Image processing apparatus that generates a tomographic image of a subject based on phase-adjusted measurement signals from which a background signal is subtracted, and related imaging apparatus, image processing method, and computer readable storage medium

An image processing apparatus comprising:

• (A) a memory that stores instructions;
• and
• (B) at least one processor that executes the instructions to function as:
• (a) a measurement signal acquiring unit configured to acquire measurement signals including information on a tomography of a subject in a depth direction obtained by performing optical coherence tomography on the subject;
• (b) a base signal acquiring unit configured to acquire a base signal based on the measurement signals;
• (c) a generating unit configured to generate a background signal corresponding to a noise component based on the measurement signals and the base signal;
• (d) a calculating unit configured to calculate phase shifts between the measurement signals and the background signal;
• (e) a smoothing unit configured to smooth the phase shifts;
• (f) an adjusting unit configured to adjust a phase of the background signal corresponding to the smoothed phase shifts based on the smoothed phase shifts;
• (g) a subtracting unit configured to subtract the phase-adjusted background signal from the measurement signals;
• and
• (h) an image generation unit configured to generate a tomographic image of the subject based on the measurement signals from which the phase-adjusted background signal is subtracted.

An imaging apparatus comprising:

• (A) a measurement optical system configured to split light from a light source into measurement light and reference light, the measurement light being applied to a subject, and to generate measurement signals including information on a tomography of the subject in a depth direction based on interfering light obtained by causing returning light of the measurement light from the subject and the reference light to interfere with each other;
• and
• (B) an image processing apparatus that is connected to the measurement optical system so as to communicate with the measurement optical system, the image processing apparatus comprising:
• (a) a memory that stores instructions;
• and
• (b) at least one processor that executes the instructions to function as:
• (i) a measurement signal acquiring unit configured to acquire the measurement signals from the measurement optical system;
• (ii) a base signal acquiring unit configured to acquire a base signal based on the measurement signals;
• (iii) a calculating unit configured to calculate phase shifts between the measurement signals and the base signal;
• (iv) a smoothing unit configured to smooth the phase shifts;
• (v) an adjusting unit configured to adjust phases of the measurement signals corresponding to the smoothed phase shifts based on the smoothed phase shifts;
• (vi) a generating unit configured to generate a background signal corresponding to a noise component based on the phase-adjusted measurement signals;
• (vii) a subtracting unit configured to subtract the background signal from the phase-adjusted measurement signals;
• and
• (viii) an image generation unit configured to generate a tomographic image of the subject based on the phase-adjusted measurement signals from which the background signal is subtracted.

An image processing method comprising:

• acquiring measurement signals including information on a tomography of a subject in a depth direction obtained by performing optical coherence tomography on the subject;
• acquiring a base signal based on the measurement signals;
• calculating phase shifts between the measurement signals and the base signal;
• smoothing the phase shifts;
• adjusting phases of the measurement signals corresponding to the smoothed phase shifts based on the smoothed phase shifts;
• generating a background signal corresponding to a noise component based on the phase-adjusted measurement signals;
• subtracting the background signal from the phase-adjusted measurement signals;
• and
• generating a tomographic image of the subject based on the phase-adjusted measurement signals from which the background signal is subtracted.