Using IrfanView (it’s freeware). You can download it here:
Open the image (File → Open).
Convert the image to grayscale (Image → Convert to Grayscale).
The above instructions were successfully tested with IrfanView 32bit (version 4.51).Subcribe now to LUNLUN.com newsletter and you will get the cheatsheet "Top 10 Trigonometry Formulas" as a gift.
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