The following guidelines based on IrfanView (http://www.irfanview.com/) software:
8. Select “Use advanced Options.”
Set the height of the GIF to 96 pixels.
Select preserve aspect ratio
9. Select “Use Options.”
Select “keep original data boxes”
10. Press Start Batch
Using IrfanView software, follow the same process used to create GIFs, except:
Select “Advanced Options.” Under “Set New Size” set the long side to 1024 pixels.
Press Start Batch