JPH08194816A - Segment approximation method and its system - Google Patents
Segment approximation method and its systemInfo
- Publication number
- JPH08194816A JPH08194816A JP505595A JP505595A JPH08194816A JP H08194816 A JPH08194816 A JP H08194816A JP 505595 A JP505595 A JP 505595A JP 505595 A JP505595 A JP 505595A JP H08194816 A JPH08194816 A JP H08194816A
- Authority
- JP
- Japan
- Prior art keywords
- line segment
- adjacent
- angle
- segment
- dot image
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、文字や図形等のドット
イメージデータの輪郭情報を可変長線分近似する方法お
よび方式に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for approximating contour information of dot image data such as characters and figures by variable length line segment.
【０００２】[0002]
【従来の技術】近年パーソナルコンピュータのデバイス
が発達し、高解像度の表示装置および印刷装置の普及に
より、文字や図形は高品位のアウトラインフォントによ
って出力されるようになっている。2. Description of the Related Art With the recent development of personal computer devices and the widespread use of high-resolution display devices and printing devices, characters and figures have been output in high-quality outline fonts.
【０００３】ドットイメージデータの曲線部分を近似し
てアウトラインフォントを生成する方法として、曲線近
似方法と直線近似方法が知られている。As a method for approximating a curved portion of dot image data to generate an outline font, a curve approximating method and a linear approximating method are known.
【０００４】曲線近似方法は、ドットイメージデータの
輪郭形状のうち、直線部分は線分で、また曲線部分につ
いては、これを近似する円弧あるいは数学上よく知られ
た多項式曲線、スプライン曲線、ベジェ曲線などで近似
する方法であり、輪郭形状の曲線部分を滑らかに近似す
ることができるため、曲線部分の品質が要求される用
途、特に文字イメージの表現などに広く応用されている
方法であるが、曲線部分を再びドットイメージに復元す
る際には、一般に線分の部分に比べて、超越関数演算を
含む多量の計算を実行しなければならず、ドットイメー
ジの再現に多大の処理負担がかかるため、長い処理時間
を有する。また、これを専用ハードウェアで実現しよう
とした場合、回路構造的にも専用アーキテクチャ化が困
難であり、高速処理に対する回路設計上の工夫の余地が
少なく、ただ計算速度の高速化に期待するしかないとう
いう欠点がある。In the curve approximation method, a straight line portion is a line segment in the contour shape of dot image data, and a curved line portion is a circular arc or a mathematically well-known polynomial curve, spline curve, or Bezier curve. It is a method that is widely applied to applications where the quality of the curved portion is required, especially for expressing character images, etc. When restoring a curved line portion to a dot image again, it is generally necessary to execute a large amount of calculations including transcendental function operations, as compared to a line segment portion, and it takes a great deal of processing load to reproduce a dot image. , With long processing time. Also, if this is to be realized with dedicated hardware, it is difficult to create a dedicated architecture in terms of circuit structure, and there is little room for devising the circuit design for high-speed processing, and there is no expectation for higher calculation speed. There is a drawback that it does not exist.
【０００５】一方、直線近似方法として、従来から図６
に示すような方法が知られている。すなわち、図６に示
すように輪郭点列上の特定の区間の始点と終点を結ぶ線
分（粗近似固定長線分）と、その区間における輪郭点列
の各座標点との距離を計算し、その最大誤差を与える点
を終点とすることを繰り返し、最大誤差がある一定の許
容値を超えなくなったときの終点を求め、得られた終点
と始点を結ぶ線分を輪郭当該区間の近似直線とし、これ
を輪郭全体にわたって繰り返すことにより線分近似を行
う方法である。On the other hand, as a straight-line approximation method, the conventional method shown in FIG.
A method as shown in is known. That is, as shown in FIG. 6, a distance between a line segment (coarse approximate fixed length line segment) connecting a start point and an end point of a specific section on the contour point sequence and each coordinate point of the contour point sequence in the section is calculated, The point that gives the maximum error is repeatedly set as the end point, the end point when the maximum error does not exceed a certain allowable value is obtained, and the line segment connecting the obtained end point and the start point is defined as the approximate straight line of the relevant section. , Is a method of performing line segment approximation by repeating this over the entire contour.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、従来の
直線近似方法は、輪郭を構成するすべての点、またはア
ルゴリズムの工夫により一部の点を選択して、粗近似固
定長線分との距離を計算しなければならず、多量の計算
処理を必要とする。特に計算内容は、輪郭点と粗近似固
定長線分との距離を求めねばならず、コンピュータ処理
上負荷の大きな２乗あるいは平方根処理を必要としてい
た。However, according to the conventional straight line approximation method, all the points constituting the contour or some points are selected by devising the algorithm and the distance to the rough approximation fixed length line segment is calculated. This requires a large amount of calculation processing. In particular, the content of the calculation has to find the distance between the contour point and the fixed-length fixed-length line segment, and thus requires square or square root processing which has a heavy load on computer processing.
