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Add NewGrayImageFromGoImage method

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This commit is contained in:
Adrian-George Bostan 2019-01-24 22:23:54 +02:00
parent fc21d4820d
commit c9d9b7dee7
1 changed files with 26 additions and 2 deletions
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28
pdf/model/image.go
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@ -223,9 +223,12 @@ type ImageHandler interface {
// Read any image type and load into a new Image object.
Read(r io.Reader) (*Image, error)
// NewImageFromGoImage load a unidoc Image from a standard Go image structure.
// NewImageFromGoImage loads a RGB unidoc Image from a standard Go image structure.
NewImageFromGoImage(goimg goimage.Image) (*Image, error)
// NewGrayImageFromGoImage loads a grayscale unidoc Image from a standard Go image structure.
NewGrayImageFromGoImage(goimg goimage.Image) (*Image, error)
// Compress an image.
Compress(input *Image, quality int64) (*Image, error)
}
@ -233,7 +236,7 @@ type ImageHandler interface {
// DefaultImageHandler is the default implementation of the ImageHandler using the standard go library.
type DefaultImageHandler struct{}
// NewImageFromGoImage creates a unidoc Image from a golang Image.
// NewImageFromGoImage creates a new RGB unidoc Image from a golang Image.
func (ih DefaultImageHandler) NewImageFromGoImage(goimg goimage.Image) (*Image, error) {
// Speed up jpeg encoding by converting to RGBA first.
// Will not be required once the golang image/jpeg package is optimized.
@ -271,6 +274,27 @@ func (ih DefaultImageHandler) NewImageFromGoImage(goimg goimage.Image) (*Image,
return &imag, nil
}
// NewGrayImageFromGoImage creates a new grayscale unidoc Image from a golang Image.
func (ih DefaultImageHandler) NewGrayImageFromGoImage(goimg goimage.Image) (*Image, error) {
b := goimg.Bounds()
m := goimage.NewGray(goimage.Rect(0, 0, b.Dx(), b.Dy()))
draw.Draw(m, m.Bounds(), goimg, b.Min, draw.Src)
data := []byte{}
for i := 0; i < len(m.Pix); i += 1 {
data = append(data, m.Pix[i])
}
imag := Image{}
imag.Width = int64(b.Dx())
imag.Height = int64(b.Dy())
imag.BitsPerComponent = 8
imag.ColorComponents = 1
imag.Data = data // buf.Bytes()
return &imag, nil
}
// Read reads an image and loads into a new Image object with an RGB
// colormap and 8 bits per component.
func (ih DefaultImageHandler) Read(reader io.Reader) (*Image, error) {