Reading PCM Files: File Format for Storing Real Optical Flow Fields

PCM files serve as a specialized format for storing real optical flow field data, playing a significant role in computer vision and image processing applications. Optical flow fields capture the motion patterns of pixels over time in image sequences, forming fundamental data for motion analysis, object tracking, and related tasks.

The implementation approach for reading PCM files in MATLAB involves several key steps. First, understanding the file structure and storage format is essential - typically these binary files store horizontal and vertical components of optical flow fields in a specific sequence. The reading process requires opening the file in binary mode using fopen() with 'rb' permission, then reading numerical values according to predefined data formats (such as single-precision floating-point numbers) using fread() function. Proper data type specification in fread() ensures accurate interpretation of binary data.

During data processing phase, the raw binary data needs conversion into MATLAB matrix format. Since optical flow fields contain motion information in both horizontal and vertical directions, the data is typically reshaped into two 2D matrices using reshape() function - one representing x-direction flow components and the other y-direction components. To ensure data integrity, file size validation should be performed by comparing actual file size with expected dimensions (height × width × 2 components × bytes per value), preventing reading errors due to file corruption.

This custom file format reading method offers higher efficiency compared to general image formats, enabling direct processing of floating-point precision optical flow data while avoiding compression artifacts and type conversion issues common in standard image formats. For subsequent optical flow visualization or analysis tasks, the read data can be directly utilized in algorithms or visualized using functions like quiver() for vector field display, providing immediate compatibility with MATLAB's computer vision toolbox operations.