third-party/leptonica/src/dewarp1.c
/*====================================================================*
- Copyright (C) 2001 Leptonica. All rights reserved.
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions
- are met:
- 1. Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
- 2. Redistributions in binary form must reproduce the above
- copyright notice, this list of conditions and the following
- disclaimer in the documentation and/or other materials
- provided with the distribution.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ANY
- CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*====================================================================*/
/*
* dewarp1.c
*
* Basic operations and serialization
*
* Create/destroy dewarp
* L_DEWARP *dewarpCreate()
* L_DEWARP *dewarpCreateRef()
* void dewarpDestroy()
*
* Create/destroy dewarpa
* L_DEWARPA *dewarpaCreate()
* L_DEWARPA *dewarpaCreateFromPixacomp()
* void dewarpaDestroy()
* l_int32 dewarpaDestroyDewarp()
*
* Dewarpa insertion/extraction
* l_int32 dewarpaInsertDewarp()
* static l_int32 dewarpaExtendArraysToSize()
* L_DEWARP *dewarpaGetDewarp()
*
* Setting parameters to control rendering from the model
* l_int32 dewarpaSetCurvatures()
* l_int32 dewarpaUseBothArrays()
* l_int32 dewarpaSetMaxDistance()
*
* Dewarp serialized I/O
* L_DEWARP *dewarpRead()
* L_DEWARP *dewarpReadStream()
* l_int32 dewarpWrite()
* l_int32 dewarpWriteStream()
*
* Dewarpa serialized I/O
* L_DEWARPA *dewarpaRead()
* L_DEWARPA *dewarpaReadStream()
* l_int32 dewarpaWrite()
* l_int32 dewarpaWriteStream()
*
*
* Examples of usage
* =================
*
* See dewarpaCreateFromPixacomp() for an example of the basic
* operations, starting from a set of 1 bpp images.
*
* Basic functioning to dewarp a specific single page:
* // Make the Dewarpa for the pages
* L_Dewarpa *dewa = dewarpaCreate(1, 30, 1, 15, 50);
* dewarpaSetCurvatures(dewa, -1, 5, -1, -1, -1, -1);
* dewarpaUseBothArrays(dewa, 1); // try to use both disparity
* // arrays for this example
*
* // Do the page: start with a binarized image
* Pix *pixb = "binarize"(pixs);
* // Initialize a Dewarp for this page (say, page 214)
* L_Dewarp *dew = dewarpCreate(pixb, 214);
* // Insert in Dewarpa and obtain parameters for building the model
* dewarpaInsertDewarp(dewa, dew);
* // Do the work
* dewarpBuildPageModel(dew, NULL); // no debugging
* // Optionally set rendering parameters
* // Apply model to the input pixs
* Pix *pixd;
* dewarpaApplyDisparity(dewa, 214, pixs, 255, 0, 0, &pixd, NULL);
* pixDestroy(&pixb);
*
* Basic functioning to dewarp many pages:
* // Make the Dewarpa for the set of pages; use fullres 1 bpp
* L_Dewarpa *dewa = dewarpaCreate(10, 30, 1, 15, 50);
* // Optionally set rendering parameters
* dewarpaSetCurvatures(dewa, -1, 10, -1, -1, -1, -1);
* dewarpaUseBothArrays(dewa, 0); // just use the vertical disparity
* // array for this example
*
* // Do first page: start with a binarized image
* Pix *pixb = "binarize"(pixs);
* // Initialize a Dewarp for this page (say, page 1)
* L_Dewarp *dew = dewarpCreate(pixb, 1);
* // Insert in Dewarpa and obtain parameters for building the model
* dewarpaInsertDewarp(dewa, dew);
* // Do the work
* dewarpBuildPageModel(dew, NULL); // no debugging
* dewarpMinimze(dew); // remove most heap storage
* pixDestroy(&pixb);
*
* // Do the other pages the same way
* ...
*
* // Apply models to each page; if the page model is invalid,
* // try to use a valid neighboring model. Note that the call
* // to dewarpaInsertRefModels() is optional, because it is called
* // by dewarpaApplyDisparity() on the first page it acts on.
* dewarpaInsertRefModels(dewa, 0, 1); // use debug flag to get more
* // detailed information about the page models
* [For each page, where pixs is the fullres image to be dewarped] {
* L_Dewarp *dew = dewarpaGetDewarp(dewa, pageno);
* if (dew) { // disparity model exists
* Pix *pixd;
* dewarpaApplyDisparity(dewa, pageno, pixs, 255,
* 0, 0, &pixd, NULL);
* dewarpMinimize(dew); // clean out the pix and fpix arrays
* // Squirrel pixd away somewhere ...)
* }
* }
*
* Basic functioning to dewarp a small set of pages, potentially
* using models from nearby pages:
* // (1) Generate a set of binarized images in the vicinity of the
* // pages to be dewarped. We will attempt to compute models
* // for pages from 'firstpage' to 'lastpage'.
* // Store the binarized images in a compressed array of
* // size 'n', where 'n' is the number of images to be stored,
* // and where the offset is the first page.
* PixaComp *pixac = pixacompCreateInitialized(n, firstpage, NULL,
* IFF_TIFF_G4);
* for (i = firstpage; i <= lastpage; i++) {
* Pix *pixb = "binarize"(pixs);
* pixacompReplacePix(pixac, i, pixb, IFF_TIFF_G4);
* pixDestroy(&pixb);
* }
*
* // (2) Make the Dewarpa for the pages.
* L_Dewarpa *dewa =
* dewarpaCreateFromPixacomp(pixac, 30, 15, 20);
* dewarpaUseBothArrays(dewa, 1); // try to use both disparity arrays
* // in this example
*
* // (3) Finally, apply the models. For page 'firstpage' with image pixs:
* L_Dewarp *dew = dewarpaGetDewarp(dewa, firstpage);
* if (dew) { // disparity model exists
* Pix *pixd;
* dewarpaApplyDisparity(dewa, firstpage, pixs, 255, 0, 0, &pixd, NULL);
* dewarpMinimize(dew);
* }
*
* Because in general some pages will not have enough text to build a
* model, we fill in for those pages with a reference to the page
* model to use. Both the target page and the reference page must
* have the same parity. We can also choose to use either a partial model
* (with only vertical disparity) or the full model of a nearby page.
*
* Minimizing the data in a model by stripping out images,
* numas, and full resolution disparity arrays:
* dewarpMinimize(dew);
* This can be done at any time to save memory. Serialization does
* not use the data that is stripped.
*
* You can apply any model (in a dew), stripped or not, to another image:
* // For all pages with invalid models, assign the nearest valid
* // page model with same parity.
