Secondary data set information is incorporated into a primary data set (such as a digital image) retaining a desired dynamic range and retaining the original primary set data quality. The secondary data set information is `smuggled` into the least significant bits of the primary data set to result in an enhanced data set. If desired, the primary data word can be shifted toward the most significant bit. The enhanced data set may be viewed as if it were the original primary data set with existing playback devices, however it now includes additional `smuggled` information which may be played back in coordination with the primary data set information. One example is flow-direction information `smuggled` into an angiographic image. The least significant bits of the enhanced data words may be used to select the color map and color code the images. A user-adjustable intensity threshold can also be employed to select between color maps. Information stored in this fashion results in a substantial savings in disk storage requirements. Also, since the information of the primary and secondary data sets are merged into a single word, they will remain together throughout many different types of processing, such as maximum intensity projection in volumetric imaging.