The work now i am doing is transplanting a project from iOS to Android. The problem is the resource is too big, both the file size and memory usage.
After do search in the internet and consult some friends, i am focusing on the ect1 format of compressed texture. Since it is the basic format of texture compression of OpenGL ES 2.0,
almost all the android machines support it.
The tool i have used is Mali Texture Compression Tool v4.0.1. Just at the begining, some problem happend:
the transformed ".ktx" file size is too bigger against the imagination.
The original image format is png-24.
I found some ktx file sizes are about the half of png, and some unexpectedly are bigger than png files. And i also did the compression of the whole resource, and the total size is also bigger than png format. What a puzzled!
To my opinion, if the etc1 represent a pixel with 4 bits(0.5 byte), the transformed ".ktx" file size should be more or less with png-8(4 bits depth).
The order i used is:
etcpack.exe input_filename out_directory -s fast -e perceptual -c etc1 -ktx
Is there some wrong with the arguments?
Or my imagination of the compression ratio is not right?