How to get background color of a png image?

[zhifengzhuang]

I use identify -verbose to get background color.
Is there any way to get png background color using libvips?

[jcupitt]

I added a thing to git master libvips to read out background. You now see:

$ vipsheader -a audi-8.png 
audi-8.png: 2500x2500 ushort, 3 bands, rgb16, pngload
width: 2500
height: 2500
bands: 3
format: ushort
coding: none
interpretation: rgb16
xoffset: 0
yoffset: 0
xres: 200
yres: 200
filename: audi-8.png
vips-loader: pngload
background: 255 255 255 

Thanks for the suggestion.

[zhifengzhuang]

hello again @jcupitt.Is gif supported?I can get background color using magickwand.

[jcupitt]

I added bg for gifload as well.

$ vipsheader -a 3198.gif 
temp-0: 298x193 uchar, 3 bands, srgb, gifload
width: 298
height: 193
bands: 3
format: uchar
coding: none
interpretation: srgb
xoffset: 0
yoffset: 0
xres: 1
yres: 1
filename: temp-0
vips-loader: gifload
n-pages: 139
loop: 0
delay: 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30 30
background: 104 54 42 

[jcupitt]

Off-topic, but please don't post screenshots. Just copy-paste the text and put it in triple backticks, eg.:

    ```C
    int this_is = some( C_code );
    ```

Displays as:

int this_is = some( C_code );

See: https://guides.github.com/features/mastering-markdown/

[zhifengzhuang]

I will pay attention to it later.Thanks for your reply!