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pub type ImageInformation {
ImageInformation(width: Int, height: Int, extension: String)
}
pub fn get_image_information(image) {
case image {
<<0x89, "PNG\r\n":utf8, 0x1A, "\n":utf8, _rest:bits>> ->
parse_png_chunks(image, 8)
<<
"GIF":utf8,
_version:bytes-3,
width:little-16,
height:little-16,
_rest:bits,
>> -> Ok(ImageInformation(width, height, "gif"))
_ -> Error("Unsupported image format")
}
}
fn parse_png_chunks(image, offset) {
case image {
<<
_:unit(8)-size(offset),
_length:32,
"IHDR":utf8,
width:32,
height:32,
_rest:bits,
>> -> Ok(ImageInformation(width, height, "png"))
<<_:size(offset), length:32, _:4, _:bits>> ->
parse_png_chunks(image, offset + length + 12)
_ -> Error("Invalid PNG chunk")
}
}
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