* dewarpaInsertRefModels(dewa, 0, 0);
* // You can then apply to 'newpix' the page model that was assigned
* // to 'pageno', giving the result in pixd:
* Pix *pixd;
* dewarpaApplyDisparity(dewa, pageno, newpix, 255, 0, 0, &pixd, NULL);
*
* You can apply the disparity arrays to a deliberately undercropped
* image. Suppose that you undercrop by (left, right, top, bot), so
* that the disparity arrays are aligned with their origin at (left, top).
* Dewarp the undercropped image with:
* Pix *pixd;
* dewarpaApplyDisparity(dewa, pageno, undercropped_pix, 255,
* left, top, &pixd, NULL);
*
*
* Description of the approach to analyzing page image distortion
* ==============================================================
*
* When a book page is scanned, there are several possible causes
* for the text lines to appear to be curved:
* (1) A barrel (fish-eye) effect because the camera is at
* a finite distance from the page. Take the normal from
* the camera to the page (the 'optic axis'). Lines on
* the page "below" this point will appear to curve upward
* (negative curvature); lines "above" this will curve downward.
* (2) Radial distortion from the camera lens. Probably not
* a big factor.
* (3) Local curvature of the page in to (or out of) the image
* plane (which is perpendicular to the optic axis).
* This has no effect if the page is flat.
*
* In the following, the optic axis is in the z direction and is
* perpendicular to the xy plane;, the book is assumed to be aligned
* so that y is approximately along the binding.
* The goal is to compute the "disparity" field, D(x,y), which
* is actually a vector composed of the horizontal and vertical
* disparity fields H(x,y) and V(x,y). Each of these is a local
* function that gives the amount each point in the image is
* required to move in order to rectify the horizontal and vertical
* lines. It would also be nice to "flatten" the page to compensate
* for effect (3), foreshortening due to bending of the page into
* the z direction, but that is more difficult.
*
* Effects (1) and (2) can be directly compensated by calibrating
* the scene, using a flat page with horizontal and vertical lines.
* Then H(x,y) and V(x,y) can be found as two (non-parametric) arrays
* of values. Suppose this has been done. Then the remaining
* distortion is due to (3).
*
* We consider the simple situation where the page bending is independent
* of y, and is described by alpha(x), where alpha is the angle between
* the normal to the page and the optic axis. cos(alpha(x)) is the local
* compression factor of the page image in the horizontal direction, at x.
* Thus, if we know alpha(x), we can compute the disparity H(x) required
* to flatten the image by simply integrating 1/cos(alpha), and we could
* compute the remaining disparities, H(x,y) and V(x,y), from the
* page content, as described below. Unfortunately, we don't know
* alpha. What do we know? If there are horizontal text lines
* on the page, we can compute the vertical disparity, V(x,y), which
* is the local translation required to make the text lines parallel
* to the rasters. If the margins are left and right aligned, we can
* also estimate the horizontal disparity, H(x,y), required to have
* uniform margins. All that can be done from the image alone,
* assuming we have text lines covering a sufficient part of the page.
*
* What about alpha(x)? The basic question relating to (3) is this:
*
* Is it possible, using the shape of the text lines alone,
* to compute both the vertical and horizontal disparity fields?
*
* The underlying problem is to separate the line curvature effects due
* to the camera view from those due to actual bending of the page.
* I believe the proper way to do this is to make some measurements
* based on the camera setup, which will depend mostly on the distance
* of the camera from the page, and to a smaller extent on the location
* of the optic axis with respect to the page.
*
* Here is the procedure. Photograph a page with a fine 2D line grid
* several times, each with a different slope near the binding.
* This can be done by placing the grid page on books that have
* different shapes z(x) near the binding. For each one you can
* measure, near the binding:
* (1) ds/dy, the vertical rate of change of slope of the horizontal lines
* (2) the local horizontal compression of the vertical lines due
* to the page angle dz/dx.
* As mentioned above, the local horizontal compression is simply
* cos(dz/dx). But the measurement you can make on an actual book
* page is (1). The difficulty is to generate (2) from (1).
*
* Back to the procedure. The function in (1), ds/dy, likely needs
* to be measured at a few y locations, because the relation
* between (1) and (2) may weakly depend on the y-location with
* respect to the y-coordinate of the optic axis of the camera.
* From these measurements you can determine, for the camera setup
* that you have, the local horizontal compression, cos(dz/dx), as a
* function of the both vertical location (y) and your measured vertical
* derivative of the text line slope there, ds/dy. Then with
* appropriate smoothing of your measured values, you can set up a
* horizontal disparity array to correct for the compression due
* to dz/dx.
*
* Now consider V(x,0) and V(x,h), the vertical disparity along
* the top and bottom of the image. With a little thought you
* can convince yourself that the local foreshortening,
* as a function of x, is proportional to the difference
* between the slope of V(x,0) and V(x,h). The horizontal
* disparity can then be computed by integrating the local foreshortening
* over x. Integration of the slope of V(x,0) and V(x,h) gives
* the vertical disparity itself. We have to normalize to h, the
* height of the page. So the very simple result is that
*
* H(x) ~ (V(x,0) - V(x,h)) / h [1]
*
* which is easily computed. There is a proportionality constant
* that depends on the ratio of h to the distance to the camera.
* Can we actually believe this for the case where the bending
* is independent of y? I believe the answer is yes,
* as long as you first remove the apparent distortion due
* to the camera being at a finite distance.
*
* If you know the intersection of the optical axis with the page
* and the distance to the camera, and if the page is perpendicular
* to the optic axis, you can compute the horizontal and vertical
* disparities due to (1) and (2) and remove them. The resulting
* distortion should be entirely due to bending (3), for which
* the relation
*
* Hx(x) dx = C * ((Vx(x,0) - Vx(x, h))/h) dx [2]
*
* holds for each point in x (Hx and Vx are partial derivatives w/rt x).
* Integrating over x, and using H(0) = 0, we get the result [1].
*
* I believe this result holds differentially for each value of y, so
* that in the case where the bending is not independent of y,
* the expression (V(x,0) - V(x,h)) / h goes over to Vy(x,y). Then
*
* H(x,y) = Integral(0,x) (Vyx(x,y) dx) [3]
*
* where Vyx() is the partial derivative of V w/rt both x and y.
*
* It would be nice if there were a simple mathematical relation between
* the horizontal and vertical disparities for the situation
* where the paper bends without stretching or kinking.
* I had hoped to get a relation between H and V, such as
* Hx(x,y) ~ Vy(x,y), which would imply that H and V are real
* and imaginary parts of a complex potential, each of which
* satisfy the laplace equation. But then the gradients of the
* two potentials would be normal, and that does not appear to be the case.
