imageutil

func AddBackgroundWhite ¶

func AddBackgroundWhite(imgSrc image.Image) image.Image

AddBackgroundWhite adds a white background which is usable when the image has a transparent background.

func Aspect ¶

func Aspect(width, height int) float64

func BestScaler ¶

func BestScaler() draw.Scaler

func DefaultScaler ¶

func DefaultScaler() draw.Scaler

DefaultScaler returns a general best results interpolation algorithm. See more here https://blog.codinghorror.com/better-image-resizing/ , https://support.esri.com/en/technical-article/000005606 , https://stackoverflow.com/questions/384991/what-is-the-best-image-downscaling-algorithm-quality-wise/6171860 .

func ImageAspect ¶

func ImageAspect(img image.Image) float64

func ImageWidthHeight ¶

func ImageWidthHeight(img image.Image) (int, int)

func IsImageExt ¶

func IsImageExt(imagePath string) bool

func MergeHorizontalRGBA ¶

func MergeHorizontalRGBA(ims ImageMetaSet) image.Image

MergeHorizontalRGBA returns an image that is composed of non-overlapping imagers in ImageMetaSet. The code here is adapted from https://stackoverflow.com/a/35965499/1908967

func OverlayCenterYLeftAlign ¶

func OverlayCenterYLeftAlign(imgBg, imgOver image.Image) image.Image

func ParseScalar ¶

func ParseScalar(rawInterpolation string) (draw.Scaler, error)

func ReadImage ¶

func ReadImage(filename string) (image.Image, error)

func ReadImageDimensions ¶

func ReadImageDimensions(imagePath string) (int, int, error)

func Resize ¶

func Resize(width, height uint, src image.Image, scale draw.Scaler) image.Image

Resize scales an image to the provided size units. Use a 0 to scale the aspect ratio. See gitub.com/nfnt/resize for Lanczos3, etc. https://github.com/nfnt/resize .

func Scale ¶

func Scale(src image.Image, rect image.Rectangle, scale draw.Scaler) image.Image

Scale will resize the image to the provided rectangle using the provided interpolation function.

func WriteFileJPEG ¶

func WriteFileJPEG(filename string, img image.Image, quality int) error

func WriteFilePNG ¶

func WriteFilePNG(filename string, img image.Image) error