【０００７】一書体当り７，０００〜１２，０００の文
字にもおよぶ日本語の文字において、ドットイメージの
文字データから直線アウトライン文字データを生成する
ための従来の直線近似方法でも、膨大な処理時間を要す
るという問題点があった。Even in the conventional straight-line approximation method for generating straight-line outline character data from character data of a dot image for Japanese characters having 7,000 to 12,000 characters per typeface, a huge processing time is required. There was a problem that it required.
【０００８】本発明の課題は、処理時間を大幅に短縮で
きるドットイメージの文字データから直線アウトライン
文字データを生成するための線分近似方法およびその方
式を提供することにある。An object of the present invention is to provide a line segment approximation method and method for generating straight line outline character data from character data of a dot image, which can significantly reduce the processing time.
【０００９】[0009]
【課題を解決するための手段】本発明者は、上記課題を
解決すべく鋭意研究を重ねた結果、まず十分過ぎる精度
を持った固定長の線分でドットイメージの輪郭を分割
し、隣接する固定長線分同士の角度を評価し、その評価
により線分のベクトル和を取ることにより可変長の線分
近似を得る方法により上記課題が解決できることを見い
だし、本発明を完成するに至った。As a result of intensive studies to solve the above-mentioned problems, the present inventor first divided the contours of dot images into fixed-length line segments with sufficient accuracy and adjoining them. The inventors have found that the above problems can be solved by a method of evaluating the angles between fixed-length line segments and obtaining the vector sum of the line segments by the evaluation to solve the above problems, and completed the present invention.
【００１０】すなわち、本発明は、ドットイメージの輪
郭を線分近似する方法において、原ドットイメージの輪
郭を固定長線分で高精度に分割し、基準線分と隣接線分
の角度を算出し、算出した角度を評価し、基準線分と隣
接線分を直線近似できると評価した場合は、基準線分と
隣接線分のベクトル和を求めベクトル線分を発生させ
て、ベクトル線分を基準線分とし、基準線分と隣接線分
を直線近似できないと評価した場合は、隣接線分を基準
線分とし、ドットイメージの分割点の最終点に至るまで
繰り返すことを特徴とするドットイメージデータの輪郭
の線分近似方法、およびドットイメージの輪郭を線分近
似する方式において、原ドットイメージの輪郭を固定長
線分で高精度に分割する輪郭分割部と、基準線分と隣接
線分の角度を算出する角度算出部と、角度算出部により
算出された角度を評価する角度評価部と、基準線分と隣
接線分のベクトル和を求めベクトル線分を発生させるベ
クトル合成部とを備え、基準線分と隣接線分を直線近似
できると評価した場合は、基準線分と隣接線分のベクト
ル和を求めベクトル線分を発生させてベクトル線分を基
準線分とし、基準線分と隣接線分を直線近似できないと
評価した場合は、隣接線分を基準線分とし、ドットイメ
ージの分割点の最終点に至るまで繰り返すように構成し
たことを特徴とするドットイメージデータの輪郭の線分
近似方式に関するものである。That is, according to the present invention, in the method of approximating the contour of the dot image by the line segment, the contour of the original dot image is divided with a fixed long line segment with high accuracy, and the angle between the reference segment and the adjacent segment is calculated. If the calculated angle is evaluated and it is evaluated that the reference line segment and the adjacent line segment can be linearly approximated, the vector sum of the reference line segment and the adjacent line segment is calculated to generate the vector line segment, and the vector line segment is set to the reference line. If it is evaluated that the reference line segment and the adjacent line segment cannot be linearly approximated, the adjacent line segment is set as the reference line segment, and it is repeated until the final point of the dot image division points. In the contour line segment approximation method and the method for approximating the contour of a dot image, the contour segmentation part that accurately divides the contour of the original dot image with a fixed long line segment and the angle between the reference line segment and the adjacent segment Calculate An angle calculation unit, an angle evaluation unit that evaluates the angle calculated by the angle calculation unit, and a vector synthesis unit that generates a vector line segment by obtaining the vector sum of the reference line segment and the adjacent line segment, and the reference line segment If it is evaluated that the adjacent line segment can be approximated by a straight line, the vector sum of the reference line segment and the adjacent line segment is calculated to generate the vector line segment, and the vector line segment is set as the reference line segment. When it is evaluated that approximation is not possible, the line segment approximation method for the contour of dot image data is characterized in that the adjacent line segments are used as reference line segments and are repeated until the final point of the dot image division points. Is.
