diff options
Diffstat (limited to 'vendor/github.com/disintegration/imaging/README.md')
| -rw-r--r-- | vendor/github.com/disintegration/imaging/README.md | 191 |
1 files changed, 92 insertions, 99 deletions
diff --git a/vendor/github.com/disintegration/imaging/README.md b/vendor/github.com/disintegration/imaging/README.md index 3dcea2000..f957c3e79 100644 --- a/vendor/github.com/disintegration/imaging/README.md +++ b/vendor/github.com/disintegration/imaging/README.md @@ -26,17 +26,18 @@ http://godoc.org/github.com/disintegration/imaging A few usage examples can be found below. See the documentation for the full list of supported functions.
### Image resizing
+
```go
-// resize srcImage to size = 128x128px using the Lanczos filter
+// Resize srcImage to size = 128x128px using the Lanczos filter.
dstImage128 := imaging.Resize(srcImage, 128, 128, imaging.Lanczos)
-// resize srcImage to width = 800px preserving the aspect ratio
+// Resize srcImage to width = 800px preserving the aspect ratio.
dstImage800 := imaging.Resize(srcImage, 800, 0, imaging.Lanczos)
-// scale down srcImage to fit the 800x600px bounding box
+// Scale down srcImage to fit the 800x600px bounding box.
dstImageFit := imaging.Fit(srcImage, 800, 600, imaging.Lanczos)
-// resize and crop the srcImage to fill the 100x100px area
+// Resize and crop the srcImage to fill the 100x100px area.
dstImageFill := imaging.Fill(srcImage, 100, 100, imaging.Center, imaging.Lanczos)
```
@@ -53,146 +54,138 @@ The full list of supported filters: NearestNeighbor, Box, Linear, Hermite, Mitc **Resampling filters comparison**
-Original image. Will be resized from 512x512px to 128x128px.
-
-
-
-Filter | Resize result
----|---
-`imaging.NearestNeighbor` | 
-`imaging.Box` | 
-`imaging.Linear` | 
-`imaging.MitchellNetravali` | 
-`imaging.CatmullRom` | 
-`imaging.Gaussian` | 
-`imaging.Lanczos` | 
-
-**Resize functions comparison**
+The original image.
-Original image:
+
-
-
-Resize the image to width=100px and height=100px:
-
-```go
-dstImage := imaging.Resize(srcImage, 100, 100, imaging.Lanczos)
-```
-
+The same image resized from 512x512px to 128x128px using different resampling filters.
+From faster (lower quality) to slower (higher quality):
-Resize the image to width=100px preserving the aspect ratio:
-
-```go
-dstImage := imaging.Resize(srcImage, 100, 0, imaging.Lanczos)
-```
-
-
-Resize the image to fit the 100x100px boundng box preserving the aspect ratio:
-
-```go
-dstImage := imaging.Fit(srcImage, 100, 100, imaging.Lanczos)
-```
-
+Filter | Resize result
+--------------------------|---------------------------------------------
+`imaging.NearestNeighbor` | 
+`imaging.Linear` | 
+`imaging.CatmullRom` | 
+`imaging.Lanczos` | 
-Resize and crop the image with a center anchor point to fill the 100x100px area:
-
-```go
-dstImage := imaging.Fill(srcImage, 100, 100, imaging.Center, imaging.Lanczos)
-```
-
### Gaussian Blur
+
```go
dstImage := imaging.Blur(srcImage, 0.5)
```
Sigma parameter allows to control the strength of the blurring effect.
-Original image | Sigma = 0.5 | Sigma = 1.5
----|---|---
- |  | 
+Original image | Sigma = 0.5 | Sigma = 1.5
+-----------------------------------|----------------------------------------|---------------------------------------
+ |  | 
### Sharpening
+
```go
dstImage := imaging.Sharpen(srcImage, 0.5)
```
-Uses gaussian function internally. Sigma parameter allows to control the strength of the sharpening effect.
+`Sharpen` uses gaussian function internally. Sigma parameter allows to control the strength of the sharpening effect.
