How to replace white background color with transparent of an image in ImageMagick?

Question

I have an image in .jpg format with white background color. I want to remove the white background color to transparent in Imagemagick.

Answer 1

You cannot have transparent background colors in your JPEGs. The JPEG file format doesn't support transparency.

If you need transparent background, you need to convert the JPEG to

• either PNG (high quality, filesize possibly larger than JPEG)
• or GIF (in case you can tolerate low quality and a range of maximally 255 colors).

Example command:

convert  your.jpg  -transparent white  your.png

Answer 2

This is my solution without magicwand (replace magick by convert for im < 7.0):

magick img.png -fuzz 20% -fill none -draw "alpha 1x1 floodfill" result.png

Answer 3

I just found a very neat thing!

magicwand 1,1 -t 20 -f image -r outside -m overlay -o 0 image.jpg imgOutput.png

It is a Fred Weinhaus bash script that can be downloaded from here (for non commercial use only). Also there has about 250 scripts!! and this one is amazing! it did exactly the trick, to remove all background while keeping the inner image dots untouched!

At his page, there are several images as examples so you pick what you need to put on the command line!

The initial position 1,1 is a general guesser saying all the contour is background.

Pay attention that the output must be ".png"

Answer 4

First, you need to convert the image format from .jpg to .png format, because JPEG does not support transparency. Then use this command:

convert image1.png -fuzz 20% -transparent white result.png

The -fuzz option allows the specified percentage deviation from the pure white colour to be converted to transparent as well. This is useful, for example, when your image contains noise or subtle gradients.