change codes to use png instead of jpg (#483)

* this will improve quality of qr-code, matrix-code and barcode.

docs/assets/text/barcodegridv2.txt

@@ -1,3 +1,3 @@
-generate -> avg: 1.37ms, executions: [1.37ms]
-add_row -> avg: 358.60ns, executions: [1.16μs, 0.17μs, 0.15μs, 0.10μs, 0.22μs]
-file_size -> 16.54Kb
+generate -> avg: 8.66ms, executions: [8.66ms]
+add_row -> avg: 329.00ns, executions: [1.21μs, 0.14μs, 0.12μs, 0.07μs, 0.09μs]
+file_size -> 6.85Kb

docs/assets/text/datamatrixgridv2.txt

@@ -1,3 +1,3 @@
-generate -> avg: 177.74μs, executions: [177.74μs]
-add_row -> avg: 315.50ns, executions: [876.00ns, 162.00ns, 134.00ns, 90.00ns]
-file_size -> 5.27Kb
+generate -> avg: 208.63μs, executions: [208.63μs]
+add_row -> avg: 270.75ns, executions: [747.00ns, 152.00ns, 100.00ns, 84.00ns]
+file_size -> 5.14Kb

docs/assets/text/qrgridv2.txt

@@ -1,3 +1,3 @@
-generate -> avg: 199.99μs, executions: [199.99μs]
-add_row -> avg: 426.00ns, executions: [1.25μs, 0.21μs, 0.14μs, 0.10μs]
-file_size -> 5.34Kb
+generate -> avg: 180.99μs, executions: [180.99μs]
+add_row -> avg: 292.00ns, executions: [864.00ns, 131.00ns, 100.00ns, 73.00ns]
+file_size -> 5.18Kb

internal/code/code.go

@@ -3,7 +3,9 @@ package code
 import (
 	"bytes"
 	"image"
-	"image/jpeg"
+	"image/color/palette"
+	"image/draw"
+	"image/png"
 
 	"github.com/boombuler/barcode/code128"
 	"github.com/boombuler/barcode/ean"
@@ -85,17 +87,22 @@ func getBarcodeClosure(barcodeType barcode.Type) func(code string) (libBarcode.B
 
 func (c *code) getImage(img image.Image) (*entity.Image, error) {
 	var buf bytes.Buffer
-	err := jpeg.Encode(&buf, img, nil)
+
+	dst := image.NewPaletted(img.Bounds(), palette.Plan9)
+	drawer := draw.Drawer(draw.Src)
+	drawer.Draw(dst, dst.Bounds(), img, img.Bounds().Min)
+
+	err := png.Encode(&buf, dst)
 	if err != nil {
 		return nil, err
 	}
 
 	imgEntity := &entity.Image{
 		Bytes:     buf.Bytes(),
-		Extension: extension.Jpg,
+		Extension: extension.Png,
 		Dimensions: &entity.Dimensions{
-			Width:  float64(img.Bounds().Dx()),
-			Height: float64(img.Bounds().Dy()),
+			Width:  float64(dst.Bounds().Dx()),
+			Height: float64(dst.Bounds().Dy()),
 		},
 	}
 

internal/providers/gofpdf/provider.go

@@ -69,7 +69,7 @@ func (g *provider) AddMatrixCode(code string, cell *entity.Cell, prop *props.Rec
 		return
 	}
 
-	err = g.image.Add(img, cell, g.cfg.Margins, prop, extension.Jpg, false)
+	err = g.image.Add(img, cell, g.cfg.Margins, prop, extension.Png, false)
 	if err != nil {
 		g.fpdf.ClearError()
 		g.text.Add("could not add matrixcode to document", cell, merror.DefaultErrorText)
@@ -83,15 +83,15 @@ func (g *provider) AddQrCode(code string, cell *entity.Cell, prop *props.Rect) {
 		return
 	}
 
-	err = g.image.Add(img, cell, g.cfg.Margins, prop, extension.Jpg, false)
+	err = g.image.Add(img, cell, g.cfg.Margins, prop, extension.Png, false)
 	if err != nil {
 		g.fpdf.ClearError()
 		g.text.Add("could not add qrcode to document", cell, merror.DefaultErrorText)
 	}
 }
 
 func (g *provider) AddBarCode(code string, cell *entity.Cell, prop *props.Barcode) {
-	image, err := g.cache.GetImage(g.getBarcodeImageName(fmt.Sprintf("bar-code-%s", code), prop), extension.Jpg)
+	image, err := g.cache.GetImage(g.getBarcodeImageName(fmt.Sprintf("bar-code-%s", code), prop), extension.Png)
 	if err != nil {
 		image, err = g.code.GenBar(code, cell, prop)
 	}
@@ -101,7 +101,7 @@ func (g *provider) AddBarCode(code string, cell *entity.Cell, prop *props.Barcod
 	}
 
 	g.cache.AddImage(g.getBarcodeImageName(fmt.Sprintf("bar-code-%s", code), prop), image)
-	err = g.image.Add(image, cell, g.cfg.Margins, prop.ToRectProp(), extension.Jpg, false)
+	err = g.image.Add(image, cell, g.cfg.Margins, prop.ToRectProp(), extension.Png, false)
 	if err != nil {
 		g.fpdf.ClearError()
 		g.text.Add("could not add barcode to document", cell, merror.DefaultErrorText)
@@ -230,7 +230,7 @@ func (g *provider) GetDimensionsByMatrixCode(code string) (*entity.Dimensions, e
 		return nil, err
 	}
 
-	imgInfo, _ := g.image.GetImageInfo(img, extension.Jpg)
+	imgInfo, _ := g.image.GetImageInfo(img, extension.Png)
 
 	if imgInfo == nil {
 		return nil, errors.New("could not read image options, maybe path/name is wrong")
@@ -246,7 +246,7 @@ func (g *provider) GetDimensionsByQrCode(code string) (*entity.Dimensions, error
 		return nil, err
 	}
 
-	imgInfo, _ := g.image.GetImageInfo(img, extension.Jpg)
+	imgInfo, _ := g.image.GetImageInfo(img, extension.Png)
 	if imgInfo == nil {
 		return nil, errors.New("could not read image options, maybe path/name is wrong")
 	}
@@ -278,7 +278,7 @@ func (g *provider) getBarcodeImageName(code string, prop *props.Barcode) string
 
 // loadImage is responsible for loading an codes
 func (g *provider) loadCode(code, codeType string, generate func(code string) (*entity.Image, error)) (*entity.Image, error) {
-	image, err := g.cache.GetImage(codeType+code, extension.Jpg)
+	image, err := g.cache.GetImage(codeType+code, extension.Png)
 	if err != nil {
 		image, err = generate(code)
 	} else {