float > byte? | GameDev.net

Original Post

Jan 5, 2003 at 3:22 AM

i''m using floats to work with RGB data, and i''d like to find out a way to convert them into bytes. the image data has a max of 1.0f and a minimum of -1.0f anybody have the formula to convert this value into an unsigned char? thanks in advance

Dean Harding

Jan 5, 2003 at 3:33 AM

unsigned char byte = (unsigned char)((f + 1.0f) * 127.5f);

You add one to make it go from 0 to 2, then multiply it by 127.5 to make it go from 0 to 255.

I recommend you don''t store your images like this, though. All the conversion between floats and integers will have a pretty big impact on performance. Image a 128x128 image, that''s 128x128x3 float->integer conversions, for a total of just under 50,000. That''s quite a bit for a relatively small image - image a 1024x1024 image...

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Landsknecht

Jan 5, 2003 at 4:54 AM

Not to mention the massive precision loss every time you compute the values...

God was my co-pilot but we crashed in the mountains and I had to eat him...

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