An FPGA-implemented Method for Real-time Multi-dimensional Feature Extraction of Sequence Image Targets

The prerequisite of target detection and tracking is to model and represent the target based on multi-dimensional features extracted from the target region. The traditional target feature extraction needs to connect the target region first and then must calculate the target feature, which has still room for improvement in real-time performance. An advantage of the new method based on the synchronous calculation of pixel-connected domain markers and target features is that the target features can be output when the target region is connected. This article proposes a method highlighting pixel-based marking of connection domains and synchronous computation of target features, which can output target features immediately after target areas are connected. By setting up a feature transfer mechanism, this method establishes a marker table, a marker mapping table and a feature attributes table while scanning images, and links the marker mapping table and the feature attributes table with the help of the marker table. When different areas are adjacent to one another, markers are consolidated while the features’ attributes are synchronously transferred and computed, ensuring real-time extraction of the target features. Regarding real-time and multiple-dimensional extraction of the features of multiple targets in high-resolution distant sensing images, the article proposes an implementation plan based on FPGA hardware design. According to the results of a number of simulation tests, the method featuring high-speed marking of connection domains over one iteration of split pixels and real-time computing of target features boasts the following outstanding characteristics: The time consumed by marking connection domains is only (L × W + 2n/m) × T_clk, close to the theoretical minimum (L × W) × T_clk; saving images in cyclical buffers only takes up few resources; parallel pipeline processing of marking and computation improves the detection and tracking efficiency; the test results of multiple target features are accurate and consequently can effectively support subsequent target tracing detections; and the method also has both theoretical and practical values.