doc+api: cleanup visibility for API

14 files changed, 149 insertions, 133 deletions

diff --git a/benches/the_benchmark.rs b/benches/the_benchmark.rs
index f25edca..bf7c86d 100644
--- a/benches/the_benchmark.rs
+++ b/benches/the_benchmark.rs
@@ -83,7 +83,7 @@ fn ljpeg_benchmark(c: &mut Criterion) {
             let mut decompressor = LJpeg::new();
             let io = std::fs::File::open("test/ljpegtest1.jpg").expect("Couldn't open");
             let mut buffered = std::io::BufReader::new(io);
-            let _ = decompressor.decompress(&mut buffered);
+            let _ = decompressor.discard_decompress(&mut buffered);
         });
     });
 }
diff --git a/src/bin/fuzz-ljpeg.rs b/src/bin/fuzz-ljpeg.rs
index b7df2df..6b19318 100644
--- a/src/bin/fuzz-ljpeg.rs
+++ b/src/bin/fuzz-ljpeg.rs
@@ -9,6 +9,6 @@ fn main() {
     fuzz!(|data: &[u8]| {
         let mut io = std::io::Cursor::new(data);
         let mut decompressor = LJpeg::new();
-        let _ = decompressor.decompress(&mut io);
+        let _ = decompressor.discard_decompress(&mut io);
     });
 }
diff --git a/src/bin/test-ljpeg.rs b/src/bin/test-ljpeg.rs
index a22077d..4d68433 100644
--- a/src/bin/test-ljpeg.rs
+++ b/src/bin/test-ljpeg.rs
@@ -13,7 +13,7 @@ fn main() {
     let io = std::fs::File::open(&args[1]);
     assert!(io.is_ok());
     let mut io = std::io::BufReader::new(io.unwrap());
-    let _ = decompressor.decompress(&mut io).map_err(|e| {
+    let _ = decompressor.discard_decompress(&mut io).map_err(|e| {
         println!("Error decoding: {}", e);
         e
     });
diff --git a/src/bitmap.rs b/src/bitmap.rs
index afd6bf5..ea74dae 100644
--- a/src/bitmap.rs
+++ b/src/bitmap.rs
@@ -26,7 +26,7 @@ use crate::DataType;
 
 /// An image buffer carries the data and the dimension. It is used to
 /// carry pipeline input and ouput as dimensions can change.
-pub struct ImageBuffer<T> {
+pub(crate) struct ImageBuffer<T> {
     pub(crate) data: Vec<T>,
     pub(crate) width: u32,
     pub(crate) height: u32,
@@ -49,7 +49,7 @@ impl<T> ImageBuffer<T> {
     }
 
     /// Return the pixel RGB value at `x` and `y`.
-    pub fn pixel_at(&self, x: u32, y: u32) -> Option<Vec<T>>
+    pub(crate) fn pixel_at(&self, x: u32, y: u32) -> Option<Vec<T>>
     where
         T: Copy,
     {
@@ -64,7 +64,7 @@ impl<T> ImageBuffer<T> {
 }
 
 impl ImageBuffer<f64> {
-    pub fn into_u16(self) -> ImageBuffer<u16> {
+    pub(crate) fn into_u16(self) -> ImageBuffer<u16> {
         ImageBuffer::<u16>::with_data(
             self.data
                 .iter()
@@ -79,7 +79,7 @@ impl ImageBuffer<f64> {
 }
 
 impl ImageBuffer<u16> {
-    pub fn into_f64(self) -> ImageBuffer<f64> {
+    pub(crate) fn into_f64(self) -> ImageBuffer<f64> {
         ImageBuffer::<f64>::with_data(
             self.data
                 .iter()
@@ -108,6 +108,8 @@ pub trait Bitmap {
     fn data8(&self) -> Option<&[u8]>;
 }
 
