An image-based hemoglobin estimation tool for measuring hemoglobin can be embedded in hand held devices such as smartphones, and similar known and to be developed technology. The hand-held device acquires video data of a finger illuminated from the dorsal surface by a first near infrared light responsive to hemoglobin and a second near infrared light near responsive to plasma. The acquired video is segmented into frames and processed to produce a Photoplethysmography (PPG) waveform. The features of the PPG waveform can then be identified, and the waveform and corresponding features evaluated by a predictive hemoglobin model. The predictive hemoglobin model can be provided at a remote computer, enabling non-invasive hemoglobin analysis from point of care locations. Near infrared lights of 850 nm and 1070 nm are particularly effective in the process.