【００１１】なお、本発明における基準線分とは、角度
を算出するための基準となる線分であり、隣接線分と
は、基準線分に隣接する線分で、近似処理の施されてい
ない固定長線分をいうものとする。The reference line segment in the present invention is a reference line segment for calculating an angle, and the adjacent line segment is a line segment adjacent to the reference line segment, which has been subjected to approximation processing. A fixed-length line segment that does not exist.
【００１２】本発明の線分近似方法の原理について、図
１〜図３を用いて説明する。The principle of the line segment approximation method of the present invention will be described with reference to FIGS.
【００１３】図１に示すように、ドットイメージの輪郭
を内接または外接する形で、固定長線分で高精度に分割
する。本発明の分割における高精度とは、固定長線分の
近似誤差が、従来の線分近似方法の場合に比べて十分高
い精度に設定するすることをいう。As shown in FIG. 1, a contour of a dot image is inscribed or circumscribed and is divided with a fixed length line segment with high precision. The high precision in the division of the present invention means that the approximation error of a fixed-length line segment is set to a sufficiently high precision as compared with the conventional line segment approximation method.
【００１４】例えば、従来の線分近似方式では、固定長
の線分でおおまかに近似しておき、後に誤差距離の評価
を行って、予め設定されていた許容誤差より誤差距離が
大きな箇所においては、順次分割していくために、当初
の分割前の固定長線分が最大の長さを持つ近似線分とな
るために、これをあまり短く設定してしまうと、緩やか
な曲線部分における近似線分の本数が著しく増大する不
都合が生じるためかなり長めに設定しておく必要があ
る。一方、本発明によれば、予め設定されている許容誤
差よりはるかに小さな角度誤差しか与えない程細分化さ
れた近似線分を発生し、これらについて角度評価を行っ
て、その累積角度誤差が許容誤差を超える寸前まで、順
次連結併合していくという逆の方法であるため、本来的
に当初の固定線分近似精度は従来法に比べて極めて小さ
く選択しておく必要がある。またいくら小さく設定して
も、カーブが緩やかな箇所においては、後述するよう
に、いくらでも連結しておけるために、極めて広い範囲
にわたる長さの線分を発生することができ、最終的なデ
ータの冗長性を著しく低減することができる。すなわ
ち、固定長近似線分の長さを従来方法よりかなり短めに
設定する。For example, in the conventional line segment approximation method, a fixed-length line segment is roughly approximated, and the error distance is evaluated later, and at a place where the error distance is larger than a preset allowable error, , Since the fixed-length line segment before the initial division becomes the approximate line segment with the maximum length due to the sequential division, if it is set too short, the approximate line segment in the gentle curve part Therefore, it is necessary to set the length to a rather long value because the number of lines will increase significantly. On the other hand, according to the present invention, approximate line segments that are subdivided so as to give an angle error far smaller than a preset allowable error are generated, and the angle evaluation is performed for these, and the accumulated angular error is allowed. Since this is the reverse method of sequentially merging and merging just before the error is exceeded, it is necessary to originally select the initial approximation accuracy of the fixed line segment to be extremely smaller than that of the conventional method. In addition, no matter how small the setting is, in a place where the curve is gentle, as will be described later, as many lines as possible can be connected, so line segments with an extremely wide range can be generated, and the final data Redundancy can be significantly reduced. That is, the fixed-length approximate line segment is set to be considerably shorter than the conventional method.
【００１５】このようにして、発生した固定長線分列
は、すでに当該ドットイメージの輪郭を再現するのに十
分すぎる精度をもっているが、輪郭形状の緩慢な曲線部
または直線部においては、極めて冗長度の高いものとな
り、データ量が膨大なものとなる点で好ましくない。In this way, the generated fixed-length line segment sequence is already accurate enough to reproduce the contour of the dot image, but extremely redundant in the curved portion or straight portion of the contour shape. And the amount of data becomes enormous, which is not preferable.
