Reputation: 3265
I am loading a jpeg from the disk, and I would like to do some RGBA operations on it.
However, since the jpeg is not RGBA, i get an error when I try to use it as such:
thumbnail,err:=jpeg.Decode(imageAsReader)
...
return thumbnail.(*image.RGBA)
yeileds the error:
interface conversion: image.Image is *image.YCbCr, not *image.RGBA
Is there an easy way to convert the image to RGBA once I have loaded it in memory? (Other operations are in RGBA later on, so that is the color model I want to use in memory).
Upvotes: 2
Views: 4188
Reputation: 5720
As the comments suggest, you have to create a new image and draw into it:
b := thumbnail.Bounds()
m := image.NewRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))
draw.Draw(m, m.Bounds(), thumbnail, b.Min, draw.Src)
YCbCr is a sub-sampled image, so it doesn't map directly to the 4-bytes-per-pixel of RGBA.
Upvotes: 4