コード例 #1
0
ファイル: metadata.go プロジェクト: kitwalker12/fotomat
// MetadataImage returns Metadata from an Image. Format is always unset.
func MetadataImage(image *vips.Image) Metadata {
	o := DetectOrientation(image)
	w, h := o.Dimensions(image.Xsize(), image.Ysize())
	if w <= 0 || h <= 0 {
		panic("Invalid image dimensions.")
	}
	return Metadata{Width: w, Height: h, Orientation: o, HasAlpha: image.HasAlpha()}
}
コード例 #2
0
ファイル: save.go プロジェクト: kitwalker12/fotomat
func jpegSave(image *vips.Image, options SaveOptions) ([]byte, error) {
	// JPEG interlace saves 2-3%, but incurs a few hundred bytes of
	// overhead, requires buffering the image completely in RAM for
	// encoding and decoding, and takes over 3x the CPU.  This isn't
	// usually beneficial on small images and is too expensive for large
	// images.
	pixels := image.Xsize() * image.Ysize()
	interlace := pixels >= 200*200 && pixels <= 1024*1024

	// Strip and optimize both save space, enable them.
	return image.JpegsaveBuffer(true, options.Quality, true, interlace)
}
コード例 #3
0
ファイル: save.go プロジェクト: kitwalker12/fotomat
func useLossless(image *vips.Image, options SaveOptions) bool {
	if !options.Lossless {
		return false
	}

	if !options.LossyIfPhoto {
		return true
	}

	// Mobile devices start being unwilling to load >= 3 megapixel PNGs.
	// Also we don't want to bother to edge detect on large images.
	if image.Xsize()*image.Ysize() >= 3*1024*1024 {
		return false
	}

	// Take a histogram of a Sobel edge detect of our image.  What's the
	// highest number of histogram values in a row that are more than 1%
	// of the maximum value? Above 16 indicates a photo.
	metric, err := image.PhotoMetric(0.01)
	return err != nil || metric < 16
}