Transparency support with PNGs in conversions

[ehsanquddusi]

I am writing a register a mediaCollection for a model. The issue I am facing is that during the conversion, the transparency is lost in the converted image. How can I resize the image without losing transparency in result image?

Here is the code that I am using

    public function registerMediaCollections(): void
    {
        $this->addMediaCollection('crops')
            ->singleFile()
            ->useDisk('public')
            ->acceptsMimeTypes([
                'image/jpeg', 'image/png', 'image/jpg',
            ])
            ->onlyKeepLatest(1)
            ->registerMediaConversions(function (Media $media) {
                $this
                    ->addMediaConversion('thumb')
                    ->fit(Manipulations::FIT_CROP, 150, 150)
                    ->keepOriginalImageFormat();
            });
    }