【００１６】そこで、本発明では、連続する２本の固定
長線分の角度を算出し、角度評価部により評価し、評価
の結果によってベクトル合成部にてこれらのベクトル和
を取った１本の可変長近似線分に合成することにより、
データ量の低減を図るものである。Therefore, in the present invention, the angle of two continuous fixed length line segments is calculated, evaluated by the angle evaluation unit, and the vector combining unit calculates the sum of these vectors according to the evaluation result. By synthesizing into a long approximate line segment,
This is intended to reduce the amount of data.
【００１７】連続する２本の固定長線分の角度の角度、
すなわち、基準線分と隣接線分の角度を算出する方法
は、図２に示したように、基準線分の延長線と隣接線分
の角度θを算出してもよく、基準線分と隣接線分の角度
θ’を算出してもよい。The angle between two consecutive fixed length line segments,
That is, in the method of calculating the angle between the reference line segment and the adjacent line segment, the extension line of the reference line segment and the angle θ of the adjacent line segment may be calculated as shown in FIG. The angle θ ′ of the line segment may be calculated.
【００１８】角度θ、θ’を算出する方法は、特に限定
されないが、例えばθを算出する場合は、（１）式によ
り、θ’を算出する場合は、（２）式により求めればよ
い。The method of calculating the angles θ and θ ′ is not particularly limited. For example, when θ is calculated, it may be calculated by the equation (1), and when θ ′ is calculated, it may be calculated by the equation (2).
【００１９】[0019]
【数１】 [Equation 1]
【００２０】角度を計算する方法は、上記（１）式、
（２）式のように逆三角関数を用いる以外にも、各種の
公知な代数計算による近似計算処理を行ってもよい。The method of calculating the angle is as follows:
Instead of using the inverse trigonometric function as in the equation (2), an approximate calculation process by various known algebraic calculations may be performed.
【００２１】角度評価部にはあらかじめ、角度の種類に
応じて許容値を設定しておき、この許容値と算出した角
度を比較評価する。許容値は、角度が基準線分の延長線
と隣接線分との角度θか、基準線分と隣接線分の角度
θ’かによって、異なる。例えば、許容値を以下のよう
に、 （１）基準線分の延長線と隣接線分との角度θの場合の
許容値：１度〜１２度 （２）基準線分と隣接線分の角度θ’の場合の許容値：
１７９度〜１６８度 の範囲内で任意に設定し、許容値の種類により、以下の
ように評価すればよい。An allowable value is set in advance in the angle evaluation unit according to the type of angle, and the calculated value and the allowable value are compared and evaluated. The allowable value differs depending on whether the angle is the angle θ between the extension line of the reference line segment and the adjacent line segment or the angle θ ′ between the reference line segment and the adjacent line segment. For example, the allowable values are as follows: (1) Allowable value in the case of the angle θ between the extension line of the reference line segment and the adjacent line segment: 1 degree to 12 degrees (2) The angle between the reference line segment and the adjacent line segment Allowable value for θ ':
It may be set arbitrarily within the range of 179 degrees to 168 degrees, and may be evaluated as follows according to the type of allowable value.
【００２２】すなわち、算出する角度が基準線分の延長
線と隣接線分の角度θである場合は、角度θが許容値よ
り小さいときは、基準線分と隣接線分が直線近似できる
と評価し、ベクトル合成部で基準線分と隣接線分のベク
トル和をとり、角度θが許容値を超える場合は、基準線
分と隣接線分が直線近似できないと評価し、隣接線分を
基準線分と設定する。That is, when the angle to be calculated is the extension line of the reference line segment and the angle θ of the adjacent line segment, it is evaluated that the reference line segment and the adjacent line segment can be linearly approximated when the angle θ is smaller than the allowable value. Then, the vector composition unit calculates the vector sum of the reference line segment and the adjacent line segment, and if the angle θ exceeds the allowable value, it is evaluated that the reference line segment and the adjacent line segment cannot be linearly approximated, and the adjacent line segment is set to the reference line. Set as minutes.
