png: Add CICP support

gufo-common/src/cicp.rs

@@ -5,6 +5,7 @@
 use crate::utils;
 
 /// Coding-independent code point
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct Cicp {
     pub colour_primaries: ColourPrimaries,
     pub transfer_characteristics: TransferCharacteristics,
@@ -42,7 +43,7 @@ impl Cicp {
 
 utils::convertible_enum!(
     #[repr(u8)]
-    #[derive(Debug, PartialEq, Eq)]
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
     pub enum ColourPrimaries {
         Srgb = 1,
         Unspecified = 2,
@@ -53,17 +54,19 @@ utils::convertible_enum!(
 
 utils::convertible_enum!(
     #[repr(u8)]
-    #[derive(Debug, PartialEq, Eq)]
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
     pub enum TransferCharacteristics {
         /// Standard dynamic range
-        Sdr = 1,
+        Gamma22 = 1,
         Unspecified = 2,
         /// Standard dynamic range 10 bit
-        Sdr_ = 6,
+        Gamma22_ = 6,
+        /// Gamma=2.4 curve per IEC 61966-2-1 sRGB
+        Gamma24 = 13,
         /// Standard dynamic range 10 bit
-        Sdr10 = 14,
+        Gamma22Bit10 = 14,
         /// Standard dynamic range 12 bit
-        Sdr12 = 15,
+        Gamma22Bit12 = 15,
         /// Perceptual quantization (PQ) system
         Pq = 16,
         /// Hybrid log-gamma (HLG) system
@@ -73,7 +76,7 @@ utils::convertible_enum!(
 
 utils::convertible_enum!(
     #[repr(u8)]
-    #[derive(Debug, PartialEq, Eq)]
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
     pub enum MatrixCoefficients {
         Identity = 0,
         Unspecified = 2,
@@ -83,7 +86,7 @@ utils::convertible_enum!(
 
 utils::maybe_convertible_enum!(
     #[repr(u8)]
-    #[derive(Debug, PartialEq, Eq)]
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
     pub enum VideoRangeFlag {
         Narrow = 0,
         Full = 1,

gufo-png/src/chunk_type.rs

@@ -26,6 +26,9 @@ gufo_common::utils::convertible_enum!(
         eXIf = b(b"eXIf"),
         /// Embedded ICC profile
         iCCP = b(b"iCCP"),
+        /// Coding-independent code points
+        cICP = b(b"cICP"),
+
         /// Apple proprietary, information for faster image loading
         ///
         /// See <https://www.hackerfactor.com/blog/index.php?/archives/895-Connecting-the-iDOTs.html>

gufo-png/src/png.rs

@@ -2,6 +2,8 @@ use std::io::{Cursor, Read};
 use std::ops::Range;
 use std::slice::SliceIndex;
 
+use gufo_common::cicp::Cicp;
+
 pub use super::*;
 
 pub const MAGIC_BYTES: &[u8] = &[137, 80, 78, 71, 13, 10, 26, 10];
@@ -86,6 +88,15 @@ impl Png {
         }
     }
 
+    pub fn cicp(&self) -> Option<Cicp> {
+        let cicp_raw = self
+            .chunks()
+            .into_iter()
+            .find(|x| x.chunk_type() == ChunkType::cICP)?;
+
+        Cicp::from_bytes(cicp_raw.chunk_data().get(0..4)?.try_into().ok()?).ok()
+    }
+
     /// List all chunks in the data
     fn find_chunks(data: &[u8]) -> Result<Vec<RawChunk>, Error> {
         let mut cur = Cursor::new(data);
@@ -221,3 +232,24 @@ impl Png {
             .ok_or(Error::IndexNotInData(index))
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use gufo_common::cicp::*;
+
+    #[test]
+    fn x() {
+        let data = std::fs::read("../test-images/images/cicp-p3/cicp-p3.png").unwrap();
+        let png = crate::Png::new(data).unwrap();
+        dbg!(png.cicp());
+        assert_eq!(
+            png.cicp(),
+            Some(Cicp {
+                colour_primaries: ColourPrimaries::DciP3,
+                transfer_characteristics: TransferCharacteristics::Gamma24,
+                matrix_coefficients: MatrixCoefficients::Identity,
+                video_full_range_flag: VideoRangeFlag::Full,
+            })
+        );
+    }
+}