The process for saving in NW4C_Tga (NW4C_ctex) format differs depending on whether an ETC filter has been applied.
This document describes this difference.
When an ETC filter has been applied
When an ETC filter has not been applied
When saving an image in ETC format NW4C_Tga (NW4R_ctex) and the image has not been modified since an ETC filter was applied, data in a state after application of the filter is output as additional information (double compression status does not result.).
| If an ETC filter has been applied and then data is saved, the Photoshop image quality cannot be changed back to the state before the filter was applied. When applying filtering, be careful not to save the resulting data in the same file used prior to filtering. |
If an image is modified after applying the ETC filter, that image will be handled in the same manner as if the filter was not applied.
When saving an image in ETC format NW4C_Tga (NW4C_ctex) and no ETC filter has been applied to the image, data for which images have been compressed at save time is output in additional information or in a ctex file.
When using NW4C_Tga, the image quality in Photoshop is always the same as prior to compression and the image quality will not be degraded when the data is saved.
CONFIDENTIAL