【００２３】算出する角度が基準線分と隣接線分の角度
θ’である場合は、角度θ’が許容値よりθ’が大きい
ときは、基準線分と隣接線分が直線近似できると評価
し、ベクトル合成部で基準線分と隣接線分のベクトル和
をとり、角度θ’が許容値を超えない場合は、基準線分
と隣接線分が直線近似できないと評価し、隣接線分を基
準線分と設定する。When the angle to be calculated is the angle θ ′ between the reference line segment and the adjacent line segment, it is evaluated that the reference line segment and the adjacent line segment can be linearly approximated when θ ′ is larger than the allowable value. Then, the vector composition unit calculates the vector sum of the reference line segment and the adjacent line segment, and if the angle θ'does not exceed the allowable value, it is evaluated that the reference line segment and the adjacent line segment cannot be linearly approximated, and the adjacent line segment is calculated. Set as a reference line segment.
【００２４】図３により、角度の算出法が基準線分の延
長線と隣接線分の角度θを求める場合の、３本の固定長
線分を近似する方法を例示する。FIG. 3 exemplifies a method of approximating three fixed length line segments in the case where the angle calculation method obtains the extension line of the reference line segment and the angle θ of the adjacent line segment.
【００２５】まず、図３（ａ）に示したように、基準線
分Ｌ1とそれに隣接する隣接線分Ｌ2の角度θ1を求め、
θ1が許容値より小さい場合は、図３（ｂ）に示したよ
うに、基準線分Ｌ1と隣接線分Ｌ2のベクトル和を取り、
ベクトル線分Ｌ1-2を生成する。次に、図３（ｃ）に示
したようにベクトル線分Ｌ1-2を基準線分とし、それに
隣接する隣接線分Ｌ3との角度θ2を求め、θ2が許容値
より小さい場合は、図３（ｄ）に示したように、ベクト
ル線分Ｌ1-2と隣接線分Ｌ3とのベクトル和を取り、ベク
トル線分Ｌ1-3を生成する。これらの動作を近似が終了
するまで繰り返すことにより、ドットイメージの輪郭を
可変長線分で近似することができる。First, as shown in FIG. 3 (a), the angle θ 1 between the reference line segment L 1 and the adjacent line segment L 2 adjacent to it is determined,
When θ 1 is smaller than the allowable value, the vector sum of the reference line segment L 1 and the adjacent line segment L 2 is calculated as shown in FIG.
A vector line segment L 1-2 is generated. Next, a vector line segment L 1-2 as shown in FIG. 3 (c) as a reference line segment, determine the angle theta 2 between the adjacent line segments L 3 adjacent thereto, when theta 2 is smaller than the allowable value , as shown in FIG. 3 (d), taking the vector sum of the adjacent segment L 3 and vector line segment L 1-2, and generates a vector line segment L 1-3. By repeating these operations until the approximation is completed, the contour of the dot image can be approximated by the variable length line segment.
【００２６】もし、連続した固定長近似線分の角度θn
が許容値より小さい場合は、ベクトル合成により１本の
近似線分に合成され続けることになる。If the fixed fixed-length approximate line segment angle θ n
If is smaller than the allowable value, the vector composition continues to be combined into one approximate line segment.
【００２７】なお、ベクトル合成部でベクトル合成を行
うには、図２に示したように、単純にＶ＋ｖ＝（Ｘ＋
ｘ，Ｙ＋ｙ）を実行すればよい。In order to perform vector composition in the vector composition unit, as shown in FIG. 2, simply V + v = (X +
x, Y + y) may be executed.
【００２８】[0028]
【実施例】以下、実施例により本発明をより詳細に説明
する。The present invention will be described in more detail with reference to the following examples.
【００２９】図４は、本発明の線分近似方式の一例を示
すブロック図である。FIG. 4 is a block diagram showing an example of the line segment approximation method of the present invention.
【００３０】１は、原ドットイメージの輪郭を固定長線
分で高精度に分割する輪郭分割部であり、２は基準線分
と隣接線分の角度を算出する角度算出部であり、３は角
度算出部により算出された角度を評価する角度評価部で
あり、４は基準線分と隣接線分の角度が許容値を超える
場合に基準線分と隣接線分のベクトル和を求めベクトル
線分を発生させるベクトル合成部である。Reference numeral 1 is a contour dividing unit for dividing the contour of the original dot image with fixed long line segments with high precision, 2 is an angle calculation unit for calculating an angle between the reference line segment and an adjacent line segment, and 3 is an angle. An angle evaluation unit that evaluates the angle calculated by the calculation unit. Reference numeral 4 indicates a vector sum of vector line segments and adjacent line segments when the angle between the reference line segment and the adjacent line segment exceeds an allowable value. It is a vector synthesis unit to be generated.
