Bolometer circuitry and methods for difference imaging

A bolometer circuit, comprising:

• an array of bolometers each configured to generate a pixel signal in response to a bias applied and incident infrared (IR) radiation received at the each bolometer, wherein the array of bolometers comprises:
• a plurality of amplifiers each having an input and an output,
• a first plurality of switches each configured to selectively provide a supply voltage to a respective bolometer of the array of bolometers,
• a second plurality of switches each configured to selectively connect a respective pair of bolometers in adjacent columns of the array,
• a third plurality of switches each configured to selectively route a difference of the pixel signals of a respective pair of bolometers in adjacent columns of the array to the input of a corresponding one of the plurality of amplifiers, and
• a fourth plurality of switches each configured to selectively provide a common voltage to a respective bolometer of the array of bolometers;
• and
• a control circuit configured to generate control signals for the first, second, third, and the fourth pluralities of switches to obtain, at the outputs of the amplifiers, column difference signals representative of the differences of the pixel signals for selected pairs of bolometers in adjacent columns of the array.

A method comprising:

• receiving an even difference image frame and an odd difference image frame, wherein the even difference image frame comprises even rows of difference data representative of infrared (IR) radiation intensity received at even rows of a bolometer array less IR radiation intensity received at respective adjacent odd rows of the bolometer array, and wherein the odd difference image frame comprises odd rows of difference data representative of IR radiation intensity received at odd rows of a bolometer array less IR radiation intensity received at respective adjacent even rows of the bolometer array;
• combining the even and the odd difference image frames to generate a composite difference image comprising both the even and the odd rows of difference data;
• and
• generating a direct image from the composite difference image by cumulatively adding the difference rows from top to bottom or bottom to top to generate rows of the direct image.