One or more spectrally encoded endoscopy (SEE) devices, systems, methods and storage mediums for characterizing, examining and/or diagnosing, and/or measuring viscosity of, a sample or object using speckle detection are provided. Examples of such applications include imaging, evaluating and diagnosing biological objects, such as, but not limited to, for Gastro-intestinal, cardio and/or ophthalmic applications, and being obtained via one or more optical instruments. Preferably, the SEE devices, systems methods and storage mediums include or involve speckle intensity autocorrelation function(s). One or more embodiments involve a serial time-encoded 2D imaging system with speckle detection to reconstruct images, store reconstructed images of the sample or object, and/or measure viscosity of the sample or object.