Goose Goose - 5 months ago 23
Javascript Question

Create static png from svg without Anti-aliasing, with or without canvas

What I want

I want to take a vector SVG image and create a raster png from it without Anti-aliasing. The svg will be dynamically generated based on user input (text, bold, font-family). png is preferred, but other raster formats can be accepted.

What I am trying

var svg = '<svg><g><text>Hello World</text></g></svg>';
var img = document.createElement('img');
img.setAttribute('src','data:image/svg+xml;base64,' + btoa(svg_static_data) );
img.onload = function() {
ctx.drawImage(img, 0, 0);
ctx.mozImageSmoothingEnabled = false;
ctx.webkitImageSmoothingEnabled = false;
ctx.msImageSmoothingEnabled = false;
ctx.imageSmoothingEnabled = false;
static_image = canvas.toDataURL('image/png');
};


The svg here is very simple simply for demonstration. Here, I turn the svg into a canvas element, and turn the canvas element into an image. When that resulted in Anti-aliasing, the only configuration I found that might help was
imageSmoothingEnabled
, however I am still getting Anti-aliasing, likely because that configuration is for elements drawn with canvas itself. I have also tried placing that configuration above
drawImage
, but no luck.

What I need

A function to turn a dynamic non-animated SVG, that may contain many elements and attributes, including curved text, into a raster image that is at least mostly identical.

K3N K3N
Answer

imageSmoothingEnabled do only apply to images, but only when the image source is drawn scaled.

However, the problem in this case is that the SVG image is anti-aliased internally when rasterized before your onload handler kicks in, so when you draw it to canvas it is already anti-aliased - there is nothing you can do to turn this off except by manually parsing and rendering the SVG (which is not a small project).

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