+/// An `Image` is a more comprehensive `Bitmap` with 16-bits
+/// support.
 pub trait Image: Bitmap {
     /// Image data in 16 bits
     fn data16(&self) -> Option<&[u16]>;
diff --git a/src/decompress/ljpeg.rs b/src/decompress/ljpeg.rs
index c899496..12515eb 100644
--- a/src/decompress/ljpeg.rs
+++ b/src/decompress/ljpeg.rs
@@ -237,8 +237,13 @@ impl LJpeg {
         })
     }
 
-    /// Decompress the LJPEG stream into a RawImage.
-    pub fn decompress(&mut self, reader: &mut dyn ReadAndSeek) -> Result<ImageBuffer<u16>> {
+    #[cfg(any(feature = "fuzzing", feature = "bench"))]
+    /// Used to fuzz or bench the decompressor that is otherwise crate only.
+    pub fn discard_decompress(&mut self, reader: &mut dyn ReadAndSeek) -> Result<()> {
+        self.decompress(reader).map(|_| ())
+    }
+
+    pub(crate) fn decompress(&mut self, reader: &mut dyn ReadAndSeek) -> Result<ImageBuffer<u16>> {
         let tile = self.decompress_buffer(reader, false)?;
         Ok(ImageBuffer::with_data(
             tile.buf,
diff --git a/src/dump.rs b/src/dump.rs
index f495f54..8c4d876 100644
--- a/src/dump.rs
+++ b/src/dump.rs
@@ -23,7 +23,7 @@ macro_rules! dumpfile_impl {
 }
 
 /// Trait to dump a container.
-/// XXX invert the default methods
+// XXX invert the default methods
 pub trait Dump {
     #[cfg(feature = "dump")]
     /// Print dump the container as `indent`
diff --git a/src/olympus/decompress.rs b/src/olympus/decompress.rs
index 199ba44..37f519d 100644
--- a/src/olympus/decompress.rs
+++ b/src/olympus/decompress.rs
@@ -27,7 +27,8 @@ use bitreader::BitReader;
 
 use crate::{Error, Result};
 
-/// Decompress the Olympus raw data.
+#[doc(hidden)]
+/// Decompress the Olympus raw data. Not a public API.
 pub fn decompress_olympus(input: &[u8], w: usize, h: usize) -> Result<Vec<u16>> {
     if input.len() < 8 {
         return Err(Error::Decompression(
diff --git a/src/rawimage.rs b/src/rawimage.rs
index d82a76b..cf032e6 100644
--- a/src/rawimage.rs
+++ b/src/rawimage.rs
@@ -397,7 +397,7 @@ impl RawImage {
         cam_xyz * xyz_rgb
     }
 
-    pub fn colour_correct(
+    pub(crate) fn colour_correct(
         &self,
         mut buffer: ImageBuffer<f64>,
         target: ColourSpace,
diff --git a/src/render/grayscale.rs b/src/render/grayscale.rs
index f0d5e78..d60d25b 100644
--- a/src/render/grayscale.rs
+++ b/src/render/grayscale.rs
@@ -25,7 +25,7 @@ use crate::{Error, Result};
 /// Convert a grayscale buffer to RGB
 ///
 /// It's done naively.
-pub fn to_rgb(buffer: &ImageBuffer<f64>) -> Result<ImageBuffer<f64>> {
+pub(crate) fn to_rgb(buffer: &ImageBuffer<f64>) -> Result<ImageBuffer<f64>> {
     if buffer.cc != 1 {
         return Err(Error::InvalidFormat);
     }
diff --git a/src/thumbnail.rs b/src/thumbnail.rs
index 6b50808..dc239c9 100644
--- a/src/thumbnail.rs
+++ b/src/thumbnail.rs
@@ -99,12 +99,17 @@ impl Default for Thumbnail {
 }
 
 impl Thumbnail {
-    pub fn new() -> Thumbnail {
+    pub(crate) fn new() -> Thumbnail {
         Thumbnail::default()
     }
 
     /// New thumbnail with data.
-    pub fn with_data(width: u32, height: u32, data_type: DataType, data: Vec<u8>) -> Thumbnail {
+    pub(crate) fn with_data(
+        width: u32,
+        height: u32,
+        data_type: DataType,
+        data: Vec<u8>,
+    ) -> Thumbnail {
         Thumbnail {
             width,
             height,
diff --git a/src/tiff.rs b/src/tiff.rs
index 7faab8e..9fafe41 100644
--- a/src/tiff.rs
+++ b/src/tiff.rs
@@ -155,7 +155,7 @@ pub trait Ifd {
     }
 }
 
-pub type MakeToIdMap = std::collections::HashMap<&'static str, TypeId>;
+pub(crate) type MakeToIdMap = std::collections::HashMap<&'static str, TypeId>;
 
 /// Identify a files using the Exif data
 pub(crate) fn identify_with_exif(container: &Container, map: &MakeToIdMap) -> Option<TypeId> {
diff --git a/src/tiff/entry.rs b/src/tiff/entry.rs
index b9c6979..b5b2319 100644
--- a/src/tiff/entry.rs
+++ b/src/tiff/entry.rs
@@ -166,7 +166,7 @@ impl Entry {
     }
 
     /// Get the value at index.
-    pub fn value_at_index<T, E>(&self, index: u32) -> Option<T>
+    pub(crate) fn value_at_index<T, E>(&self, index: u32) -> Option<T>
     where
         T: ExifValue,
         E: ByteOrder,
@@ -256,7 +256,7 @@ impl Entry {
     }
 
     /// Get the value out of the entry, ignoring the type.
-    pub fn value_untyped<T, E>(&self) -> Option<T>
+    pub(crate) fn value_untyped<T, E>(&self) -> Option<T>
     where
         T: ExifValue,
         E: ByteOrder,
@@ -296,7 +296,7 @@ impl Entry {
     }
 
     /// Get the value out of the entry.
-    pub fn value<T, E>(&self) -> Option<T>
+    pub(crate) fn value<T, E>(&self) -> Option<T>
     where
         T: ExifValue,
         E: ByteOrder,
@@ -445,7 +445,7 @@ impl Entry {
     }
 
     /// Get the value array out of the entry, using `endian`.
-    pub fn value_array<T>(&self, endian: Endian) -> Option<Vec<T>>
+    pub(crate) fn value_array<T>(&self, endian: Endian) -> Option<Vec<T>>
     where
         T: ExifValue,
     {
diff --git a/src/tiff/exif.rs b/src/tiff/exif.rs
index 5039f99..cad3cb2 100644
--- a/src/tiff/exif.rs
+++ b/src/tiff/exif.rs
@@ -23,9 +23,9 @@
 
 /// Exif tags constants
 pub(crate) mod generated;
-pub use generated::EXIF_TAG_NAMES as TAG_NAMES;
+pub(crate) use generated::EXIF_TAG_NAMES as TAG_NAMES;
 mod tags;
-pub use tags::*;
+pub(crate) use tags::*;
 
 use std::collections::HashMap;
 
@@ -34,7 +34,7 @@ use num_enum::TryFromPrimitive;
 
 use crate::utils;
 
-pub type TagMap = HashMap<u16, &'static str>;
+pub(crate) type TagMap = HashMap<u16, &'static str>;
 
 /// Type a tag. See `tiff::Entry`.
 #[derive(Debug, PartialEq)]
@@ -87,7 +87,7 @@ impl std::convert::From<TagType> for &'static str {
 }
 
 /// Return the size of a unit for the tag type
-pub fn tag_unit_size(tag_type: TagType) -> usize {
+pub(crate) fn tag_unit_size(tag_type: TagType) -> usize {
     use TagType::*;
 
     match tag_type {
@@ -365,9 +365,9 @@ impl ToString for SRational {
     }
 }
 
-/// Exif photometric interpretation
 #[repr(u16)]
 #[derive(Copy, Clone, Debug, Default)]
+/// Exif photometric interpretation
 pub enum PhotometricInterpretation {
     #[default]
     None = 0,
@@ -398,6 +398,7 @@ impl std::convert::TryFrom<u32> for PhotometricInterpretation {
 
