dequantizing splines (#66)

* Added noise stage.

* dequantizing splines

Co-authored-by: Martin Bruse <zond@google.com>

* delete consts

* Added point position sanity check.

* more validate_spline_pos

* Added spline sanity test based on numbers generated by libjxl.

* test reading headers of all testfiles (#64)


Co-authored-by: Luca Versari <veluca93@gmail.com>

* dequantizing splines

Co-authored-by: Martin Bruse <zond@google.com>

* delete consts

* Added point position sanity check.

* more validate_spline_pos

* Added spline sanity test based on numbers generated by libjxl.

* Update README.md (#67)

* Fixed PR comments.

* Modular mode: apply transforms to channel shapes.

---------

Co-authored-by: Martin Bruse <zondolfin@gmail.com>
Co-authored-by: Martin Bruse <zond@google.com>
Co-authored-by: Luca Versari <veluca93@gmail.com>

jxl/src/error.rs

@@ -111,10 +111,18 @@ pub enum Error {
     InvalidPredictor(u32),
     #[error("Invalid modular mode property: {0}")]
     InvalidProperty(u32),
+    #[error("Too large area for spline: {0}, limit is {1}")]
+    SplinesAreaTooLarge(u64, u64),
+    #[error("Too large manhattan_distance reached: {0}, limit is {1}")]
+    SplinesDistanceTooLarge(u64, u64),
     #[error("Too many splines: {0}, limit is {1}")]
     SplinesTooMany(u32, u32),
     #[error("Too many control points for splines: {0}, limit is {1}")]
     SplinesTooManyControlPoints(u32, u32),
+    #[error(
+        "Spline point outside valid bounds: coordinates: {0:?}, out of bounds: {1}, bounds: {2:?}"
+    )]
+    SplinesPointOutOfRange((i32, i32), i32, std::ops::Range<i32>),
     #[error("Spline coordinates out of bounds: {0}, limit is {1}")]
     SplinesCoordinatesLimit(i32, i32),
     #[error("Spline delta-delta is out of bounds: {0}, limit is {1}")]