Sharky Extreme has received quite a bit of feedback on our 3dfx FXT1 Compression Explored article and several of you commented on the quality and accuracy of the 3dfx supplied compression comparison images on page one. We would like to say that we found the time to do a bit of experimenting on our own and came up with these brilliant images ourselves but that would be a whopping fib. Instead, we were fortunate enough to have a graphic artist, Scott Cohen, volunteer these images and step by step instructions for how he compared compression methods. Here is a composite he made from images using the method described below.
Click for full image - 475kb
This method assumes that you have installed and have a working knowledge of an image editing program (such as Photoshop or Paint) and the texture compression tools put out by both S3 and 3Dfx. Get Scott's original images here (~500Kb). If you do not have the texture compression tools, you can get the 3dfx FXT1 tools here and the S3TC tools here
PROCESS 1
- Open the file comparexmple1.bmp with the S3 compression tool or Photoshop with the S3 plug-in installed.
- Compress the file.
- Save as S3T or DDS file.
- Open the file comparexmple1.bmp with the 3dfx compression tool or Photoshop with the 3dfx plug-in installed.
- Compress the file.
- Save as FXT file.
PROCESS 2
- Open the compressed file comparexmple1.s3t or comparexmple1.dds in the paint program.
- Crop an area with detail 480 pixels wide and 320 high.
- Select "Nearest Neighbor" as the interpolation method and scale the image 400% or to 1024 by 1280.
- This allows you to see enlarged detail of the compression artifacts.
- Save the image if you like in a non-lossy format such as BMP or TGA.
- Repeat this process 2 using the comparexmple1.fxt file
- You now have 2 images with detail blowups comparing both compression methods.
PROCESS 3
- Open the file comparexmple2.bmp with the S3 compression tool or Photoshop with the S3 plug-in installed.
- Compress the file.
- Save as S3T or DDS file.
- Open the file comparexmple2.bmp with the 3dfx compression tool or Photoshop with the 3dfx plug-in installed.
- Compress the file.
- Save as FXT file.
PROCESS 4
- Open the compressed file comparexmple2.s3t or comparexmple2.dds in the paint program.
- Save the image if you like in a non-lossy format such as BMP or TGA.
- Repeat process 4 using the comparexmple2.fxt file
- You now have 2 images with high color ranges comparing both compression methods.