Sending an Image response

[ShayBox]

I'm trying to return an image/png response, the only reference I could find was a single change log but I still can't get it to work

use color_processing::Color;
use image::{EncodableLayout, ImageBuffer, Rgba};
use poem::{http::StatusCode, Result};
use poem_openapi::{param::Path, payload::Binary, ApiResponse, OpenApi};

#[derive(ApiResponse)]
enum ImageResponse {
    #[oai(content_type = "image/png", status = 200)]
    Png(Binary<Vec<u8>>),
}

pub struct Route;

#[OpenApi]
impl Route {
    /// Generate a solid color image
    #[oai(path = "/hex/generate/:color/:height/:width", method = "get")]
    async fn hex(
        &self,
        color: Path<String>,
        height: Path<u32>,
        width: Path<u32>,
    ) -> Result<ImageResponse> {
        let Ok(color) = color.0.parse::<Color>() else {
            return Err(poem::Error::from_status(StatusCode::BAD_REQUEST))
        };
        let rgba = Rgba([color.red, color.green, color.blue, color.alpha]);
        let image = ImageBuffer::from_pixel(width.0, height.0, rgba);
        let bytes = image.as_bytes().to_owned();

        Ok(ImageResponse::Png(Binary(bytes)))
    }
}

[sunli829]

I tried it and it works fine, what error are you getting here?

[ShayBox]

I get The image "URL" cannot be displayed because it contains errors. in the browser
The network response is

[sunli829]

You must be encoding the image to the PNG format

    #[oai(path = "/hex/generate/:color/:height/:width", method = "get")]
    async fn hex(
        &self,
        color: Path<String>,
        height: Path<u32>,
        width: Path<u32>,
    ) -> Result<ImageResponse> {
        let Ok(color) = color.0.parse::<Color>() else {
              return Err(poem::Error::from_status(StatusCode::BAD_REQUEST))
          };
        let rgba = Rgba([color.red, color.green, color.blue, color.alpha]);
        let image = ImageBuffer::from_pixel(width.0, height.0, rgba);

        let mut png_bytes = Vec::new();
        image
            .write_to(&mut std::io::Cursor::new(&mut png_bytes), ImageFormat::Png)
            .map_err(InternalServerError)?;
        Ok(ImageResponse::Png(Binary(png_bytes)))
    }

[ShayBox]

Thank you that was the problem 👍