* Thus, the questions of proving the relations above (for small bending),
* or finding a simpler relation between H and V than those equations,
* remain open. So far, we have only used [1] for the horizontal
* disparity H(x).
*
* In the version of the code that follows, we first use text lines
* to find V(x,y). Then, we try to compute H(x,y) that will align
* the text vertically on the left and right margins. This is not
* always possible -- sometimes the right margin is not right justified.
* By default, we don't require the horizontal disparity to have a
* valid page model for dewarping a page, but this requirement can
* be forced using dewarpaUseFullModel().
*
* As described above, one can add a y-independent component of
* the horizontal disparity H(x) to counter the foreshortening
* effect due to the bending of the page near the binding.
* This requires widening the image on the side near the binding,
* and we do not provide this option here. However, we do provide
* a function that will generate this disparity field:
* fpixExtraHorizDisparity()
*
* Here is the basic outline for building the disparity arrays.
*
* (1) Find lines going approximately through the center of the
* text in each text line. Accept only lines that are
* close in length to the longest line.
* (2) Use these lines to generate a regular and highly subsampled
* vertical disparity field V(x,y).
* (3) Interpolate this to generate a full resolution vertical
* disparity field.
* (4) For lines that are sufficiently long, determine if the lines
* are left and right-justified, and if so, construct a highly
* subsampled horizontal disparity field H(x,y) that will bring
* them into alignment.
* (5) Interpolate this to generate a full resolution horizontal
* disparity field.
* (6) Apply the vertical dewarping, followed by the horizontal dewarping.
*
* Step (1) is clearly described by the code in pixGetTextlineCenters().
*
* Steps (2) and (3) follow directly from the data in step (1),
* and constitute the bulk of the work done in dewarpBuildPageModel().
* Virtually all the noise in the data is smoothed out by doing
* least-square quadratic fits, first horizontally to the data
* points representing the text line centers, and then vertically.
* The trick is to sample these lines on a regular grid.
* First each horizontal line is sampled at equally spaced
* intervals horizontally. We thus get a set of points,
* one in each line, that are vertically aligned, and
* the data we represent is the vertical distance of each point
* from the min or max value on the curve, depending on the
* sign of the curvature component. Each of these vertically
* aligned sets of points constitutes a sampled vertical disparity,
* and we do a LS quartic fit to each of them, followed by
* vertical sampling at regular intervals. We now have a subsampled
* grid of points, all equally spaced, giving at each point the local
* vertical disparity. Finally, the full resolution vertical disparity
* is formed by interpolation. All the least square fits do a
* great job of smoothing everything out, as can be observed by
* the contour maps that are generated for the vertical disparity field.
*/
#include <math.h>
#include "allheaders.h"
static l_int32 dewarpaExtendArraysToSize(L_DEWARPA *dewa, l_int32 size);
/* Parameter values used in dewarpaCreate() */
static const l_int32 INITIAL_PTR_ARRAYSIZE = 20; /* n'import quoi */
static const l_int32 MAX_PTR_ARRAYSIZE = 10000;
static const l_int32 DEFAULT_ARRAY_SAMPLING = 30;
static const l_int32 MIN_ARRAY_SAMPLING = 8;
static const l_int32 DEFAULT_MIN_LINES = 15;
static const l_int32 MIN_MIN_LINES = 4;
static const l_int32 DEFAULT_MAX_REF_DIST = 16;
/* Parameter values used in dewarpaSetCurvatures() */
static const l_int32 DEFAULT_MAX_LINECURV = 180;
static const l_int32 DEFAULT_MIN_DIFF_LINECURV = 0;
static const l_int32 DEFAULT_MAX_DIFF_LINECURV = 200;
static const l_int32 DEFAULT_MAX_EDGECURV = 50;
static const l_int32 DEFAULT_MAX_DIFF_EDGECURV = 40;
static const l_int32 DEFAULT_MAX_EDGESLOPE = 80;
/*----------------------------------------------------------------------*
* Create/destroy Dewarp *
*----------------------------------------------------------------------*/
/*!
* dewarpCreate()
*
* Input: pixs (1 bpp)
* pageno (page number)
* Return: dew (or null on error)
*
* Notes:
* (1) The input pixs is either full resolution or 2x reduced.
* (2) The page number is typically 0-based. If scanned from a book,
* the even pages are usually on the left. Disparity arrays
* built for even pages should only be applied to even pages.
*/
L_DEWARP *
dewarpCreate(PIX *pixs,
l_int32 pageno)
{
L_DEWARP *dew;
PROCNAME("dewarpCreate");
if (!pixs)
return (L_DEWARP *)ERROR_PTR("pixs not defined", procName, NULL);
if (pixGetDepth(pixs) != 1)
return (L_DEWARP *)ERROR_PTR("pixs not 1 bpp", procName, NULL);
if ((dew = (L_DEWARP *)CALLOC(1, sizeof(L_DEWARP))) == NULL)
return (L_DEWARP *)ERROR_PTR("dew not made", procName, NULL);
dew->pixs = pixClone(pixs);
dew->pageno = pageno;
dew->w = pixGetWidth(pixs);
dew->h = pixGetHeight(pixs);
return dew;
}
/*!
* dewarpCreateRef()
*
* Input: pageno (this page number)
* refpage (page number of dewarp disparity arrays to be used)
* Return: dew (or null on error)
*
* Notes:
* (1) This specifies which dewarp struct should be used for
* the given page. It is placed in dewarpa for pages
* for which no model can be built.
* (2) This page and the reference page have the same parity and
* the reference page is the closest page with a disparity model
* to this page.
*/
L_DEWARP *
dewarpCreateRef(l_int32 pageno,
l_int32 refpage)
{
L_DEWARP *dew;
PROCNAME("dewarpCreateRef");
if ((dew = (L_DEWARP *)CALLOC(1, sizeof(L_DEWARP))) == NULL)
return (L_DEWARP *)ERROR_PTR("dew not made", procName, NULL);
dew->pageno = pageno;
dew->hasref = 1;
dew->refpage = refpage;
return dew;
}
/*!
* dewarpDestroy()
*
* Input: &dew (<will be set to null before returning>)
* Return: void
*/
void
dewarpDestroy(L_DEWARP **pdew)
{
L_DEWARP *dew;
PROCNAME("dewarpDestroy");
if (pdew == NULL) {
L_WARNING("ptr address is null!\n", procName);
return;
}
if ((dew = *pdew) == NULL)
return;
pixDestroy(&dew->pixs);
fpixDestroy(&dew->sampvdispar);
fpixDestroy(&dew->samphdispar);
fpixDestroy(&dew->fullvdispar);
fpixDestroy(&dew->fullhdispar);
numaDestroy(&dew->namidys);
numaDestroy(&dew->nacurves);
FREE(dew);
*pdew = NULL;
return;
}
/*----------------------------------------------------------------------*
* Create/destroy Dewarpa *
*----------------------------------------------------------------------*/
/*!
