fix: ocr luminance calculation fix

Author: hrideshmg

src/rust/src/hardsubx/imgops.rs

@@ -1,8 +1,8 @@
-use palette::{FromColor, Hsv, Lab, Srgb};
+use palette::{FromColor, Hsv, Lab, LinSrgb};
 
 #[no_mangle]
 pub extern "C" fn rgb_to_hsv(R: f32, G: f32, B: f32, H: &mut f32, S: &mut f32, V: &mut f32) {
-    let rgb = Srgb::new(R, G, B);
+    let rgb = LinSrgb::new(R, G, B);
 
     let hsv_rep = Hsv::from_color(rgb);
 
@@ -14,7 +14,7 @@ pub extern "C" fn rgb_to_hsv(R: f32, G: f32, B: f32, H: &mut f32, S: &mut f32, V
 #[no_mangle]
 pub extern "C" fn rgb_to_lab(R: f32, G: f32, B: f32, L: &mut f32, a: &mut f32, b: &mut f32) {
     // Normalize input RGB from 0-255 to 0.0-1.0
-    let rgb = Srgb::new(R / 255.0, G / 255.0, B / 255.0);
+    let rgb = LinSrgb::new(R / 255.0, G / 255.0, B / 255.0);
 
     // Convert from sRGB to Lab (D65 white point is default)
     let lab_rep = Lab::from_color(rgb);