【００３１】輪郭分割部１は、原ドットイメージデータ
を、輪郭線上の各点から、半径＝固定長線分の円周と輪
郭線の交点を求めることによって、輪郭線の凸部（凹
部）における内接（外接）多角形を構成することにより
固定長線分で高精度に分割する。角度算出部２は、基準
線分と隣接線分の角度を、前記（１）式または（２）式
により算出する。角度評価部４には、上述した範囲内に
予め許容値を設定しておく。算出した角度が（１）式の
θの場合は、上記許容値よりθが小さいときは、ベクト
ル合成部４で基準線分と隣接線分のベクトル和を取り、
算出した角度が（２）式のθ’の場合は、上記許容値よ
りθ’が大きいときに、ベクトル合成部４で基準線分と
隣接線分のベクトル和を取ればよい。The contour dividing unit 1 obtains the original dot image data from the points on the contour line by finding the intersection point of the contour of the radius = fixed length line segment and the contour line, and thus the inside of the convex portion (concave portion) of the contour line. By constructing a tangent (circumscribing) polygon, a fixed-length line segment is divided with high precision. The angle calculation unit 2 calculates the angle between the reference line segment and the adjacent line segment by the equation (1) or the equation (2). The angle evaluation unit 4 has an allowable value set in advance within the above range. When the calculated angle is θ in the equation (1), and when θ is smaller than the above-mentioned allowable value, the vector combining unit 4 takes the vector sum of the reference line segment and the adjacent line segment,
When the calculated angle is θ ′ in the equation (2), when θ ′ is larger than the allowable value, the vector combining unit 4 may take the vector sum of the reference line segment and the adjacent line segment.
【００３２】ベクトル合成部４は、基準線分と隣接線分
のベクトル和を取り、ベクトル線分を生成する。The vector synthesizing unit 4 takes the vector sum of the reference line segment and the adjacent line segment to generate a vector line segment.
【００３３】図５は、本発明の一実施例を示すフローチ
ャートである。なお、基準線分と隣接線分から求める角
度は、前記（１）式により算出されるものである。FIG. 5 is a flow chart showing an embodiment of the present invention. The angle obtained from the reference line segment and the adjacent line segment is calculated by the equation (1).
【００３４】Ｓ１：ドットイメージの輪郭を固定長線分
で高精度に分割する。分割する方法は、原ドットイメー
ジデータを、輪郭線上の各点から、半径＝固定長線分の
円周と輪郭線の交点を求めることによって、輪郭線の凸
部（凹部）における内接（外接）多角形を構成すること
により固定長線分で高精度に分割する方法により行えば
よい。S1: The contour of the dot image is accurately divided into fixed length line segments. The method of dividing the original dot image data is to inscribe (outer) the convex portion (concave portion) of the contour line by finding the intersection point of the contour of the radius = fixed length line segment from each point on the contour line. It may be performed by a method of dividing a fixed length line segment with high accuracy by forming a polygon.
【００３５】Ｓ２：基準線分と隣接線分の角度θを、前
記（１）式により算出する。S2: The angle θ between the reference line segment and the adjacent line segment is calculated by the equation (1).
【００３６】Ｓ３：算出したθと予め設定された許容値
を比較する。S3: The calculated θ is compared with a preset allowable value.
【００３７】Ｓ４：θが許容値より大きい場合は、隣接
隣接線分を基準線分とし、Ｓ７へジャンプする。S4: When θ is larger than the allowable value, the adjacent adjacent line segment is set as the reference line segment, and the process jumps to S7.
【００３８】Ｓ５：θが許容値より小さい場合は、基準
線分と隣接線分のベクトル和を合成する。S5: If θ is smaller than the allowable value, the vector sum of the reference line segment and the adjacent line segment is combined.
【００３９】Ｓ６：合成されたベクトル線分を基準線分
とする。S6: The synthesized vector line segment is used as a reference line segment.
【００４０】Ｓ７：線分近似が終了したどうかを判定す
る。終了判定としては、例えば本発明方法によれば、輪
郭形状の近似線分のｘ成分とｙ成分の合成を累積してゆ
けば、終点においては必ず両者とも０になることから、
これを以て１輪郭分の線分近似の終了を判定する等の方
法による。線分近似がまだ終了していない場合は、Ｓ２
へもどり、線分近似が終了している場合は、プログラム
エンドとなる。S7: It is judged whether the line segment approximation is completed. As the end determination, for example, according to the method of the present invention, when the synthesis of the x component and the y component of the approximate line segment of the contour shape is accumulated, both are always 0 at the end point,
Based on this, a method such as determining the end of the line segment approximation of one contour is used. If the line segment approximation is not yet finished, S2
If the line returns and the line segment approximation is completed, the program ends.