-Original image | Sigma = 0.5 | Sigma = 1.5
----|---|---
- |  | 
+Original image | Sigma = 0.5 | Sigma = 1.5
+-----------------------------------|-------------------------------------------|------------------------------------------
+ |  | 
### Gamma correction
+
```go
dstImage := imaging.AdjustGamma(srcImage, 0.75)
```
-Original image | Gamma = 0.75 | Gamma = 1.25
----|---|---
- |  | 
+Original image | Gamma = 0.75 | Gamma = 1.25
+-----------------------------------|------------------------------------------|-----------------------------------------
+ |  | 
### Contrast adjustment
+
```go
dstImage := imaging.AdjustContrast(srcImage, 20)
```
-Original image | Contrast = 20 | Contrast = -20
----|---|---
- |  | 
+Original image | Contrast = 10 | Contrast = -10
+-----------------------------------|--------------------------------------------|-------------------------------------------
+ |  | 
### Brightness adjustment
+
```go
dstImage := imaging.AdjustBrightness(srcImage, 20)
```
-Original image | Brightness = 20 | Brightness = -20
----|---|---
- |  | 
-
+Original image | Brightness = 10 | Brightness = -10
+-----------------------------------|----------------------------------------------|---------------------------------------------
+ |  | 
-### Complete code example
-Here is the code example that loads several images, makes thumbnails of them
-and combines them together side-by-side.
+## Example code
```go
package main
import (
- "image"
- "image/color"
-
- "github.com/disintegration/imaging"
+ "image"
+ "image/color"
+ "log"
+
+ "github.com/disintegration/imaging"
)
func main() {
-
- // input files
- files := []string{"01.jpg", "02.jpg", "03.jpg"}
-
- // load images and make 100x100 thumbnails of them
- var thumbnails []image.Image
- for _, file := range files {
- img, err := imaging.Open(file)
- if err != nil {
- panic(err)
- }
- thumb := imaging.Thumbnail(img, 100, 100, imaging.CatmullRom)
- thumbnails = append(thumbnails, thumb)
- }
-
- // create a new blank image
- dst := imaging.New(100*len(thumbnails), 100, color.NRGBA{0, 0, 0, 0})
-
- // paste thumbnails into the new image side by side
- for i, thumb := range thumbnails {
- dst = imaging.Paste(dst, thumb, image.Pt(i*100, 0))
- }
-
- // save the combined image to file
- err := imaging.Save(dst, "dst.jpg")
- if err != nil {
- panic(err)
- }
+ // Open the test image.
+ src, err := imaging.Open("testdata/lena_512.png")
+ if err != nil {
+ log.Fatalf("Open failed: %v", err)
+ }
+
+ // Crop the original image to 350x350px size using the center anchor.
+ src = imaging.CropAnchor(src, 350, 350, imaging.Center)
+
+ // Resize the cropped image to width = 256px preserving the aspect ratio.
+ src = imaging.Resize(src, 256, 0, imaging.Lanczos)
+
+ // Create a blurred version of the image.
+ img1 := imaging.Blur(src, 2)
+
+ // Create a grayscale version of the image with higher contrast and sharpness.
+ img2 := imaging.Grayscale(src)
+ img2 = imaging.AdjustContrast(img2, 20)
+ img2 = imaging.Sharpen(img2, 2)
+
+ // Create an inverted version of the image.
+ img3 := imaging.Invert(src)
+
+ // Create an embossed version of the image using a convolution filter.
+ img4 := imaging.Convolve3x3(
+ src,
+ [9]float64{
+ -1, -1, 0,
+ -1, 1, 1,
+ 0, 1, 1,
+ },
+ nil,
+ )
+
+ // Create a new image and paste the four produced images into it.
+ dst := imaging.New(512, 512, color.NRGBA{0, 0, 0, 0})
+ dst = imaging.Paste(dst, img1, image.Pt(0, 0))
+ dst = imaging.Paste(dst, img2, image.Pt(0, 256))
+ dst = imaging.Paste(dst, img3, image.Pt(256, 0))
+ dst = imaging.Paste(dst, img4, image.Pt(256, 256))
+
+ // Save the resulting image using JPEG format.
+ err = imaging.Save(dst, "testdata/out_example.jpg")
+ if err != nil {
+ log.Fatalf("Save failed: %v", err)
+ }
}
```
+
+Output:
+
+
\ No newline at end of file |