text_line_orientationtext_line_orientationTextLineOrientationTextLineOrientationtext_line_orientation (算子)

名称

text_line_orientationtext_line_orientationTextLineOrientationTextLineOrientationtext_line_orientation — 确定文本行或段落的方向。

签名

text_line_orientation(Region, Image : : CharHeight, OrientationFrom, OrientationTo : OrientationAngle)

描述

text_line_orientationtext_line_orientationTextLineOrientationTextLineOrientationTextLineOrientationtext_line_orientation determines the orientation of a single text line or a paragraph in relation to the horizontal image axis. If the orientation of a single text line should be determined, the range for the OrientationFromOrientationFromOrientationFromOrientationFromorientationFromorientation_from and OrientationToOrientationToOrientationToOrientationToorientationToorientation_to should be in the interval from -pi/4 to pi/4.

The parameter RegionRegionRegionRegionregionregion specifies the area of the image in which the text lines are located. The RegionRegionRegionRegionregionregion is only used to reduce the working area. To determine the slant, the gray values inside that area are used. The text lines are segmented by the operator text_line_orientationtext_line_orientationTextLineOrientationTextLineOrientationTextLineOrientationtext_line_orientation itself. If more than one region is passed, the numerical values of the orientation angle are stored in a tuple, the position of a value in the tuple corresponding to the position of the region in the input tuple.

CharHeightCharHeightCharHeightCharHeightcharHeightchar_height specifies the approximately height of the existing text lines in the region RegionRegionRegionRegionregionregion. It's assumed, that the text lines are darker than the background.

The search area can be restricted by the parameters OrientationFromOrientationFromOrientationFromOrientationFromorientationFromorientation_from and OrientationToOrientationToOrientationToOrientationToorientationToorientation_to, whereby also the runtime of the operator is influenced.

With the calculated angle OrientationAngleOrientationAngleOrientationAngleOrientationAngleorientationAngleorientation_angle and operators like affine_trans_imageaffine_trans_imageAffineTransImageAffineTransImageAffineTransImageaffine_trans_image, the region RegionRegionRegionRegionregionregion of the image ImageImageImageImageimageimage can be rotated such, that the text lines lie horizontally in the image. This may simplify the character segmentation for OCR applications.

执行信息

多线程类型：可重入（与非独占算子并行运行）。
多线程作用域：全局（可从任何线程调用）。
在元组级别上自动并行化。

参数

RegionRegionRegionRegionregionregion (输入对象) region(-array) → object

Area of text lines.

ImageImageImageImageimageimage (输入对象) singlechannelimage → object (byte / uint2)

输入图像。

CharHeightCharHeightCharHeightCharHeightcharHeightchar_height (输入控制) integer → (integer)

Height of the text lines.

默认值： 25

值范围： 1 ≤ CharHeight CharHeight CharHeight CharHeight charHeight char_height

限制： CharHeight >= 1

OrientationFromOrientationFromOrientationFromOrientationFromorientationFromorientation_from (输入控制) angle.rad → (real)

Minimum rotation of the text lines.

默认值： -0.523599

值范围： -3.141593 ≤ OrientationFrom OrientationFrom OrientationFrom OrientationFrom orientationFrom orientation_from ≤ 3.141593

限制： OrientationFrom <= OrientationTo

OrientationToOrientationToOrientationToOrientationToorientationToorientation_to (输入控制) angle.rad → (real)

Maximum rotation of the text lines.

默认值： 0.523599

值范围： -3.141593 ≤ OrientationTo OrientationTo OrientationTo OrientationTo orientationTo orientation_to ≤ 3.141593

限制： OrientationFrom <= OrientationTo && OrientationTo < OrientationFrom + pi

OrientationAngleOrientationAngleOrientationAngleOrientationAngleorientationAngleorientation_angle (输出控制) angle.rad(-array) → (real)

Calculated rotation angle of the text lines.

示例（HDevelop）

read_image(Image,'letters')
text_line_orientation(Image,Image,50,rad(-80),rad(80),OrientationAngle)
rotate_image(Image,ImageRotate,-OrientationAngle/rad(180)*180,'constant')

结果

If the input parameters are set correctly, the operator text_line_orientationtext_line_orientationTextLineOrientationTextLineOrientationTextLineOrientationtext_line_orientation 返回值 2 ( H_MSG_TRUE )。否则将抛出异常。

可能的后继

rotate_imagerotate_imageRotateImageRotateImageRotateImagerotate_image, affine_trans_imageaffine_trans_imageAffineTransImageAffineTransImageAffineTransImageaffine_trans_image, affine_trans_image_sizeaffine_trans_image_sizeAffineTransImageSizeAffineTransImageSizeAffineTransImageSizeaffine_trans_image_size

模块

基础

算子