Como criar capturas de imagem transparentes?

É possível fornecer capturas de imagens de HTML e capturas de tela de URLs com fundo transparente. No entanto, isso só funcionará se o fundo do HTML capturado for transparente e o formato da imagem for PNG ou TIFF. Se você usar um formato de imagem diferente de PNG ou TIFF, obterá um fundo preto.

Para que um documento HTML tenha um fundo transparente, a propriedade CSS background deve ser definida como transparente tanto para o html e body tags conforme mostrado nos exemplos abaixo.

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GrabzItClient grabzIt = new GrabzItClient("Sign in to view your Application Key", "Sign in to view your Application Secret");
ImageOptions options = new ImageOptions();
options.Format = ImageFormat.png;
options.Transparent = true;
grabzIt.HTMLToImage("<html><head><style>html,body{background:transparent}</style></head><body><h1>Hello World!</h1></body></html>"
, options);
grabzIt.SaveTo("result.png");

GrabzItClient grabzIt = new GrabzItClient("Sign in to view your Application Key", "Sign in to view your Application Secret");
ImageOptions options = new ImageOptions();
options.setFormat(ImageFormat.PNG);
options.setTransparent(true);
grabzIt.HTMLToImage("<html><head><style>html,body{background:transparent}</style></head><body><h1>Hello World!</h1></body></html>"
, options);
grabzIt.SaveTo("result.png");

<script src="https://cdn.jsdelivr.net/npm/@grabzit/js@3.5.2/grabzit.min.js"></script>
<script>
GrabzIt("Sign in to view your Application Key").ConvertHTML(
"<html><head><style>html,body{background:transparent}</style></head><body><h1>Hello World!</h1></body></html>",
{"format":"png","transparent":1}).Create();
</script>

var grabzit = require('grabzit');

var client = new grabzit("Sign in to view your Application Key", "Sign in to view your Application Secret");
client.html_to_image("<html><head><style>html,body{background:transparent}</style></head><body><h1>Hello World!</h1></body></html>",
{"format":"png","transparent":1});
client.save_to("result.png", function (error, id){
    if (error != null){
        throw error;
    }
});

$grabzIt = GrabzItClient->new("Sign in to view your Application Key", "Sign in to view your Application Secret");
$options = GrabzItImageOptions->new();
$options->format("png");
$options->transparent(1);
$grabzIt->HTMLToImage("<html><head><style>html,body{background:transparent}</style></head><body><h1>Hello World!</h1></body></html>", 
$options);
$grabzIt->SaveTo("result.png");

$grabzIt = new \GrabzIt\GrabzItClient("Sign in to view your Application Key", "Sign in to view your Application Secret");
$options = new \GrabzIt\GrabzItImageOptions();
$options->setFormat("png");
$options->setTransparent(true);
$grabzIt->HTMLToImage("<html><head><style>html,body{background:transparent}</style></head><body><h1>Hello World!</h1></body></html>",
$options);
$grabzIt->SaveTo("result.png");

grabzIt = GrabzItClient.GrabzItClient("Sign in to view your Application Key", "Sign in to view your Application Secret")
options = GrabzItImageOptions.GrabzItImageOptions()
options.format = "png"
options.transparent = True
grabzIt.HTMLToImage("<html><head><style>html,body{background:transparent}</style></head><body><h1>Hello World!</h1></body></html>",
options)
grabzIt.SaveTo("result.png")

    curl 
    -d key=Sign in to view your Application Key
    -d format=png
    -d transparent=1
    -d html=%3Chtml%3E%3Chead%3E%3Cstyle%3Ehtml%2Cbody%7Bbackground%3Atransparent%7D%3C%2Fstyle%3E%3C%2Fhead%3E%3Cbody%3E%3Ch1%3EHello%20World%21%3C%2Fh1%3E%3C%2Fbody%3E%3C%2Fhtml%3E
    https://api.grabz.it/services/convert

grabzIt = GrabzIt::Client.new("Sign in to view your Application Key", "Sign in to view your Application Secret")
options = GrabzIt::ImageOptions.new()
options.format = "png"
options.transparent = true
grabzIt.html_to_image("<html><head><style>html,body{background:transparent}</style></head><body><h1>Hello World!</h1></body></html>",
options)
grabzIt.save_to("result.png")

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