package images import ( "bytes" "fmt" "image" "image/color" "image/draw" "image/png" "math" "os" "github.com/nfnt/resize" "github.com/oliamb/cutter" "go.uber.org/zap" xdraw "golang.org/x/image/draw" "github.com/ethereum/go-ethereum/log" ) type Circle struct { X, Y, R int } func (c *Circle) ColorModel() color.Model { return color.AlphaModel } func (c *Circle) Bounds() image.Rectangle { return image.Rect(c.X-c.R, c.Y-c.R, c.X+c.R, c.Y+c.R) } func (c *Circle) At(x, y int) color.Color { xx, yy, rr := float64(x-c.X)+0.5, float64(y-c.Y)+0.5, float64(c.R) if xx*xx+yy*yy < rr*rr { return color.Alpha{255} } return color.Alpha{0} } func Resize(size ResizeDimension, img image.Image) image.Image { var width, height uint switch { case img.Bounds().Max.X == img.Bounds().Max.Y: width, height = uint(size), uint(size) case img.Bounds().Max.X > img.Bounds().Max.Y: width, height = 0, uint(size) default: width, height = uint(size), 0 } log.Info("resizing", "size", size, "width", width, "height", height) return resize.Resize(width, height, img, resize.Bilinear) } func ResizeTo(percent int, img image.Image) image.Image { width := uint(img.Bounds().Max.X * percent / 100) height := uint(img.Bounds().Max.Y * percent / 100) return resize.Resize(width, height, img, resize.Bilinear) } func ShrinkOnly(size ResizeDimension, img image.Image) image.Image { finalSize := int(math.Min(float64(size), math.Min(float64(img.Bounds().Dx()), float64(img.Bounds().Dy())))) return Resize(ResizeDimension(finalSize), img) } func Crop(img image.Image, rect image.Rectangle) (image.Image, error) { if img.Bounds().Max.X < rect.Max.X || img.Bounds().Max.Y < rect.Max.Y { return nil, fmt.Errorf( "crop dimensions out of bounds of image, image width '%dpx' & height '%dpx'; crop bottom right coordinate at X '%dpx' Y '%dpx'", img.Bounds().Max.X, img.Bounds().Max.Y, rect.Max.X, rect.Max.Y, ) } return cutter.Crop(img, cutter.Config{ Width: rect.Dx(), Height: rect.Dy(), Anchor: rect.Min, }) } // CropCenter takes an image, usually downloaded from a URL // If the image is square, the full image is returned // If the image is rectangular, the largest central square is returned // calculations at _docs/image-center-crop-calculations.png func CropCenter(img image.Image) (image.Image, error) { var cropRect image.Rectangle maxBounds := img.Bounds().Max if maxBounds.X == maxBounds.Y { return img, nil } if maxBounds.X > maxBounds.Y { // the final output should be YxY cropRect = image.Rectangle{ Min: image.Point{X: maxBounds.X/2 - maxBounds.Y/2, Y: 0}, Max: image.Point{X: maxBounds.X/2 + maxBounds.Y/2, Y: maxBounds.Y}, } } else { // the final output should be XxX cropRect = image.Rectangle{ Min: image.Point{X: 0, Y: maxBounds.Y/2 - maxBounds.X/2}, Max: image.Point{X: maxBounds.X, Y: maxBounds.Y/2 + maxBounds.X/2}, } } return Crop(img, cropRect) } func ImageToBytes(imagePath string) ([]byte, error) { // Open the image file file, err := os.Open(imagePath) if err != nil { return nil, err } defer file.Close() // Decode the image img, _, err := image.Decode(file) if err != nil { return nil, err } // Create a new buffer to hold the image data var imgBuffer bytes.Buffer // Encode the image to the desired format and save it in the buffer err = png.Encode(&imgBuffer, img) if err != nil { return nil, err } // Return the image data as a byte slice return imgBuffer.Bytes(), nil } func AddPadding(img image.Image, padding int) *image.RGBA { bounds := img.Bounds() newBounds := image.Rect(bounds.Min.X-padding, bounds.Min.Y-padding, bounds.Max.X+padding, bounds.Max.Y+padding) paddedImg := image.NewRGBA(newBounds) draw.Draw(paddedImg, newBounds, &image.Uniform{C: color.White}, image.ZP, draw.Src) return paddedImg } func EncodePNG(img *image.RGBA) ([]byte, error) { resultImg := &bytes.Buffer{} err := png.Encode(resultImg, img) if err != nil { return nil, err } return resultImg.Bytes(), nil } func CreateCircleWithPadding(img image.Image, padding int) *image.RGBA { bounds := img.Bounds() width := bounds.Dx() // only relying on width as a metric here because we know that we // store profile images in a perfect circle radius := width / 2 paddedWidth := width + 2*padding paddedRadius := paddedWidth / 2 // Create a new circular image with padding newBounds := image.Rect(0, 0, paddedWidth, paddedWidth) circle := image.NewRGBA(newBounds) // Create a larger circular mask for the padding paddingMask := &Circle{ X: paddedRadius, Y: paddedRadius, R: paddedRadius, } // Draw the white color onto the circle with padding mask draw.DrawMask(circle, circle.Bounds(), image.NewUniform(color.White), image.ZP, paddingMask, image.ZP, draw.Src) // Create a new circle mask with the original size circleMask := &Circle{ X: radius, Y: radius, R: radius, } // Draw the original image onto the white circular image at the center (with padding offset) draw.DrawMask(circle, bounds.Add(image.Pt(padding, padding)), img, image.ZP, circleMask, image.ZP, draw.Over) return circle } func PlaceCircleInCenter(paddedImg, circle *image.RGBA) *image.RGBA { bounds := circle.Bounds() centerX := (paddedImg.Bounds().Min.X + paddedImg.Bounds().Max.X) / 2 centerY := (paddedImg.Bounds().Min.Y + paddedImg.Bounds().Max.Y) / 2 draw.Draw(paddedImg, bounds.Add(image.Pt(centerX-bounds.Dx()/2, centerY-bounds.Dy()/2)), circle, image.ZP, draw.Over) return paddedImg } func ResizeImage(imgBytes []byte, width, height int) ([]byte, error) { // Decode image bytes img, _, err := image.Decode(bytes.NewReader(imgBytes)) if err != nil { return nil, err } // Create a new image with the desired dimensions newImg := image.NewNRGBA(image.Rect(0, 0, width, height)) xdraw.BiLinear.Scale(newImg, newImg.Bounds(), img, img.Bounds(), draw.Over, nil) // Encode the new image to bytes var newImgBytes bytes.Buffer if err = png.Encode(&newImgBytes, newImg); err != nil { return nil, err } return newImgBytes.Bytes(), nil } func SuperimposeLogoOnQRImage(imageBytes []byte, qrFilepath []byte) []byte { // Read the two images from bytes img1, _, err := image.Decode(bytes.NewReader(imageBytes)) if err != nil { log.Error("error decoding logo Image", zap.Error(err)) return nil } img2, _, err := image.Decode(bytes.NewReader(qrFilepath)) if err != nil { log.Error("error decoding QR Image", zap.Error(err)) return nil } // Create a new image with the dimensions of the first image result := image.NewRGBA(img1.Bounds()) // Draw the first image on the new image draw.Draw(result, img1.Bounds(), img1, image.ZP, draw.Src) // Get the dimensions of the second image img2Bounds := img2.Bounds() // Calculate the x and y coordinates to center the second image x := (img1.Bounds().Dx() - img2Bounds.Dx()) / 2 y := (img1.Bounds().Dy() - img2Bounds.Dy()) / 2 // Draw the second image on top of the first image at the calculated coordinates draw.Draw(result, img2Bounds.Add(image.Pt(x, y)), img2, image.ZP, draw.Over) // Encode the final image to a desired format var b bytes.Buffer err = png.Encode(&b, result) if err != nil { log.Error("error encoding final result Image to Buffer", zap.Error(err)) return nil } return b.Bytes() }