How create UIImage from bytes?

Question

I need in UIImage created from my colors (for example, i need in image 1x1 pixel with black color).

I've got array:

unsigned char *color[] = {0, 0, 0, 1};

How can i create UIImage from this array ?

I've try

 unsigned char *bytes[4] = {0,0,0,1};
 NSData *data = [NSData dataWithBytes:bytes length:4];
 UIImage *img = [UIImage imageWithData:data];

but this method has no result...

Ben Gottlieb · Accepted Answer · 2010-04-11 16:06:01Z

3

You'll want to create a bitmap context (using CGBitmapContextCreate()), and draw into that. This requires using CoreGraphics. Then take your context and use CGBitmapContextCreateImage() to create an CGImageRef out of it. Finally, use +[UIImage imageWithCGImage:] to convert that CGImageRef to a UIImage.

answered Apr 11, 2010 at 16:06

Ben Gottlieb

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1 Comment

Sergey Kopanev Over a year ago

Thanks, i'm trying this, but i have problem with alpha channel. I've got picture with ALPHA channel, and i try change color (for example: from yellow to green) and i think alpha must keep... I've try this: milytia.org/paste/117 when brush is RGBA bytes array. When i run it i have artefacts on my generated image (on ALPHA place)...

Sergey Kopanev · Accepted Answer · 2010-04-13 21:27:26Z

1

Thank you, all!

This is solved my problem.

http://www.iphonedevsdk.com/forum/iphone-sdk-development/23525-cgimagecreate-alpha.html

answered Apr 13, 2010 at 21:27

Sergey Kopanev

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