* dewarpaCreate()
*
* Input: nptrs (number of dewarp page ptrs; typically the number of pages)
* sampling (use 0 for default value; the minimum allowed is 8)
* redfactor (of input images: 1 is full resolution; 2 is 2x reduced)
* minlines (minimum number of lines to accept; use 0 for default)
* maxdist (for locating reference disparity; use -1 for default)
* Return: dewa (or null on error)
*
* Notes:
* (1) The sampling, minlines and maxdist parameters will be
* applied to all images.
* (2) The sampling factor is used for generating the disparity arrays
* from the input image. For 2x reduced input, use a sampling
* factor that is half the sampling you want on the full resolution
* images.
* (3) Use @redfactor = 1 for full resolution; 2 for 2x reduction.
* All input images must be at one of these two resolutions.
* (4) @minlines is the minimum number of nearly full-length lines
* required to generate a vertical disparity array. The default
* number is 15. Use a smaller number to accept a questionable
* array, but not smaller than 4.
* (5) When a model can't be built for a page, it looks up to @maxdist
* in either direction for a valid model with the same page parity.
* Use -1 for the default value of @maxdist; use 0 to avoid using
* a ref model.
* (6) The ptr array is expanded as necessary to accommodate page images.
*/
L_DEWARPA *
dewarpaCreate(l_int32 nptrs,
l_int32 sampling,
l_int32 redfactor,
l_int32 minlines,
l_int32 maxdist)
{
L_DEWARPA *dewa;
PROCNAME("dewarpaCreate");
if (nptrs <= 0)
nptrs = INITIAL_PTR_ARRAYSIZE;
if (nptrs > MAX_PTR_ARRAYSIZE)
return (L_DEWARPA *)ERROR_PTR("too many pages", procName, NULL);
if (redfactor != 1 && redfactor != 2)
return (L_DEWARPA *)ERROR_PTR("redfactor not in {1,2}",
procName, NULL);
if (sampling == 0) {
sampling = DEFAULT_ARRAY_SAMPLING;
} else if (sampling < MIN_ARRAY_SAMPLING) {
L_WARNING("sampling too small; setting to %d\n", procName,
MIN_ARRAY_SAMPLING);
sampling = MIN_ARRAY_SAMPLING;
}
if (minlines == 0) {
minlines = DEFAULT_MIN_LINES;
} else if (minlines < MIN_MIN_LINES) {
L_WARNING("minlines too small; setting to %d\n", procName,
MIN_MIN_LINES);
minlines = DEFAULT_MIN_LINES;
}
if (maxdist < 0)
maxdist = DEFAULT_MAX_REF_DIST;
if ((dewa = (L_DEWARPA *)CALLOC(1, sizeof(L_DEWARPA))) == NULL)
return (L_DEWARPA *)ERROR_PTR("dewa not made", procName, NULL);
if ((dewa->dewarp =
(L_DEWARP **)CALLOC(nptrs, sizeof(L_DEWARPA *))) == NULL)
return (L_DEWARPA *)ERROR_PTR("dewarp ptrs not made", procName, NULL);
if ((dewa->dewarpcache =
(L_DEWARP **)CALLOC(nptrs, sizeof(L_DEWARPA *))) == NULL)
return (L_DEWARPA *)ERROR_PTR("dewarpcache ptrs not made",
procName, NULL);
dewa->nalloc = nptrs;
dewa->sampling = sampling;
dewa->redfactor = redfactor;
dewa->minlines = minlines;
dewa->maxdist = maxdist;
dewa->max_linecurv = DEFAULT_MAX_LINECURV;
dewa->min_diff_linecurv = DEFAULT_MIN_DIFF_LINECURV;
dewa->max_diff_linecurv = DEFAULT_MAX_DIFF_LINECURV;
dewa->max_edgeslope = DEFAULT_MAX_EDGESLOPE;
dewa->max_edgecurv = DEFAULT_MAX_EDGECURV;
dewa->max_diff_edgecurv = DEFAULT_MAX_DIFF_EDGECURV;
return dewa;
}
/*!
* dewarpaCreateFromPixacomp()
*
* Input: pixac (pixacomp of G4, 1 bpp images; with 1x1x1 placeholders)
* useboth (0 for vert disparity; 1 for both vert and horiz)
* sampling (use -1 or 0 for default value; otherwise minimum of 5)
* minlines (minimum number of lines to accept; e.g., 10)
* maxdist (for locating reference disparity; use -1 for default)
* Return: dewa (or null on error)
*
* Notes:
* (1) The returned dewa has disparity arrays calculated and
* is ready for serialization or for use in dewarping.
* (2) The sampling, minlines and maxdist parameters are
* applied to all images. See notes in dewarpaCreate() for details.
* (3) The pixac is full. Placeholders, if any, are w=h=d=1 images,
* and the real input images are 1 bpp at full resolution.
* They are assumed to be cropped to the actual page regions,
* and may be arbitrarily sparse in the array.
* (4) The output dewarpa is indexed by the page number.
* The offset in the pixac gives the mapping between the
* array index in the pixac and the page number.
* (5) This adds the ref page models.
* (6) This can be used to make models for any desired set of pages.
* The direct models are only made for pages with images in
* the pixacomp; the ref models are made for pages of the
* same parity within @maxdist of the nearest direct model.
*/
L_DEWARPA *
dewarpaCreateFromPixacomp(PIXAC *pixac,
l_int32 useboth,
l_int32 sampling,
l_int32 minlines,
l_int32 maxdist)
{
l_int32 i, nptrs, pageno;
L_DEWARP *dew;
L_DEWARPA *dewa;
PIX *pixt;
PROCNAME("dewarpaCreateFromPixacomp");
if (!pixac)
return (L_DEWARPA *)ERROR_PTR("pixac not defined", procName, NULL);
nptrs = pixacompGetCount(pixac);
if ((dewa = dewarpaCreate(pixacompGetOffset(pixac) + nptrs,
sampling, 1, minlines, maxdist)) == NULL)
return (L_DEWARPA *)ERROR_PTR("dewa not made", procName, NULL);
dewarpaUseBothArrays(dewa, useboth);
for (i = 0; i < nptrs; i++) {
pageno = pixacompGetOffset(pixac) + i; /* index into pixacomp */
pixt = pixacompGetPix(pixac, pageno);
if (pixt && (pixGetWidth(pixt) > 1)) {
dew = dewarpCreate(pixt, pageno);
pixDestroy(&pixt);
if (!dew) {
ERROR_INT("unable to make dew!", procName, 1);
continue;
}
/* Insert into dewa for this page */
dewarpaInsertDewarp(dewa, dew);
/* Build disparity arrays for this page */
dewarpBuildPageModel(dew, NULL);
if (!dew->vsuccess) { /* will need to use model from nearby page */
dewarpaDestroyDewarp(dewa, pageno);
L_ERROR("unable to build model for page %d\n", procName, i);
continue;
}
/* Remove all extraneous data */
dewarpMinimize(dew);
}
pixDestroy(&pixt);
}
dewarpaInsertRefModels(dewa, 0, 0);
return dewa;
}
/*!
