How can I rectify images

2017 2 4
1 个回答
回答已采纳
更新时间：2022 11 21
12 次查看（30 天）

1 个投票

Hi all,
Interesting problem here. I am working on extracting old Chinese texts which are written in vertical lines, but first I need to rectify the images like:
After rectification:
But originally they can be in whatever shapes like:
The only thing guaranteed is that those characters are arranged in multiple vertical lines.
I tried to use Uncalibrated Stereo Image Rectification ( https://www.mathworks.com/help/vision/examples/uncalibrated-stereo-image-rectification.html ), but problem is that the images are NOT in pair, so I only know the target pattern rather than the exact target.
If anyone can provide hints about useful functions, please let me know. First-step solutions like automatically rotating the image to the right angle will also be helpful!
Thanks a lot!

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

Image Analyst
Image Analyst 2017-2-4
Why don't you have control over the image capture situation? If someone is wanting OCR on these books and manuscripts you'd think they would take more care in how they are photographed.

请先登录，再进行评论。

请先登录，再回答此问题。

 采纳的回答

Carl
Carl 2017-2-7
编辑：Carl 2017-2-7

1 个投票

From what I understand, your two main issues are 1) detecting the text in your images, and 2) perspective correction.
You can refer to the following page on detecting and recognizing text in images:
https://www.mathworks.com/help/vision/examples/automatically-detect-and-recognize-text-in-natural-images.html
As well as this File Exchange submission that gives an example on how to perform perspective correction on a bounded area of text:
https://www.mathworks.com/matlabcentral/fileexchange/35531-perspective-control--correction
(This Wikipedia page might be a good starting point as well)

3 个评论
显示 1更早的评论 隐藏 1更早的评论

Zhen Hu
Zhen Hu 2017-2-7
Thanks a lot, Carl.
The perspective control submission is really impressive and definitely a thing I will try to incorporate. For the specific task I will not go as far as OCR since an image-to-image transform suffices.
The automatic text detector is nice though there seem to be bunch of parameters. Will look into that.
Much appreciated!
Carl
Carl 2017-2-7
No problem. Also keep in mind that, while it works, the File Exchange submission uses several deprecated functions like "maketform" and "imtransform". These should be replaced with newer functionality like "projective2d" and "imwarp".
xingxingcui
xingxingcui 2022-11-21
In the new version R2022a it is possible to use the deep learning function "detectTextCRAFT" for text detection and in R2022b the pre-multiply form "projtform2d", "imwarp" etc.

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Convert Image Type 的更多信息

产品

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by