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- /*====================================================================*
- - 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
- - PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- - OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- - NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- - SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *====================================================================*/
- #ifndef LEPTONICA_DEWARP_H
- #define LEPTONICA_DEWARP_H
- /*
- * dewarp.h
- *
- * Data structure to hold arrays and results for generating
- * horizontal and vertical disparity arrays based on textlines.
- * Each disparity array is two-dimensional. The vertical disparity
- * array gives a vertical displacement, relative to the lowest point
- * in the textlines. The horizontal disparty array gives a horizontal
- * displacement, relative to the minimum values (for even pages)
- * or maximum values (for odd pages) of the left and right ends of
- * full textlines. Horizontal alignment always involves translations
- * away from the book gutter.
- *
- * We have intentionally separated the process of building models
- * from the rendering process that uses the models. For any page,
- * the building operation either creates an actual model (that is,
- * a model with at least the vertical disparity being computed, and
- * for which the 'success' flag is set) or fails to create a model.
- * However, at rendering time, a page can have one of two different
- * types of models.
- * (1) A valid model is an actual model that meets the rendering
- * constraints, which are limits on model curvature parameters.
- * See dewarpaTestForValidModel() for details.
- * Valid models are identified by dewarpaInsertRefModels(),
- * which sets the 'vvalid' and 'hvalid' fields. Only valid
- * models are used for rendering.
- * (2) A reference model is used by a page that doesn't have
- * a valid model, but has a nearby valid model of the same
- * parity (even/odd page) that it can use. The range in pages
- * to search for a valid model is given by the 'maxdist' field.
- *
- * If a valid vertical disparity model (VDM) is not available,
- * just use the input image. Otherwise, assuming the VDM is available:
- * (a) with useboth == 0, we use only the VDM.
- * (b) with useboth == 1, we require using the VDM and, if a valid
- * horizontal disparity model (HDM) is available, we also use it.
- *
- * The 'maxdist' parameter is input when the dewarpa is created.
- * The other rendering parameters have default values given in dewarp.c.
- * All parameters used by rendering can be set (or reset) using accessors.
- *
- * After dewarping, use of the VDM will cause all points on each
- * altered curve to have a y-value equal to the minimum. Use of
- * the HDA will cause the left and right edges of the textlines
- * to be vertically aligned if they had been typeset flush-left
- * and flush-right, respectively.
- *
- * The sampled disparity arrays are expanded to full resolution,
- * using linear interpolation, and this is further expanded
- * by slope continuation to the right and below if the image
- * is larger than the full resolution disparity arrays. Then
- * the disparity correction can be applied to the input image.
- * If the input pix are 2x reduced, the expansion from sampled
- * to full res uses the product of (sampling) * (redfactor).
- *
- * The most accurate results are produced at full resolution, and
- * this is generally recommended.
- */
- /* Note on versioning of the serialization of this data structure:
- * The dewarping utility and the stored data can be expected to change.
- * In most situations, the serialized version is ephemeral -- it is
- * not needed after being used. No functions will be provided to
- * convert between different versions. */
- #define DEWARP_VERSION_NUMBER 4
- struct L_Dewarpa
- {
- l_int32 nalloc; /* size of dewarp ptr array */
- l_int32 maxpage; /* maximum page number in array */
- struct L_Dewarp **dewarp; /* array of ptrs to page dewarp */
- struct L_Dewarp **dewarpcache; /* array of ptrs to cached dewarps */
- struct Numa *namodels; /* list of page numbers for pages */
- /* with page models */
- struct Numa *napages; /* list of page numbers with either */
- /* page models or ref page models */
- l_int32 redfactor; /* reduction factor of input: 1 or 2 */
- l_int32 sampling; /* disparity arrays sampling factor */
- l_int32 minlines; /* min number of long lines required */
- l_int32 maxdist; /* max distance for getting ref pages */
- l_int32 max_linecurv; /* maximum abs line curvature, */
- /* in micro-units */
- l_int32 min_diff_linecurv; /* minimum abs diff line curvature */
- /* in micro-units */
- l_int32 max_diff_linecurv; /* maximum abs diff line curvature */
- /* in micro-units */
- l_int32 max_edgeslope; /* maximum abs left or right edge */
- /* slope, in milli-units */
- l_int32 max_edgecurv; /* maximum abs left or right edge */
- /* curvature, in micro-units */
- l_int32 max_diff_edgecurv; /* maximum abs diff left-right */
- /* edge curvature, in micro-units */
- l_int32 useboth; /* use both disparity arrays if */
- /* available; just vertical otherwise */
- l_int32 modelsready; /* invalid models have been removed */
- /* and refs built against valid set */
- };
- typedef struct L_Dewarpa L_DEWARPA;
- struct L_Dewarp
- {
- struct L_Dewarpa *dewa; /* ptr to parent (not owned) */
- struct Pix *pixs; /* source pix, 1 bpp */
- struct FPix *sampvdispar; /* sampled vert disparity array */
- struct FPix *samphdispar; /* sampled horiz disparity array */
- struct FPix *fullvdispar; /* full vert disparity array */
- struct FPix *fullhdispar; /* full horiz disparity array */
- struct Numa *namidys; /* sorted y val of midpoint each line */
- struct Numa *nacurves; /* sorted curvature of each line */
- l_int32 w; /* width of source image */
- l_int32 h; /* height of source image */
- l_int32 pageno; /* page number; important for reuse */
- l_int32 sampling; /* sampling factor of disparity arrays */
- l_int32 redfactor; /* reduction factor of pixs: 1 or 2 */
- l_int32 minlines; /* min number of long lines required */
- l_int32 nlines; /* number of long lines found */
- l_int32 mincurv; /* min line curvature in micro-units */
- l_int32 maxcurv; /* max line curvature in micro-units */
- l_int32 leftslope; /* left edge slope in milli-units */
- l_int32 rightslope; /* right edge slope in milli-units */
- l_int32 leftcurv; /* left edge curvature in micro-units */
- l_int32 rightcurv; /* right edge curvature in micro-units */
- l_int32 nx; /* number of sampling pts in x-dir */
- l_int32 ny; /* number of sampling pts in y-dir */
- l_int32 hasref; /* 0 if normal; 1 if has a refpage */
- l_int32 refpage; /* page with disparity model to use */
- l_int32 vsuccess; /* sets to 1 if vert disparity builds */
- l_int32 hsuccess; /* sets to 1 if horiz disparity builds */
- l_int32 vvalid; /* sets to 1 if valid vert disparity */
- l_int32 hvalid; /* sets to 1 if valid horiz disparity */
- l_int32 debug; /* sets to 1 if debug output requested */
- };
- typedef struct L_Dewarp L_DEWARP;
- #endif /* LEPTONICA_DEWARP_H */
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