* dewarpaDestroy()
*
* Input: &dewa (<will be set to null before returning>)
* Return: void
*/
void
dewarpaDestroy(L_DEWARPA **pdewa)
{
l_int32 i;
L_DEWARP *dew;
L_DEWARPA *dewa;
PROCNAME("dewarpaDestroy");
if (pdewa == NULL) {
L_WARNING("ptr address is null!\n", procName);
return;
}
if ((dewa = *pdewa) == NULL)
return;
for (i = 0; i < dewa->nalloc; i++) {
if ((dew = dewa->dewarp[i]) != NULL)
dewarpDestroy(&dew);
if ((dew = dewa->dewarpcache[i]) != NULL)
dewarpDestroy(&dew);
}
numaDestroy(&dewa->namodels);
numaDestroy(&dewa->napages);
FREE(dewa->dewarp);
FREE(dewa->dewarpcache);
FREE(dewa);
*pdewa = NULL;
return;
}
/*!
* dewarpaDestroyDewarp()
*
* Input: dewa
* pageno (of dew to be destroyed)
* Return: 0 if OK, 1 on error
*/
l_int32
dewarpaDestroyDewarp(L_DEWARPA *dewa,
l_int32 pageno)
{
L_DEWARP *dew;
PROCNAME("dewarpaDestroyDewarp");
if (!dewa)
return ERROR_INT("dewa or dew not defined", procName, 1);
if (pageno < 0 || pageno > dewa->maxpage)
return ERROR_INT("page out of bounds", procName, 1);
if ((dew = dewa->dewarp[pageno]) == NULL)
return ERROR_INT("dew not defined", procName, 1);
dewarpDestroy(&dew);
dewa->dewarp[pageno] = NULL;
return 0;
}
/*----------------------------------------------------------------------*
* Dewarpa insertion/extraction *
*----------------------------------------------------------------------*/
/*!
* dewarpaInsertDewarp()
*
* Input: dewarpa
* dewarp (to be added)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) This inserts the dewarp into the array, which now owns it.
* It also keeps track of the largest page number stored.
* It must be done before the disparity model is built.
* (2) Note that this differs from the usual method of filling out
* arrays in leptonica, where the arrays are compact and
* new elements are typically added to the end. Here,
* the dewarp can be added anywhere, even beyond the initial
* allocation.
*/
l_int32
dewarpaInsertDewarp(L_DEWARPA *dewa,
L_DEWARP *dew)
{
l_int32 pageno, n, newsize;
L_DEWARP *prevdew;
PROCNAME("dewarpaInsertDewarp");
if (!dewa)
return ERROR_INT("dewa not defined", procName, 1);
if (!dew)
return ERROR_INT("dew not defined", procName, 1);
dew->dewa = dewa;
pageno = dew->pageno;
if (pageno > MAX_PTR_ARRAYSIZE)
return ERROR_INT("too many pages", procName, 1);
if (pageno > dewa->maxpage)
dewa->maxpage = pageno;
dewa->modelsready = 0; /* force re-evaluation at application time */
/* Extend ptr array if necessary */
n = dewa->nalloc;
newsize = n;
if (pageno >= 2 * n)
newsize = 2 * pageno;
else if (pageno >= n)
newsize = 2 * n;
if (newsize > n)
dewarpaExtendArraysToSize(dewa, newsize);
if ((prevdew = dewarpaGetDewarp(dewa, pageno)) != NULL)
dewarpDestroy(&prevdew);
dewa->dewarp[pageno] = dew;
dew->sampling = dewa->sampling;
dew->redfactor = dewa->redfactor;
dew->minlines = dewa->minlines;
/* Get the dimensions of the sampled array. This will be
* stored in an fpix, and the input resolution version is
* guaranteed to be larger than pixs. However, if you
* want to apply the disparity to an image with a width
* w > nx * s - 2 * s + 2
* you will need to extend the input res fpix.
* And similarly for h. */
dew->nx = (dew->w + 2 * dew->sampling - 2) / dew->sampling;
dew->ny = (dew->h + 2 * dew->sampling - 2) / dew->sampling;
return 0;
}
/*!
* dewarpaExtendArraysToSize()
*
* Input: dewa
* size (new size of dewarpa array)
* Return: 0 if OK; 1 on error
*
* Notes:
* (1) If necessary, reallocs main and cache dewarpa ptr arrays to @size.
*/
static l_int32
dewarpaExtendArraysToSize(L_DEWARPA *dewa,
l_int32 size)
{
PROCNAME("dewarpaExtendArraysToSize");
if (!dewa)
return ERROR_INT("dewa not defined", procName, 1);
if (size > dewa->nalloc) {
if ((dewa->dewarp = (L_DEWARP **)reallocNew((void **)&dewa->dewarp,
sizeof(L_DEWARP *) * dewa->nalloc,
size * sizeof(L_DEWARP *))) == NULL)
return ERROR_INT("new ptr array not returned", procName, 1);
if ((dewa->dewarpcache =
(L_DEWARP **)reallocNew((void **)&dewa->dewarpcache,
sizeof(L_DEWARP *) * dewa->nalloc,
size * sizeof(L_DEWARP *))) == NULL)
return ERROR_INT("new ptr cache array not returned", procName, 1);
dewa->nalloc = size;
}
return 0;
}
/*!
* dewarpaGetDewarp()
*
* Input: dewa (populated with dewarp structs for pages)
* index (into dewa: this is the pageno)
* Return: dew (handle; still owned by dewa), or null on error
*/
L_DEWARP *
dewarpaGetDewarp(L_DEWARPA *dewa,
l_int32 index)
{
PROCNAME("dewarpaGetDewarp");
if (!dewa)
return (L_DEWARP *)ERROR_PTR("dewa not defined", procName, NULL);
if (index < 0 || index > dewa->maxpage) {
L_ERROR("index = %d is invalid; max index = %d\n",
procName, index, dewa->maxpage);
return NULL;
}
return dewa->dewarp[index];
}
/*----------------------------------------------------------------------*
* Setting parameters to control rendering from the model *
*----------------------------------------------------------------------*/
/*!