【００４１】[0041]
【発明の効果】本発明の方法および方式により、以下の
ような優れた効果が得られる。According to the method and system of the present invention, the following excellent effects can be obtained.
【００４２】（１）高速な誤差評価による高速線分近似
ができるので、従来膨大な時間を要していたドットイメ
ージから直線アウトラインフォントの生成が、極めて短
時間に行えるようになる。(1) Since high-speed line segment approximation can be performed by high-speed error evaluation, it is possible to generate a straight-line outline font from a dot image, which has conventionally required a huge amount of time, in an extremely short time.
【００４３】（２）近似線分の長さのレンジが原理的に
広い（長い方にはいくらでも伸びられる）ため、従来の
線分近似方法に比して、極めて高効率のデータ圧縮効果
が得られる。(2) Since the range of the length of the approximated line segment is wide in principle (it can be extended to the longer one as much as possible), a highly efficient data compression effect can be obtained as compared with the conventional line segment approximation method. To be
【００４４】（３）近似線分の長さのレンジが原理的に
広いため、実用的な再現拡大率の範囲において、曲線近
似に劣らないドット復元品質が保証される。(3) Since the range of the length of the approximate line segment is theoretically wide, the dot restoration quality is as good as the curve approximation in the range of the practical reproduction enlargement ratio.
【００４５】（４）角度計算式において、数学的に豊富
な近似掲載方法があり、逆三角関数を計算する必要がか
ならずしもなく、単純な代数計算で更に高速化が可能と
なる。(4) In the angle calculation formula, there are mathematically rich approximation posting methods, and it is not always necessary to calculate the inverse trigonometric function, and the speed can be further increased by simple algebraic calculation.
【００４６】（５）ドット復元計算時において、曲線近
似方法に比べて極めて高速な処理が可能となる。(5) In the dot restoration calculation, extremely high speed processing is possible as compared with the curve approximation method.
【図面の簡単な説明】[Brief description of drawings]
【図１】基準線分と隣接線分の角度の説明図。FIG. 1 is an explanatory diagram of an angle between a reference line segment and an adjacent line segment.
【図２】ドットイメージの輪郭を固定長線分で分割する
説明図。FIG. 2 is an explanatory diagram of dividing a contour of a dot image into fixed-length line segments.
【図３】（ａ），（ｂ），（ｃ），（ｄ）は、基準線分
と隣接線分のベクトル和を合成する説明図。3 (a), (b), (c), and (d) are explanatory diagrams for synthesizing vector sums of reference line segments and adjacent line segments.
【図４】本発明の一実施例を示すブロック図。FIG. 4 is a block diagram showing an embodiment of the present invention.
【図５】本発明の一実施例を示すフローチャート。FIG. 5 is a flowchart showing an embodiment of the present invention.
【図６】従来の、直線近似方法の説明図。FIG. 6 is an explanatory diagram of a conventional linear approximation method.
１ 輪郭分割部 ２ 角度算出部 ３ 角度評価部 ４ ベクトル合成部 1 contour division unit 2 angle calculation unit 3 angle evaluation unit 4 vector synthesis unit
Claims (2)
法において、原ドットイメージの輪郭を固定長線分で高
精度に分割し、基準線分と隣接線分の角度を算出し、算
出した角度を評価し、基準線分と隣接線分を直線近似で
きると評価した場合は、基準線分と隣接線分のベクトル
和を求めベクトル線分を発生させて、ベクトル線分を基
準線分とし、基準線分と隣接線分を直線近似できないと
評価した場合は、隣接線分を基準線分とし、ドットイメ
ージの分割点の最終点に至るまで繰り返すことを特徴と
するドットイメージデータの輪郭の線分近似方法。1. A method of approximating a contour of a dot image by a line segment, in which the contour of an original dot image is accurately divided by a fixed length line segment, an angle between a reference line segment and an adjacent line segment is calculated, and the calculated angle is calculated. If it is evaluated that the reference line segment and the adjacent line segment can be linearly approximated, the vector line segment is generated by obtaining the vector sum of the reference line segment and the adjacent line segment, and the vector line segment is used as the reference line segment. When it is evaluated that the line segment and the adjacent line segment cannot be linearly approximated, the adjacent line segment is used as the reference line segment, and the line segment of the outline of the dot image data is characterized by repeating until the final point of the dot image division points. Approximation method.
