Prism

Fast Go image encoding, decoding, and transformations using OpenCV, libpng, and libjpeg-turbo.

Dependencies (dynamically linked)

• opencv 2.4.x
• libturbo-jpeg 1.4+

Example

import(
"os""github.com/cotap/prism"
)
funcmain() {
f, _:=os.Open("example.jpg")
img, _:=prism.Decode(f)
deferimg.Release() // ensures timely release of C heap memory_=img.FlipV()
_=img.Fit(500, 500)
w, _:=os.Create("resized.jpg")
deferw.Close()
// fast encoding with libjpeg-turboprism.EncodeJPEG(w, img, 90)
// or, since prism.Image implements image.Image:// jpeg.Encode(w, img, &jpeg.Options{Quality: 90})
}

Memory Management

Prism allocates memory for image decoding and processing using the OpenCV allocator on the C heap. In order to avoid long-term leaks, prism uses Go's runtime.SetFinalizer to release C memory when the Go object is GC'd.

HOWEVER, because Go's collector can't see into the C heap, it may not run as frequently as needed to keep memory usage low. In order to ensure most efficient memory usage, always call func (img *prism.Image) Release() after you're done with an image.