WriteImage – Multispectral Image in ENVI

Having created a multispectral image using ”ReadStack”, you may want to store it on the disk. One easy file format to use for multispectral images is the Envi format.

An Envi file consists of two files, a header file and a data file. They both have the same name, except that the header file ends with “.hdr”, while the data file has no extension. Hoku looks for the “.hdr” extension to find Envi files. Although created with ReadStack, a multispectral Envi file can be most easily read in, at a later time, using ReadImage.

In “WriteImage”, select the “Envi” format button and be sure to end the file name with a “.hdr” extension. The “interleave” method that you choose will depend on the purpose of the file. If you intend to use it as an input image, then use BIP, because that is the format in which the processing routines will work. If you are storing multispectral processed data, where you have many output bands, such as with PCA, then use the BSQ interleave so that you can more easily inspect each band individually.

If you specify a “window” then only the data from that rectangular region will be read from the disk.