式において、原ドットイメージの輪郭を固定長線分で高
精度に分割する輪郭分割部と、基準線分と隣接線分の角
度を算出する角度算出部と、角度算出部により算出され
た角度を評価する角度評価部と、基準線分と隣接線分の
ベクトル和を求めベクトル線分を発生させるベクトル合
成部とを備え、基準線分と隣接線分を直線近似できると
評価した場合は、基準線分と隣接線分のベクトル和を求
めベクトル線分を発生させてベクトル線分を基準線分と
し、基準線分と隣接線分を直線近似できないと評価した
場合は、隣接線分を基準線分とし、ドットイメージの分
割点の最終点に至るまで繰り返すように構成したことを
特徴とするドットイメージデータの輪郭の線分近似方
式。2. In a method of approximating the contour of a dot image by a line segment, a contour dividing unit that accurately divides the contour of an original dot image by a fixed-length line segment, and an angle for calculating an angle between a reference line segment and an adjacent line segment. A calculation unit, an angle evaluation unit that evaluates the angle calculated by the angle calculation unit, and a vector synthesis unit that generates a vector line segment by obtaining the vector sum of the reference line segment and the adjacent line segment and are adjacent to the reference line segment. If it is evaluated that the line segment can be linearly approximated, the vector sum of the reference line segment and the adjacent line segment is calculated to generate the vector line segment, and the vector line segment is set as the reference line segment, and the reference line segment and the adjacent line segment are linearly approximated. If it is judged that the dot image data cannot be obtained, the line segment approximation method for the contour of the dot image data is characterized in that the adjacent line segment is used as a reference line segment and is repeated until the end point of the division points of the dot image.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP505595A JPH08194816A (en) | 1995-01-17 | 1995-01-17 | Segment approximation method and its system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP505595A JPH08194816A (en) | 1995-01-17 | 1995-01-17 | Segment approximation method and its system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08194816A true JPH08194816A (en) | 1996-07-30 |
Family
ID=11600722
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP505595A Pending JPH08194816A (en) | 1995-01-17 | 1995-01-17 | Segment approximation method and its system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08194816A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004063986A1 (en) * | 2003-01-14 | 2004-07-29 | Max Co., Ltd | Image correction program, driver program, image output device, cutting system, and cutting machine |
| JP2006027181A (en) * | 2004-07-20 | 2006-02-02 | Canon Inc | Ink-jet recorder, ink-jet recording method and computer program |
| US7031514B1 (en) | 1999-08-27 | 2006-04-18 | Celartem Technology Inc. | Image compression method |
| JP2009199340A (en) * | 2008-02-21 | 2009-09-03 | Fuji Xerox Co Ltd | Data processing device, affiliated data-generating device, data processing program, affiliated data generating program |
| JP2010074275A (en) * | 2008-09-16 | 2010-04-02 | Konica Minolta Business Technologies Inc | Outlining method, image compression method using the same, outlining device, and outlining program |
-
1995
- 1995-01-17 JP JP505595A patent/JPH08194816A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7031514B1 (en) | 1999-08-27 | 2006-04-18 | Celartem Technology Inc. | Image compression method |
| WO2004063986A1 (en) * | 2003-01-14 | 2004-07-29 | Max Co., Ltd | Image correction program, driver program, image output device, cutting system, and cutting machine |
| JP2006027181A (en) * | 2004-07-20 | 2006-02-02 | Canon Inc | Ink-jet recorder, ink-jet recording method and computer program |
| JP2009199340A (en) * | 2008-02-21 | 2009-09-03 | Fuji Xerox Co Ltd | Data processing device, affiliated data-generating device, data processing program, affiliated data generating program |
| JP2010074275A (en) * | 2008-09-16 | 2010-04-02 | Konica Minolta Business Technologies Inc | Outlining method, image compression method using the same, outlining device, and outlining program |
| JP4600552B2 (en) * | 2008-09-16 | 2010-12-15 | コニカミノルタビジネステクノロジーズ株式会社 | Outline conversion method, image compression method using the same, outline conversion apparatus, and outline conversion program |
| US8553294B2 (en) | 2008-09-16 | 2013-10-08 | Konica Minolta Business Technologies, Inc. | Outlining method for properly representing curved line and straight line, and image compression method using the same |
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