image file convert to 0.98 inch OLED

Resize by Gimp

Tools > Transform  tools > Scale 

then 128 x 64

Change to 2 bit

Image > mode > indexed 

select 1bit

Export as c source header

covert to binary to hex with 0x at https://www.rapidtables.com/convert/number/ascii-hex-bin-dec-converter.html