* dewarpaSetCurvatures()
*
* Input: dewa
* max_linecurv (-1 for default)
* min_diff_linecurv (-1 for default; 0 to accept all models)
* max_diff_linecurv (-1 for default)
* max_edgecurv (-1 for default)
* max_diff_edgecurv (-1 for default)
* max_edgeslope (-1 for default)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) Approximating the line by a quadratic, the coefficent
* of the quadratic term is the curvature, and distance
* units are in pixels (of course). The curvature is very
* small, so we multiply by 10^6 and express the constraints
* on the model curvatures in micro-units.
* (2) This sets five curvature thresholds and a slope threshold:
* * the maximum absolute value of the vertical disparity
* line curvatures
* * the minimum absolute value of the largest difference in
* vertical disparity line curvatures (Use a value of 0
* to accept all models.)
* * the maximum absolute value of the largest difference in
* vertical disparity line curvatures
* * the maximum absolute value of the left and right edge
* curvature for the horizontal disparity
* * the maximum absolute value of the difference between
* left and right edge curvature for the horizontal disparity
* all in micro-units, for dewarping to take place.
* Use -1 for default values.
* (3) An image with a line curvature less than about 0.00001
* has fairly straight textlines. This is 10 micro-units.
* (4) For example, if @max_linecurv == 100, this would prevent dewarping
* if any of the lines has a curvature exceeding 100 micro-units.
* A model having maximum line curvature larger than about 150
* micro-units should probably not be used.
* (5) A model having a left or right edge curvature larger than
* about 100 micro-units should probably not be used.
*/
l_int32
dewarpaSetCurvatures(L_DEWARPA *dewa,
l_int32 max_linecurv,
l_int32 min_diff_linecurv,
l_int32 max_diff_linecurv,
l_int32 max_edgecurv,
l_int32 max_diff_edgecurv,
l_int32 max_edgeslope)
{
PROCNAME("dewarpaSetCurvatures");
if (!dewa)
return ERROR_INT("dewa not defined", procName, 1);
if (max_linecurv == -1)
dewa->max_linecurv = DEFAULT_MAX_LINECURV;
else
dewa->max_linecurv = L_ABS(max_linecurv);
if (min_diff_linecurv == -1)
dewa->min_diff_linecurv = DEFAULT_MIN_DIFF_LINECURV;
else
dewa->min_diff_linecurv = L_ABS(min_diff_linecurv);
if (max_diff_linecurv == -1)
dewa->max_diff_linecurv = DEFAULT_MAX_DIFF_LINECURV;
else
dewa->max_diff_linecurv = L_ABS(max_diff_linecurv);
if (max_edgecurv == -1)
dewa->max_edgecurv = DEFAULT_MAX_EDGECURV;
else
dewa->max_edgecurv = L_ABS(max_edgecurv);
if (max_diff_edgecurv == -1)
dewa->max_diff_edgecurv = DEFAULT_MAX_DIFF_EDGECURV;
else
dewa->max_diff_edgecurv = L_ABS(max_diff_edgecurv);
if (max_edgeslope == -1)
dewa->max_edgeslope = DEFAULT_MAX_EDGESLOPE;
else
dewa->max_edgeslope = L_ABS(max_edgeslope);
dewa->modelsready = 0; /* force validation */
return 0;
}
/*!
* dewarpaUseBothArrays()
*
* Input: dewa
* useboth (0 for false, 1 for true)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) This sets the useboth field. If set, this will attempt
* to apply both vertical and horizontal disparity arrays.
* Note that a model with only a vertical disparity array will
* always be valid.
*/
l_int32
dewarpaUseBothArrays(L_DEWARPA *dewa,
l_int32 useboth)
{
PROCNAME("dewarpaUseBothArrays");
if (!dewa)
return ERROR_INT("dewa not defined", procName, 1);
dewa->useboth = useboth;
dewa->modelsready = 0; /* force validation */
return 0;
}
/*!
* dewarpaSetMaxDistance()
*
* Input: dewa
* maxdist (for using ref models)
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) This sets the maxdist field.
*/
l_int32
dewarpaSetMaxDistance(L_DEWARPA *dewa,
l_int32 maxdist)
{
PROCNAME("dewarpaSetMaxDistance");
if (!dewa)
return ERROR_INT("dewa not defined", procName, 1);
dewa->maxdist = maxdist;
dewa->modelsready = 0; /* force validation */
return 0;
}
/*----------------------------------------------------------------------*
* Dewarp serialized I/O *
*----------------------------------------------------------------------*/
/*!
* dewarpRead()
*
* Input: filename
* Return: dew, or null on error
*/
L_DEWARP *
dewarpRead(const char *filename)
{
FILE *fp;
L_DEWARP *dew;
PROCNAME("dewarpRead");
if (!filename)
return (L_DEWARP *)ERROR_PTR("filename not defined", procName, NULL);
if ((fp = fopenReadStream(filename)) == NULL)
return (L_DEWARP *)ERROR_PTR("stream not opened", procName, NULL);
if ((dew = dewarpReadStream(fp)) == NULL) {
fclose(fp);
return (L_DEWARP *)ERROR_PTR("dew not read", procName, NULL);
}
fclose(fp);
return dew;
}
/*!
* dewarpReadStream()
*
* Input: stream
* Return: dew, or null on error
*
* Notes:
* (1) The dewarp struct is stored in minimized format, with only
* subsampled disparity arrays.
* (2) The sampling and extra horizontal disparity parameters are
* stored here. During generation of the dewarp struct, they
* are passed in from the dewarpa. In readback, it is assumed
* that they are (a) the same for each page and (b) the same
* as the values used to create the dewarpa.
