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https://github.com/tesseract-ocr/tesseract.git
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66 lines
2.9 KiB
C
66 lines
2.9 KiB
C
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///////////////////////////////////////////////////////////////////////
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// File: imagefind.h
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// Description: Class to find image and drawing regions in an image
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// and create a corresponding list of empty blobs.
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// Author: Ray Smith
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// Created: Fri Aug 01 10:50:01 PDT 2008
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//
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// (C) Copyright 2008, Google Inc.
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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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#ifndef TESSERACT_TEXTORD_IMAGEFIND_H__
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#define TESSERACT_TEXTORD_IMAGEFIND_H__
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struct Boxa;
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struct Pix;
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struct Pixa;
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namespace tesseract {
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// The ImageFinder class is a simple static function wrapper class that
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// exposes the FindImages function and some useful helper functions.
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class ImageFinder {
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public:
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// Finds image regions within the source pix (page image) and returns
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// the image regions as a Boxa, Pixa pair, analgous to pixConnComp.
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// The returned boxa, pixa may be NULL, meaning no images found.
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// If not NULL, they must be destroyed by the caller.
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static void FindImages(Pix* pix, Boxa** boxa, Pixa** pixa);
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// Returns true if there is a rectangle in the source pix, such that all
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// pixel rows and column slices outside of it have less than
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// min_fraction of the pixels black, and within max_skew_gradient fraction
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// of the pixels on the inside, there are at least max_fraction of the
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// pixels black. In other words, the inside of the rectangle looks roughly
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// rectangular, and the outside of it looks like extra bits.
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// On return, the rectangle is defined by x_start, y_start, x_end and y_end.
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// Note: the algorithm is iterative, allowing it to slice off pixels from
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// one edge, allowing it to then slice off more pixels from another edge.
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static bool pixNearlyRectangular(Pix* pix,
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double min_fraction, double max_fraction,
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double max_skew_gradient,
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int* x_start, int* y_start,
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int* x_end, int* y_end);
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// Given an input pix, and a bounding rectangle, the sides of the rectangle
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// are shrunk inwards until they bound any black pixels found within the
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// original rectangle.
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static void BoundsWithinRect(Pix* pix, int* x_start, int* y_start,
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int* x_end, int* y_end);
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};
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} // namespace tesseract.
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#endif // TESSERACT_TEXTORD_LINEFIND_H__
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