diff options
Diffstat (limited to 'vendor/github.com/disintegration/imaging/README.md')
| -rw-r--r-- | vendor/github.com/disintegration/imaging/README.md | 63 |
1 files changed, 30 insertions, 33 deletions
diff --git a/vendor/github.com/disintegration/imaging/README.md b/vendor/github.com/disintegration/imaging/README.md index f957c3e79..c7ee30fc8 100644 --- a/vendor/github.com/disintegration/imaging/README.md +++ b/vendor/github.com/disintegration/imaging/README.md @@ -2,19 +2,16 @@ [](https://godoc.org/github.com/disintegration/imaging)
[](https://travis-ci.org/disintegration/imaging)
-[](https://coveralls.io/github/disintegration/imaging?branch=master)
+[](https://coveralls.io/github/disintegration/imaging?branch=master)
+[](https://goreportcard.com/report/github.com/disintegration/imaging)
-Package imaging provides basic image manipulation functions (resize, rotate, flip, crop, etc.).
-This package is based on the standard Go image package and works best along with it.
+Package imaging provides basic image processing functions (resize, rotate, crop, brightness/contrast adjustments, etc.).
-Image manipulation functions provided by the package take any image type
-that implements `image.Image` interface as an input, and return a new image of
-`*image.NRGBA` type (32bit RGBA colors, not premultiplied by alpha).
+All the image processing functions provided by the package accept any image type that implements `image.Image` interface
+as an input, and return a new image of `*image.NRGBA` type (32bit RGBA colors, not premultiplied by alpha).
## Installation
-Imaging requires Go version 1.2 or greater.
-
go get -u github.com/disintegration/imaging
## Documentation
@@ -46,19 +43,19 @@ Imaging supports image resizing using various resampling filters. The most notab - `Box` - Simple and fast averaging filter appropriate for downscaling. When upscaling it's similar to NearestNeighbor.
- `Linear` - Bilinear filter, smooth and reasonably fast.
- `MitchellNetravali` - А smooth bicubic filter.
-- `CatmullRom` - A sharp bicubic filter.
+- `CatmullRom` - A sharp bicubic filter.
- `Gaussian` - Blurring filter that uses gaussian function, useful for noise removal.
-- `Lanczos` - High-quality resampling filter for photographic images yielding sharp results, but it's slower than cubic filters.
+- `Lanczos` - High-quality resampling filter for photographic images yielding sharp results, slower than cubic filters.
The full list of supported filters: NearestNeighbor, Box, Linear, Hermite, MitchellNetravali, CatmullRom, BSpline, Gaussian, Lanczos, Hann, Hamming, Blackman, Bartlett, Welch, Cosine. Custom filters can be created using ResampleFilter struct.
**Resampling filters comparison**
-The original image.
+Original image:
-
+
-The same image resized from 512x512px to 128x128px using different resampling filters.
+The same image resized from 600x400px to 150x100px using different resampling filters.
From faster (lower quality) to slower (higher quality):
Filter | Resize result
@@ -79,7 +76,7 @@ Sigma parameter allows to control the strength of the blurring effect. Original image | Sigma = 0.5 | Sigma = 1.5
-----------------------------------|----------------------------------------|---------------------------------------
- |  | 
+ |  | 
### Sharpening
@@ -91,7 +88,7 @@ dstImage := imaging.Sharpen(srcImage, 0.5) Original image | Sigma = 0.5 | Sigma = 1.5
-----------------------------------|-------------------------------------------|------------------------------------------
- |  | 
+ |  | 
### Gamma correction
@@ -101,7 +98,7 @@ dstImage := imaging.AdjustGamma(srcImage, 0.75) Original image | Gamma = 0.75 | Gamma = 1.25
-----------------------------------|------------------------------------------|-----------------------------------------
- |  | 
+ |  | 
### Contrast adjustment
@@ -109,9 +106,9 @@ Original image | Gamma = 0.75 | dstImage := imaging.AdjustContrast(srcImage, 20)
```
-Original image | Contrast = 10 | Contrast = -10
+Original image | Contrast = 15 | Contrast = -15
-----------------------------------|--------------------------------------------|-------------------------------------------
- |  | 
+ |  | 
### Brightness adjustment
@@ -121,7 +118,7 @@ dstImage := imaging.AdjustBrightness(srcImage, 20) Original image | Brightness = 10 | Brightness = -10
-----------------------------------|----------------------------------------------|---------------------------------------------
- |  | 
+ |  | 
## Example code
@@ -137,20 +134,20 @@ import ( )
func main() {
- // Open the test image.
- src, err := imaging.Open("testdata/lena_512.png")
+ // Open a test image.
+ src, err := imaging.Open("testdata/flowers.png")
if err != nil {
- log.Fatalf("Open failed: %v", err)
+ log.Fatalf("failed to open image: %v", err)
}
- // Crop the original image to 350x350px size using the center anchor.
- src = imaging.CropAnchor(src, 350, 350, imaging.Center)
+ // Crop the original image to 300x300px size using the center anchor.
+ src = imaging.CropAnchor(src, 300, 300, imaging.Center)
- // Resize the cropped image to width = 256px preserving the aspect ratio.
- src = imaging.Resize(src, 256, 0, imaging.Lanczos)
+ // Resize the cropped image to width = 200px preserving the aspect ratio.
+ src = imaging.Resize(src, 200, 0, imaging.Lanczos)
// Create a blurred version of the image.
- img1 := imaging.Blur(src, 2)
+ img1 := imaging.Blur(src, 5)
// Create a grayscale version of the image with higher contrast and sharpness.
img2 := imaging.Grayscale(src)
@@ -172,16 +169,16 @@ func main() { )
// 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.New(400, 400, 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))
+ dst = imaging.Paste(dst, img2, image.Pt(0, 200))
+ dst = imaging.Paste(dst, img3, image.Pt(200, 0))
+ dst = imaging.Paste(dst, img4, image.Pt(200, 200))
- // Save the resulting image using JPEG format.
+ // Save the resulting image as JPEG.
err = imaging.Save(dst, "testdata/out_example.jpg")
if err != nil {
- log.Fatalf("Save failed: %v", err)
+ log.Fatalf("failed to save image: %v", err)
}
}
```
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