什麼是 Azure 自訂視覺服務?What is Azure Custom Vision?

Azure 自訂視覺是一項認知服務,可讓您建置、部署和改善自己的影像分類器。Azure Custom Vision is a cognitive service that lets you build, deploy and improve your own image classifiers. 影像分類器是一項 AI 服務,可根據影像的視覺特性對影像套用標籤 (代表_類別_)。An image classifier is an AI service that applies labels (which represent classes) to images, according to their visual characteristics. 不同於電腦視覺服務,自訂視覺可讓您決定所要套用的標籤。Unlike the Computer Vision service, Custom Vision allows you to determine the labels to apply.

作用What it does

自訂視覺服務會使用機器學習演算法對影像套用標籤。The Custom Vision service uses a machine learning algorithm to apply labels to images. 身為開發人員的您必須提交具備和缺少相關特性的影像群組。You, the developer, must submit groups of images that feature and lack the characteristics in question. 您必須在提交時自行為影像加上標籤。You label the images yourself at the time of submission. 然後,演算法會針對這項資料進行訓練,並藉由對這些相同的影像進行自我測試,計算其本身的精確度。Then the algorithm trains to this data and calculates its own accuracy by testing itself on those same images. 演算法經過訓練後,您可以測試、重新訓練,最終根據您的應用程式需求用它來分類新的影像。Once the algorithm is trained, you can test, retrain, and eventually use it to classify new images according to the needs of your app. 您也可以匯出模型本身以供離線使用。You can also export the model itself for offline use.

分類和物件偵測Classification and object detection

自訂視覺功能可以細分成兩項功能。Custom Vision functionality can be divided into two features. 影像分類會對影像套用一或多個標籤。Image classification applies one or more labels to an image. 物件偵測也相類似,但它還會傳回影像中已套用的標籤所在位置的座標。Object detection is similar, but it also returns the coordinates in the image where the applied label(s) can be found.

最佳化Optimization

自訂視覺服務經過最佳化,可快速辨識影像之間的主要差異。The Custom Vision service is optimized to quickly recognize major differences between images. 如此,您只需要少量資料即可開始建立模型的原型。This allows you to start prototyping your model with a small amount of data. 一般而言,每個標籤 50 個影像是不錯的起點。50 images per label are generally a good start. 但這表示服務並未具備偵測影像中些微差異的最佳效能 (例如,在品保案例中偵測出微小的裂縫或凹痕)。This means, however, that the service is not optimal for detecting subtle differences in images (for example, detecting minor cracks or dents in quality assurance scenarios).

此外,您可以從數種不同針對特定題材內容的影像進行最佳化的自訂視覺演算法中擇一使用—例如,地標或零售項目。Additionally, you can choose from several varieties of the Custom Vision algorithm that are optimized for images with certain subject material—for example, landmarks or retail items. 如需其詳細資訊,請參閱建置分類器指南。See the Build a classifier guide for more information on these.

包含內容What it includes

自訂視覺服務可作為一組的原生 SDK,也可透過自訂視覺服務首頁上的 Web 介面來使用。The Custom Vision Service is available as a set of native SDKs as well as through a web-based interface on the Custom Vision home page. 您可以使用上述一或兩種介面來建立、測試和訓練模型。You can create, test, and train a model through either interface or use both together.

Chrome 瀏覽器視窗中的自訂視覺服務首頁

資料隱私權和安全性Data privacy and security

和所有認知服務一樣,使用自訂視覺服務的開發人員應該要了解 Microsoft 對於客戶資料的政策。As with all of the Cognitive Services, developers using the Custom Vision service should be aware of Microsoft's policies on customer data. 請參閱 Microsoft 信任中心上的認知服務頁面,以進行深入了解。See the Cognitive Services page on the Microsoft Trust Center to learn more.

後續步驟Next steps

請依照建置分類器指南在 Web 上開始使用自訂視覺,或完成影像分類教學課程以使用程式碼實作基本案例。Follow the Build a classifier guide to get started using Custom Vision on the web, or complete an Image classification tutorial to implement a basic scenario in code.