Tips on How to Use the [Decal Uploader] Feature
11/09/2017
What is the Decal Uploader?
The Decal Uploader is a feature that allows user-created decals (stickers) to be uploaded on the 'Community' section of
gran-turismo.com, so they can be used within the Livery Editor in-game. The decal file must be in SVG format and no larger than 15kb in size.
What is an SVG file?
Image data used on computers can come as Bitmap data (BMP) or Vector data (SVG). Images in SVG file format can be enlarged or reduced in size without any loss of image quality.
The difference between Bitmap data and Vector data
The BMP format generates an image using groups of dots. If this type of data is enlarged, the small dots will start to be stretched, making edges of curves jagged or blurred.
On the other hand, the SVG format converts images to numbers when storing them. The advantage of vector data is that even if an image is enlarged, the image quality will not deteriorate, and the data size will not increase either.
The diagram below shows a comparison of an enlarged BMP file (left) and a SVG file (right). On the SVG file, the sharpness of the edges is maintained.
Bitmap data
Vector data
Editing SVG files
The data size of a SVG file depends on how the image is created, even if the end results may look identical. If an SVG file size is too large and the image cannot be uploaded, you can reduce its size by editing the anchor points and path data of the SVG image. Specialised optimisation software for SVG files can also be effective in these instances.
Comparison between efficient data and inefficient data
Let’s take a look at a comparison of two SVG files generating the same image.
On the left there's an SVG file that was generated automatically using a non-structured Bitmap image (a collection of dots) as a base, using the auto trace feature of an editing software: unnecessary anchor points can be clearly seen, and they are not accurate either. As a consequence, the file size becomes large.
On the right there's an industry standard SVG file created by manually editing vector data of a Bézier curve: it consists of the least number of anchor points, and each applied with high accuracy. Because of this, its file size is also small.
An SVG file created using an auto trace feature
An SVG file structured with the least number of anchor points
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