Method of compensating illuminance variation due to skew and pitched field of view from a handheld scanner

An imaging-based data capture device comprising:

• an imaging assembly operable to capture image data over a field of view;
• an illumination assembly having a first illumination source and a second illumination source and operable to provide illumination light over at least a portion of the field of view;
• a processor communicatively coupled to the imaging assembly, the illumination assembly, and a memory;
• and
• the memory storing machine readable instruction that, when executed by the processor cause:
• the imaging assembly to capture a first frame with the illumination assembly providing illumination at a first level of intensity;
• the imaging assembly to capture a second frame with one of (i) the illumination assembly providing illumination at a second level of intensity that is lower than the first level of intensity or (ii) the illumination assembly in a deactivated state;
• determining, by the processor, a brightness difference between a plurality of respective regions of the first frame and the second frame;
• and
• capturing, by the image assembly, a third frame with the illumination assembly providing illumination at a third level of intensity that is different from the first level of intensity and the second level of intensity,
• wherein, the providing illumination, by the illumination assembly, at the third level of intensity includes driving a first illumination source of the illumination assembly with a first current and driving a second illumination source of the illumination assembly with a second current that is different from the first current, at least one of the first current or the second current being based on the brightness difference between the plurality of respective regions of the first frame and the second frame.