Single Image Liveness

This page describes the single image liveness feature of Liveness.

A Single Image Liveness (or 2D Liveness) Detection is a passive, image-based, monocular liveness check which uses only one RBG image as the input media. The Single Image Liveness in Liveness detects the largest face in an uploaded image and returns the results of the spoof score.

Input media requirements

For a Single Image Liveness detection, there should be one image included in the request body. The image file should meet the following standards.

ItemMinimum requirementRecommended
File sizeUnder 4MB (approximately)200KB
Minimum Pixels of the face32×32200×200
File formatJPG (JPEG), PNG, GIF (The first frame only)JPG (JPEG), PNG
Number of faces in the portraitMore than 11 only

The detection logic is defined to proceed with only one face in the image. But images with multiple faces are acceptable to improve the user experience.


There is currently one model available for Single Image Liveness. Any model improvements will not change its name or the recommended threshold value to address the user's API compatibility. Feel comfortable using the same model name and the recommended threshold value.

Model nameInput mediaRecommended threshold
JCV_2D_I25000images: [0]RGB0.5