[FFmpeg-user] White is not pure white in overlay of PNG on JPEG image

[Paul B Mahol]

On 10/9/19, Jason Green <jason.green at threadsstyling.com> wrote:
> Ok so I get that png doesn't have a colourspace, so do I need to specify a
> colorspace for the input? Plus I need to specify the output I am guessing.
> I have tried outputting with various colorspace and color_range values but
> I'm having no luck. Do I need to just keep experimenting with these values?
>

colorspace in this context: jpg is yuv ang png is rgb.

>
> On Wed, 9 Oct 2019 at 12:19, Paul B Mahol <onemda at gmail.com> wrote:
>
>> On 10/9/19, Jason Green <jason.green at threadsstyling.com> wrote:
>> > I'm sorry to bother you all with this but I have been unable to resolve
>> the
>> > issue with my own research (which is really rare for me :) ).
>> >
>> > I am trying to overlay pngs of text that have been generated by another
>> > source onto jpg photos. I have simplified the command down to it's
>> simplest
>> > example and I am using public images so you can even try the command
>> > yourself.
>> >
>> > ffmpeg -y -i "
>> > https://asset-info-examples.s3-eu-west-1.amazonaws.com/white-text-bg.jpg
>> "
>> > -i "
>> https://asset-info-examples.s3-eu-west-1.amazonaws.com/white-text.png"
>> > -movflags faststart -filter_complex "[0][1]overlay=x=131:y=300" -q:v 6
>> > -f
>> > image2 -codec:v mjpeg test_remote.jpg
>> >
>> > The white text png has perfectly white pixels in the original, but in
>> > the
>> > final they are slightly grey. I have tried various options using format
>> but
>> > I can't manage to get it to work.
>> >
>> > Any suggestions would be appreciated.
>>
>> Avoid implicit colorspace conversion, and do it explicitly.
>>
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>
>
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