downsize

downsize

Reduces an image to a specified file size in bytes.

Installation

$ go get -u github.com/lelenanam/downsize/...

Usage

You can specify the size in bytes and the format for the output file. For jpeg format, you can specify the quality.

Usage of downsize:
downsize [-s=size] [-f=format] [-q=jpeg quality] [-i=infile] [-o=outfile]
  -f string
    	format: jpeg, png or gif, by default the format of an image is determined during decoding
  -i string
    	input file name, required
  -o string
    	output file name, required
  -q int
    	desired output jpeg quality, ranges from 1 to 100 inclusive, higher is better (default 80)
  -s int
    	desired output file size in bytes (default 204800)

Example

Resize the file image.jpg to size 1 MB and save the result in jpeg format file resized.jpg.

$ downsize -s=1048576 -f=jpeg image.jpg resized.jpg

Sample 1

The original image 2.4 MB:

Downsize to 1 MB, auto determine format for result image:

$ downsize -s=1048576 flower.jpg flower1mb.jpg

Resized result:

Downsize to 200 KB, jpeg format for result image:

$ downsize -s=204800 -f=jpeg flower.jpg flower200kb.jpg

Resized result:

Downsize to 200 KB, png format for result image:

$ downsize -s=204800 -f=png flower.jpg flower200kb.png

Resized result:

Sample 2

The original image 3.4 MB:

Downsize to 200 KB, auto determine format for result image, default quality:

$ downsize -s=204800 leaves.jpg leaves200kb.jpg

Resized result:

Downsize to 200 KB, auto determine format for result image, quality 50:

$ downsize -s=204800 -q=50 leaves.jpg leaves200kbQ50.jpg

Resized result:

Downsize to 100 KB, auto determine format for result image:

$ downsize -s=102400 leaves.jpg leaves100kb.jpg

Resized result: