README
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Bounding box
Library for finding the minimum bounding box of an image. It does so by simply iterating the image and checking which pixels surpass certain threshold, so they are considered as data points in the image which will delimit the bounding box.
Usage
package main
import (
"image"
_ "image/png"
"os"
"github.com/flesnuk/boundingbox"
)
func main() {
infile, _ := os.Open("0004-001.png")
defer infile.Close()
img, _ := image.Decode(infile)
bbox := boundingbox.Find(img, boundingbox.NewConfig(color.Gray{30}))
}
The NewConfig helper is useful for creating a configuration with the specified threshold color. By default the function used to compare the pixels is defined and exported as PixHasDataBlackBG. This does a simple comparison of RGB values, and if all are greater than the color threshold, it returns true.
There is a few options that can be customized:
- PixHasData: set custom function to compare when a pixel is considered as data or not.
- Bounds: by default uses the image bounds, but can be changed with this parameter.
- Parallel: sets the number of goroutines to process the image in parallel. Set to -1 for auto setting (use the runtime.NumCPU())
Documentation
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Index ¶
Constants ¶
const ParallelAuto = -1
Variables ¶
This section is empty.
Functions ¶
func PixHasDataBlackBG ¶
PixHasDataBlackBG is a simple function that returns true if pix has greater RGB values than threshold.
Types ¶
type Config ¶
type Config struct {
// When a pixel is considered as the edge of the image (has meaningful data).
Threshold color.RGBA64
// Check if pixel surpasses the Threshold. If nil it will use a basic pix > threshold function (gray-like comparison).
PixHasData func(pix color.RGBA64, threshold color.RGBA64) bool
// Region to check, if empty, image bounds are used instead.
Bounds image.Rectangle
// Number of gorutines used if n > 1. Use ParallelAuto (-1) for using NumCPU
Parallel int
}
Config contains the parameters used.
func NewConfig ¶
NewConfig returns a default config using the supplied threshold color. The PixHasData function is nil and use a basic pix > threshold function (gray-like comparison).
func NewConfigInverse ¶
NewConfigInverse returns a default config using the supplied threshold color. The PixHasData function use a basic pix < threshold function. Useful when background color is white.
func (*Config) WithBounds ¶
WithBounds sets the bounds region.
func (*Config) WithParallel ¶
WithParallel sets the parallel number of goroutines.
Source Files
Directories