fixed articles
"In another guide titled [How U-net Works](https://developers.arcgis.com/python/guide/how-unet-works/), we saw how to achieve pixel level classification that helps in solving problems like land cover classification. Algorithms achieving tasks like this are categorized as **Semantic Segmentation**. \n",
"\n",
"**Object Instance Segmentation** is a recent approach that gives us best of both worlds. \n",
- "It integrates object detection task where the goal is to detect object class along with bounding box prediction in an image and semantic segmentation task, which classifies each pixel into pre-defined categories Thus, it enables us to detect objects in an image while precisely segmenting mask for each object instance. \n",
+ "It integrates object detection task where the goal is to detect object class along with bounding box prediction in an image and semantic segmentation task, which classifies each pixel into pre-defined categories Thus, it enables us to detect objects in an image while precisely segmenting a mask for each object instance. \n",
"\n",
- "Instance segmentation allows us to solve problems like damage detection where it's important to know extent of damage. Another use case is in case of Self Driving Cars where it's important to know position of each car in the scene. Generating building footprints for each individual building is a popular problem in the field of GIS. `arcgis.learn` gives us advantage to use Mask R-CNN model to solve such real life problems. \n",
+ "Instance segmentation allows us to solve problems like damage detection where it's important to know extent of damage. Another use case is in case of self driving cars where it's important to know position of each car in the scene. Generating building footprints for each individual building is a popular problem in the field of GIS. `arcgis.learn` gives us advantage to use Mask R-CNN model to solve such real life problems. \n",
"\n",
"Let us take an example of building footprint detection use case. "
]
"cell_type": "markdown",
"metadata": {},
"source": [
- "Mask R-CNN is a state of the art model for instance segmentation, developed on top of Faster R-CNN. Faster R-CNN is region-based convolutional neural networks [2], that returns bounding boxes of each object and its class label with confidence score.\n",
+ "Mask R-CNN is a state of the art model for instance segmentation, developed on top of Faster R-CNN. Faster R-CNN is a region-based convolutional neural networks [2], that returns bounding boxes for each object and its class label with a confidence score.\n",
"\n",
"To understand Mask R-CNN, let's first discus architecture of Faster R-CNN that works in two stages:\n",
"\n",
- "**Stage1**: The first stage consists of two networks, backbone (ResNet, VGG, Inception, etc..) and region proposal network. These networks run once per image to give set of region proposals. Region proposals is the region in feature map which contains object.\n",
+ "**Stage1**: The first stage consists of two networks, backbone (ResNet, VGG, Inception, etc..) and region proposal network. These networks run once per image to give a set of region proposals. Region proposals are regions in the feature map which contain the object.\n",
"\n",
"**Stage2**: In the second stage, the network predicts bounding boxes and object class for each of the proposed region obtained in stage1. Each proposed region can be of different size whereas fully connected layers in the networks always require fixed size vector to make predictions. Size of these proposed regions is fixed by using either RoI pool (which is very similar to MaxPooling) or RoIAlign method.\n"
]
