CODEWITHSUNDEEP
iphoneimagerotationuiimagegpu
user938797
user938797

Reputation: 177

Fast rotation of an image (bitmap) on an iPhone for an arbitrary degree

I need to rotate a full size photo (about 8MB) as fast as possible on an iPhone (4s and up), an arbitrary angle. The code to do so with CoreImage is easy enough, but not fast. It takes about 1.5 seconds on a 4s. Please note that the purpose of this rotate is for further image processing in memory, NOT for display on the screen.

Is there any kind of hope that we can get this down to sub-second given, perhaps, the DSP (using the Accelerate framework) or OpenGL (and keeping in mind that we have to copy the bits in and out of whatever buffer we using. If this is hopeless then we have other (but more complicated) ways to tackle the job. I have not written OpenGL code before and want some assurance that this will actually work before I spend significant time on it!

Thank you, Ken

Upvotes: 0

Views: 180

Answers (1)

DubiousPusher
DubiousPusher

Reputation: 1182

Since you have it running at 1.5s with no hardware acceleration I'd say it's safe to assume you can get it under a second with OpenGL.

Upvotes: 1

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