation: Initialize the outline statistics data structure so ** that it is ready to start accumulating statistics. ** Return: none ** Exceptions: none ** History: Fri Dec 14 08:55:22 1990, DSJ, Created. */ OutlineStats->Mx = 0.0; OutlineStats->My = 0.0; OutlineStats->L = 0.0; OutlineStats->x = 0.0; OutlineStats->y = 0.0; OutlineStats->Ix = 0.0; OutlineStats->Iy = 0.0; OutlineStats->Rx = 0.0; OutlineStats->Ry = 0.0; } /* InitOutlineStats */ /*---------------------------------------------------------------------------*/ MFOUTLINE NextDirectionChange(MFOUTLINE EdgePoint) { /* ** Parameters: ** EdgePoint start search from this point ** Globals: none ** Operation: ** 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). ** Return: Point of next direction change in micro-feature outline. ** Exceptions: none ** History: 7/25/89, DSJ, Created. */ 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); } /* NextDirectionChange */ /*---------------------------------------------------------------------------*/ void UpdateOutlineStats(register OUTLINE_STATS *OutlineStats, register FLOAT32 x1, register FLOAT32 x2, register FLOAT32 y1, register FLOAT32 y2) { /* ** Parameters: ** OutlineStats statistics to add this segment to ** x1, y1, x2, y2 segment to be added to statistics ** Globals: none ** Operation: This routine adds the statistics for the specified ** line segment to OutlineStats. The statistics that are ** kept are: ** sum of length of all segments ** sum of 2*Mx for all segments ** sum of 2*My for all segments ** sum of 2*Mx*(y1+y2) - L*y1*y2 for all segments ** sum of 2*My*(x1+x2) - L*x1*x2 for all segments ** These numbers, once collected can later be used to easily ** compute the center of mass, first and second moments, ** and radii of gyration. (see Dan Johnson's Tesseract lab ** notebook #2, pgs. 74-78). ** Return: none ** Exceptions: none ** History: Fri Dec 14 08:59:17 1990, DSJ, Created. */ register FLOAT64 L; register FLOAT64 Mx2; register FLOAT64 My2; /* compute length of segment */ L = sqrt ((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1)); OutlineStats->L += L; /* compute 2Mx and 2My components */ Mx2 = L * (y1 + y2); My2 = L * (x1 + x2); OutlineStats->Mx += Mx2; OutlineStats->My += My2; /* compute second moment component */ OutlineStats->Ix += Mx2 * (y1 + y2) - L * y1 * y2; OutlineStats->Iy += My2 * (x1 + x2) - L * x1 * x2; } /* UpdateOutlineStats */