*/
L_DEWARP *
dewarpReadStream(FILE *fp)
{
l_int32 version, sampling, redfactor, minlines, pageno, hasref, refpage;
l_int32 w, h, nx, ny, vdispar, hdispar, nlines;
l_int32 mincurv, maxcurv, leftslope, rightslope, leftcurv, rightcurv;
L_DEWARP *dew;
FPIX *fpixv, *fpixh;
PROCNAME("dewarpReadStream");
if (!fp)
return (L_DEWARP *)ERROR_PTR("stream not defined", procName, NULL);
if (fscanf(fp, "\nDewarp Version %d\n", &version) != 1)
return (L_DEWARP *)ERROR_PTR("not a dewarp file", procName, NULL);
if (version != DEWARP_VERSION_NUMBER)
return (L_DEWARP *)ERROR_PTR("invalid dewarp version", procName, NULL);
if (fscanf(fp, "pageno = %d\n", &pageno) != 1)
return (L_DEWARP *)ERROR_PTR("read fail for pageno", procName, NULL);
if (fscanf(fp, "hasref = %d, refpage = %d\n", &hasref, &refpage) != 2)
return (L_DEWARP *)ERROR_PTR("read fail for hasref, refpage",
procName, NULL);
if (fscanf(fp, "sampling = %d, redfactor = %d\n", &sampling, &redfactor)
!= 2)
return (L_DEWARP *)ERROR_PTR("read fail for sampling/redfactor",
procName, NULL);
if (fscanf(fp, "nlines = %d, minlines = %d\n", &nlines, &minlines) != 2)
return (L_DEWARP *)ERROR_PTR("read fail for nlines/minlines",
procName, NULL);
if (fscanf(fp, "w = %d, h = %d\n", &w, &h) != 2)
return (L_DEWARP *)ERROR_PTR("read fail for w, h", procName, NULL);
if (fscanf(fp, "nx = %d, ny = %d\n", &nx, &ny) != 2)
return (L_DEWARP *)ERROR_PTR("read fail for nx, ny", procName, NULL);
if (fscanf(fp, "vert_dispar = %d, horiz_dispar = %d\n", &vdispar, &hdispar)
!= 2)
return (L_DEWARP *)ERROR_PTR("read fail for flags", procName, NULL);
if (vdispar) {
if (fscanf(fp, "min line curvature = %d, max line curvature = %d\n",
&mincurv, &maxcurv) != 2)
return (L_DEWARP *)ERROR_PTR("read fail for mincurv & maxcurv",
procName, NULL);
}
if (hdispar) {
if (fscanf(fp, "left edge slope = %d, right edge slope = %d\n",
&leftslope, &rightslope) != 2)
return (L_DEWARP *)ERROR_PTR("read fail for leftslope & rightslope",
procName, NULL);
if (fscanf(fp, "left edge curvature = %d, right edge curvature = %d\n",
&leftcurv, &rightcurv) != 2)
return (L_DEWARP *)ERROR_PTR("read fail for leftcurv & rightcurv",
procName, NULL);
}
if (vdispar) {
if ((fpixv = fpixReadStream(fp)) == NULL)
return (L_DEWARP *)ERROR_PTR("read fail for vdispar",
procName, NULL);
}
if (hdispar) {
if ((fpixh = fpixReadStream(fp)) == NULL)
return (L_DEWARP *)ERROR_PTR("read fail for hdispar",
procName, NULL);
}
getc(fp);
dew = (L_DEWARP *)CALLOC(1, sizeof(L_DEWARP));
dew->w = w;
dew->h = h;
dew->pageno = pageno;
dew->sampling = sampling;
dew->redfactor = redfactor;
dew->minlines = minlines;
dew->nlines = nlines;
dew->hasref = hasref;
dew->refpage = refpage;
if (hasref == 0) /* any dew without a ref has an actual model */
dew->vsuccess = 1;
dew->nx = nx;
dew->ny = ny;
if (vdispar) {
dew->mincurv = mincurv;
dew->maxcurv = maxcurv;
dew->vsuccess = 1;
dew->sampvdispar = fpixv;
}
if (hdispar) {
dew->leftslope = leftslope;
dew->rightslope = rightslope;
dew->leftcurv = leftcurv;
dew->rightcurv = rightcurv;
dew->hsuccess = 1;
dew->samphdispar = fpixh;
}
return dew;
}
/*!
* dewarpWrite()
*
* Input: filename
* dew
* Return: 0 if OK, 1 on error
*/
l_int32
dewarpWrite(const char *filename,
L_DEWARP *dew)
{
FILE *fp;
PROCNAME("dewarpWrite");
if (!filename)
return ERROR_INT("filename not defined", procName, 1);
if (!dew)
return ERROR_INT("dew not defined", procName, 1);
if ((fp = fopenWriteStream(filename, "wb")) == NULL)
return ERROR_INT("stream not opened", procName, 1);
if (dewarpWriteStream(fp, dew))
return ERROR_INT("dew not written to stream", procName, 1);
fclose(fp);
return 0;
}
/*!
* dewarpWriteStream()
*
* Input: stream (opened for "wb")
* dew
* Return: 0 if OK, 1 on error
*
* Notes:
* (1) This should not be written if there is no sampled
* vertical disparity array, which means that no model has
* been built for this page.
*/
l_int32
dewarpWriteStream(FILE *fp,
L_DEWARP *dew)
{
l_int32 vdispar, hdispar;
PROCNAME("dewarpWriteStream");
if (!fp)
return ERROR_INT("stream not defined", procName, 1);
if (!dew)
return ERROR_INT("dew not defined", procName, 1);
fprintf(fp, "\nDewarp Version %d\n", DEWARP_VERSION_NUMBER);
fprintf(fp, "pageno = %d\n", dew->pageno);
fprintf(fp, "hasref = %d, refpage = %d\n", dew->hasref, dew->refpage);
fprintf(fp, "sampling = %d, redfactor = %d\n",
dew->sampling, dew->redfactor);
fprintf(fp, "nlines = %d, minlines = %d\n", dew->nlines, dew->minlines);
fprintf(fp, "w = %d, h = %d\n", dew->w, dew->h);
fprintf(fp, "nx = %d, ny = %d\n", dew->nx, dew->ny);
vdispar = (dew->sampvdispar) ? 1 : 0;
hdispar = (dew->samphdispar) ? 1 : 0;
fprintf(fp, "vert_dispar = %d, horiz_dispar = %d\n", vdispar, hdispar);
if (vdispar)
fprintf(fp, "min line curvature = %d, max line curvature = %d\n",
dew->mincurv, dew->maxcurv);
if (hdispar) {
fprintf(fp, "left edge slope = %d, right edge slope = %d\n",
dew->leftslope, dew->rightslope);
fprintf(fp, "left edge curvature = %d, right edge curvature = %d\n",
dew->leftcurv, dew->rightcurv);
}
if (vdispar) fpixWriteStream(fp, dew->sampvdispar);
if (hdispar) fpixWriteStream(fp, dew->samphdispar);
fprintf(fp, "\n");
if (!vdispar)
L_WARNING("no disparity arrays!\n", procName);
return 0;
}
/*----------------------------------------------------------------------*
* Dewarpa serialized I/O *
*----------------------------------------------------------------------*/
/*!
