  We have created a map of the large-scale infrared surface brightness in
excess of that associated with the atomic interstellar medium, using
region-by-region correlations between the far-infrared and 21-cm line surface
brightness. Our study updates and extends a previous attempt with IRAS and
Berkeley/Parkes H I surveys. The far-infrared observations used here are from
DIRBE, which extends far-infrared wavelength coverage to 240 um, so that we are
reliably sampling the emission of large, thermal-equilibrium grains that
dominate the dust mass. The H I data are from the combined Leiden-Dwingeloo and
Parkes 21-cm line surveys. Using the maps of excess infrared emission at 100,
140, and 240 um, we created an atlas and identified the coherent structures.
These infrared excess clouds can be caused both by dust that is warmer than
average, or by dust associated with gas other than the atomic interstellar
medium. We find very few warm clouds, such as the H II region around Spica. The
majority of the infrared excess clouds are colder than the average atomic
interstellar medium. These clouds are peaks of column density, and their excess
infrared emission is due to dust associated with molecular gas. We identify
essentially all known high-latitude molecular clouds in the infrared excess
maps, and further identify a sample of new clouds with similar infrared
properties. The infrared excess was correlated with CO line brightness,
allowing us to measure the ratio of N(H2)/W(CO) for high-latitude clouds. The
atlas of infrared excess may be a useful guide to regions of relatively high
column density, which might cause high extinction toward extragalactic objects
at optical and ultraviolet wavelengths and confusion for cosmic infrared and
microwave backgrounds.
