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PNG image has a black background after resizing with im.

Posted: 2009-12-18T11:10:55-07:00
by janekyun
I have a png image which opens in IE6 with a white background but after using resize the png opens with the black background.
I am using the following command to resize the image.
convert Tara-Cell1_2.png -resize 640x480 Tara-Cell1_22.png

Any replies appreciated.

Re: PNG image has a black background after resizing with im.

Posted: 2009-12-18T11:17:56-07:00
by fmw42
does your png have any transparency or alpha channel?

identify -verbose Tara-Cell1_2.png

Re: PNG image has a black background after resizing with im.

Posted: 2009-12-18T11:42:35-07:00
by janekyun
I am posting only the alpha values
for Image: Tara-Cell1_2.png
Alpha: rgba(255,255,255,0) #FFFFFF00

for Image: Tara-Cell1_22.png
Alpha: rgba(35,31,32,0) #231F2000

Thanks.

Re: PNG image has a black background after resizing with im.

Posted: 2009-12-18T12:09:01-07:00
by fmw42
try

convert Tara-Cell1_2.png -channel rgba -alpha on -resize 640x480 Tara-Cell1_22.png

Re: PNG image has a black background after resizing with im.

Posted: 2009-12-18T12:58:14-07:00
by janekyun
Sorry it did not work.
Image Tara-Cell1_22.png still has the old alpha.

Re: PNG image has a black background after resizing with im.

Posted: 2009-12-18T17:45:13-07:00
by fmw42
can you post a link to Tara-Cell1_2.png so others can examine it and try to convert it.

Also what version of IM are you using? If too old, perhaps you should upgrade.