* dewarpaRead()
*
* Input: filename
* Return: dewa, or null on error
*/
L_DEWARPA *
dewarpaRead(const char *filename)
{
FILE *fp;
L_DEWARPA *dewa;
PROCNAME("dewarpaRead");
if (!filename)
return (L_DEWARPA *)ERROR_PTR("filename not defined", procName, NULL);
if ((fp = fopenReadStream(filename)) == NULL)
return (L_DEWARPA *)ERROR_PTR("stream not opened", procName, NULL);
if ((dewa = dewarpaReadStream(fp)) == NULL) {
fclose(fp);
return (L_DEWARPA *)ERROR_PTR("dewa not read", procName, NULL);
}
fclose(fp);
return dewa;
}
/*!
* dewarpaReadStream()
*
* Input: stream
* Return: dewa, or null on error
*
* Notes:
* (1) The serialized dewarp contains a Numa that gives the
* (increasing) page number of the dewarp structs that are
* contained.
* (2) Reference pages are added in after readback.
*/
L_DEWARPA *
dewarpaReadStream(FILE *fp)
{
l_int32 i, version, ndewarp, maxpage;
l_int32 sampling, redfactor, minlines, maxdist, useboth;
l_int32 max_linecurv, min_diff_linecurv, max_diff_linecurv;
l_int32 max_edgeslope, max_edgecurv, max_diff_edgecurv;
L_DEWARP *dew;
L_DEWARPA *dewa;
NUMA *namodels;
PROCNAME("dewarpaReadStream");
if (!fp)
return (L_DEWARPA *)ERROR_PTR("stream not defined", procName, NULL);
if (fscanf(fp, "\nDewarpa Version %d\n", &version) != 1)
return (L_DEWARPA *)ERROR_PTR("not a dewarpa file", procName, NULL);
if (version != DEWARP_VERSION_NUMBER)
return (L_DEWARPA *)ERROR_PTR("invalid dewarp version", procName, NULL);
if (fscanf(fp, "ndewarp = %d, maxpage = %d\n", &ndewarp, &maxpage) != 2)
return (L_DEWARPA *)ERROR_PTR("read fail for maxpage+", procName, NULL);
if (fscanf(fp,
"sampling = %d, redfactor = %d, minlines = %d, maxdist = %d\n",
&sampling, &redfactor, &minlines, &maxdist) != 4)
return (L_DEWARPA *)ERROR_PTR("read fail for 4 params", procName, NULL);
if (fscanf(fp,
"max_linecurv = %d, min_diff_linecurv = %d, max_diff_linecurv = %d\n",
&max_linecurv, &min_diff_linecurv, &max_diff_linecurv) != 3)
return (L_DEWARPA *)ERROR_PTR("read fail for linecurv", procName, NULL);
if (fscanf(fp,
"max_edgeslope = %d, max_edgecurv = %d, max_diff_edgecurv = %d\n",
&max_edgeslope, &max_edgecurv, &max_diff_edgecurv) != 3)
return (L_DEWARPA *)ERROR_PTR("read fail for edgecurv", procName, NULL);
if (fscanf(fp, "fullmodel = %d\n", &useboth) != 1)
return (L_DEWARPA *)ERROR_PTR("read fail for useboth", procName, NULL);
dewa = dewarpaCreate(maxpage + 1, sampling, redfactor, minlines, maxdist);
dewa->maxpage = maxpage;
dewa->max_linecurv = max_linecurv;
dewa->min_diff_linecurv = min_diff_linecurv;
dewa->max_diff_linecurv = max_diff_linecurv;
dewa->max_edgeslope = max_edgeslope;
dewa->max_edgecurv = max_edgecurv;
dewa->max_diff_edgecurv = max_diff_edgecurv;
dewa->useboth = useboth;
namodels = numaCreate(ndewarp);
dewa->namodels = namodels;
for (i = 0; i < ndewarp; i++) {
if ((dew = dewarpReadStream(fp)) == NULL) {
L_ERROR("read fail for dew[%d]\n", procName, i);
return NULL;
}
dewarpaInsertDewarp(dewa, dew);
numaAddNumber(namodels, dew->pageno);
}
/* Validate the models and insert reference models */
dewarpaInsertRefModels(dewa, 0, 0);
return dewa;
}
/*!
* dewarpaWrite()
*
* Input: filename
* dewa
* Return: 0 if OK, 1 on error
*/
l_int32
dewarpaWrite(const char *filename,
L_DEWARPA *dewa)
{
FILE *fp;
PROCNAME("dewarpaWrite");
if (!filename)
return ERROR_INT("filename not defined", procName, 1);
if (!dewa)
return ERROR_INT("dewa not defined", procName, 1);
if ((fp = fopenWriteStream(filename, "wb")) == NULL)
return ERROR_INT("stream not opened", procName, 1);
if (dewarpaWriteStream(fp, dewa))
return ERROR_INT("dewa not written to stream", procName, 1);
fclose(fp);
return 0;
}
/*!
* dewarpaWriteStream()
*
* Input: stream (opened for "wb")
* dewa
* Return: 0 if OK, 1 on error
*/
l_int32
dewarpaWriteStream(FILE *fp,
L_DEWARPA *dewa)
{
l_int32 ndewarp, i, pageno;
PROCNAME("dewarpaWriteStream");
if (!fp)
return ERROR_INT("stream not defined", procName, 1);
if (!dewa)
return ERROR_INT("dewa not defined", procName, 1);
/* Generate the list of page numbers for which a model exists.
* Note that no attempt is made to determine if the model is
* valid, because that determination is associated with
* using the model to remove the warping, which typically
* can happen later, after all the models have been built. */
dewarpaListPages(dewa);
if (!dewa->namodels)
return ERROR_INT("dewa->namodels not made", procName, 1);
ndewarp = numaGetCount(dewa->namodels); /* with actual page models */
fprintf(fp, "\nDewarpa Version %d\n", DEWARP_VERSION_NUMBER);
fprintf(fp, "ndewarp = %d, maxpage = %d\n", ndewarp, dewa->maxpage);
fprintf(fp, "sampling = %d, redfactor = %d, minlines = %d, maxdist = %d\n",
dewa->sampling, dewa->redfactor, dewa->minlines, dewa->maxdist);
fprintf(fp,
"max_linecurv = %d, min_diff_linecurv = %d, max_diff_linecurv = %d\n",
dewa->max_linecurv, dewa->min_diff_linecurv, dewa->max_diff_linecurv);
fprintf(fp,
"max_edgeslope = %d, max_edgecurv = %d, max_diff_edgecurv = %d\n",
dewa->max_edgeslope, dewa->max_edgecurv, dewa->max_diff_edgecurv);
fprintf(fp, "fullmodel = %d\n", dewa->useboth);
for (i = 0; i < ndewarp; i++) {
numaGetIValue(dewa->namodels, i, &pageno);
dewarpWriteStream(fp, dewarpaGetDewarp(dewa, pageno));
}
return 0;
}