  Upconversion imaging, where mid infrared (IR) photons are converted to
visible and near IR photons via a nonlinear crystal and detected on cheap and
high-performance Silicon detectors, is an appealing method to address the
limitations of thermal sensors which are expensive, often require cooling and
suffer from both limited spectral response and limited spatial resolution as
well as poor sensitivity. However, phase matching severely limits the spectral
bandwidth of this technique therefore requiring serial acquisitions in order to
cover a large spectrum. Here, we introduce a novel upconversion imaging scheme
covering the mid IR based on adiabatic frequency conversion. We present a mid
IR multicolor imaging and demonstrate simultaneous imaging on a CMOS camera of
radiation spanning a spectrum from 2 to 4 \mu m. Our approach being coherent
and ultrafast in essence, we further demonstrate spectrally resolved
spatio-temporal imaging which allows spatially distinguishing the temporal
evolution of spectral components.
