Answers.Body: <p>With <em>Bounding box</em> people usually mean literally the box which bounds something. So, more intuitive way to use the points in the first case as bottom left and top right points and in the second case bottom left point and sizes. This corresponds to the logic of points on the Cartesian grid.
  Of course, you may reverse sometimes against Y axis in case your task requires so. For example, some software has X origin at top left corner of the monitor. In this case, sometimes y subscripts can reverse.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-09-21T00:49:31.527Z
Answers.LastActivityDate: 2021-09-21T00:49:31.527Z
Answers.UserDisplayName: Damir Tenishev
Answers.Body: <p><span class="math-container">$(x_1, y_1)$</span> or <span class="math-container">$(x_{min}, y_{min})$</span> generally refers to the coordinate of the top-left of the bounding box, as the x-coordinate goes from left to right and the y-coordinate goes from top to bottom in computer-vision.</p>
  <p>However, note that the bounding box coordinate labeling may be different depending on what convention the dataset/model is following.</p>
  <p>For pascal_voc convention, this is <span class="math-container">$(x_{min}, y_{min}, x_{max}, y_{max})$</span></p>
  <p>For coco convention, this is <span class="math-container">$(x_{min}, y_{min}, \text{width}, \text{height})$</span></p>
  <p>For yolo, this is <span class="math-container">$(x_{center}, y_{center}, \text{width}, \text{height})$</span> <strong>normalized</strong></p>
  <p>You may refer to the below link for more details
  <a href="https://albumentations.ai/docs/getting_started/bounding_boxes_augmentation/" rel="nofollow noreferrer">https://albumentations.ai/docs/getting_started/bounding_boxes_augmentation/</a></p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-10-17T05:44:05.587Z
Answers.LastActivityDate: 2022-10-17T06:07:07.277Z
Answers.LastEditDate: 2022-10-17T06:07:07.277Z
Answers.UserDisplayName: PeaBrane
Body: <p>For the image datasets, there may be a bounding box for each image at the dataset. It is an annotation for an image. It is a rectangular box intended for focusing on something inside the image.</p>
  <p>I read about the following two types of representations for a bounding box.</p>
  <ol>
  <li>using two points <span class="math-container">$(x_1, y_1)$</span> and <span class="math-container">$(x_2, y_2)$</span>.</li>
  </ol>
  <p><span class="math-container">$$&lt;x_1&gt;&lt;y_1&gt;&lt;x_2&gt;&lt;y_2&gt;$$</span></p>
  <ol start="2">
  <li>Using a point <span class="math-container">$(x_1, y_1)$</span>, width, and height.
  <span class="math-container">$$&lt;x_1&gt;&lt;y_1&gt;&lt;width&gt;&lt;height&gt;$$</span></li>
  </ol>
  <p>How do understand both the representations, Specifically, does the point <span class="math-container">$(x_1, y_1)$</span> used to denote the top right or top left or bottom right or bottom left in both cases?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-09-20T10:39:35.653Z
Comments.Text: In case 2 it could also be the centre, ie the box starts at (x - (w/2)) and end at (x+(w/2)) etc.
Comments.UserDisplayName: Oliver Mason
Tags: <image-processing><bounding-box>
Title: How to understand the common practices followed for writing a "bounding box" for an image in datasets?
UserDisplayName: hanugm
ThreadText: # How to understand the common practices followed for writing a "bounding box" for an image in datasets?
  
  (Asked by: username_0 on 2021-09-20)
  
  For the image datasets, there may be a bounding box for each image at the dataset. It is an annotation for an image. It is a rectangular box intended for focusing on something inside the image.
  
  I read about the following two types of representations for a bounding box.
  
  1. using two points $(x\_1, y\_1)$ and $(x\_2, y\_2)$.
  
  $$<x\_1><y\_1><x\_2><y\_2>$$
  
  2. Using a point $(x\_1, y\_1)$, width, and height.
     $$<x\_1><y\_1><width><height>$$
  
  How do understand both the representations, Specifically, does the point $(x\_1, y\_1)$ used to denote the top right or top left or bottom right or bottom left in both cases?
  
  **Tags:** image-processing, bounding-box
  
  > **Comments:**
  > **username_1**: In case 2 it could also be the centre, ie the box starts at (x - (w/2)) and end at (x+(w/2)) etc.  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_2 on 2021-09-21. Score: 0
  
  With *Bounding box* people usually mean literally the box which bounds something. So, more intuitive way to use the points in the first case as bottom left and top right points and in the second case bottom left point and sizes. This corresponds to the logic of points on the Cartesian grid.
  Of course, you may reverse sometimes against Y axis in case your task requires so. For example, some software has X origin at top left corner of the monitor. In this case, sometimes y subscripts can reverse.
  
  
  ---
  
  ### Answer by username_3 on 2022-10-17. Score: 0
  
  $(x\_1, y\_1)$ or $(x\_{min}, y\_{min})$ generally refers to the coordinate of the top-left of the bounding box, as the x-coordinate goes from left to right and the y-coordinate goes from top to bottom in computer-vision.
  
  However, note that the bounding box coordinate labeling may be different depending on what convention the dataset/model is following.
  
  For pascal\_voc convention, this is $(x\_{min}, y\_{min}, x\_{max}, y\_{max})$
  
  For coco convention, this is $(x\_{min}, y\_{min}, \text{width}, \text{height})$
  
  For yolo, this is $(x\_{center}, y\_{center}, \text{width}, \text{height})$ **normalized**
  
  You may refer to the below link for more details
  <https://albumentations.ai/docs/getting_started/bounding_boxes_augmentation/>
  
  
  ---
  
  