 #[repr(u32)]
 #[derive(Clone, Copy, Debug, PartialEq, TryFromPrimitive)]
+/// Exif light source (Illuminant)
 pub enum LightsourceValue {
     Unknown = 0,
     Daylight = 1,
diff --git a/src/tiff/exif/tags.rs b/src/tiff/exif/tags.rs
index 40e4134..b924cbd 100644
--- a/src/tiff/exif/tags.rs
+++ b/src/tiff/exif/tags.rs
@@ -19,145 +19,147 @@
  * <http://www.gnu.org/licenses/>.
  */
 
-pub const EXIF_TAG_INTEROPERABILITY_INDEX: u16 = 0x0001;
-pub const EXIF_TAG_INTEROPERABILITY_VERSION: u16 = 0x0002;
+// Make values public as soon as they get used.
+
+pub const _EXIF_TAG_INTEROPERABILITY_INDEX: u16 = 0x0001;
+pub const _EXIF_TAG_INTEROPERABILITY_VERSION: u16 = 0x0002;
 pub const EXIF_TAG_NEW_SUBFILE_TYPE: u16 = 0x00fe;
 pub const EXIF_TAG_IMAGE_WIDTH: u16 = 0x0100;
 pub const EXIF_TAG_IMAGE_LENGTH: u16 = 0x0101;
 pub const EXIF_TAG_BITS_PER_SAMPLE: u16 = 0x0102;
 pub const EXIF_TAG_COMPRESSION: u16 = 0x0103;
 pub const EXIF_TAG_PHOTOMETRIC_INTERPRETATION: u16 = 0x0106;
-pub const EXIF_TAG_FILL_ORDER: u16 = 0x010a;
+pub const _EXIF_TAG_FILL_ORDER: u16 = 0x010a;
 pub const EXIF_TAG_DOCUMENT_NAME: u16 = 0x010d;
 pub const EXIF_TAG_IMAGE_DESCRIPTION: u16 = 0x010e;
 pub const EXIF_TAG_MAKE: u16 = 0x010f;
 pub const EXIF_TAG_MODEL: u16 = 0x0110;
 pub const EXIF_TAG_STRIP_OFFSETS: u16 = 0x0111;
 pub const EXIF_TAG_ORIENTATION: u16 = 0x0112;
-pub const EXIF_TAG_SAMPLES_PER_PIXEL: u16 = 0x0115;
-pub const EXIF_TAG_ROWS_PER_STRIP: u16 = 0x0116;
+pub const _EXIF_TAG_SAMPLES_PER_PIXEL: u16 = 0x0115;
+pub const _EXIF_TAG_ROWS_PER_STRIP: u16 = 0x0116;
 pub const EXIF_TAG_STRIP_BYTE_COUNTS: u16 = 0x0117;
-pub const EXIF_TAG_X_RESOLUTION: u16 = 0x011a;
-pub const EXIF_TAG_Y_RESOLUTION: u16 = 0x011b;
-pub const EXIF_TAG_PLANAR_CONFIGURATION: u16 = 0x011c;
-pub const EXIF_TAG_RESOLUTION_UNIT: u16 = 0x0128;
-pub const EXIF_TAG_TRANSFER_FUNCTION: u16 = 0x012d;
-pub const EXIF_TAG_SOFTWARE: u16 = 0x0131;
-pub const EXIF_TAG_DATE_TIME: u16 = 0x0132;
-pub const EXIF_TAG_ARTIST: u16 = 0x013b;
-pub const EXIF_TAG_WHITE_POINT: u16 = 0x013e;
-pub const EXIF_TAG_PRIMARY_CHROMATICITIES: u16 = 0x013f;
+pub const _EXIF_TAG_X_RESOLUTION: u16 = 0x011a;
+pub const _EXIF_TAG_Y_RESOLUTION: u16 = 0x011b;
+pub const _EXIF_TAG_PLANAR_CONFIGURATION: u16 = 0x011c;
+pub const _EXIF_TAG_RESOLUTION_UNIT: u16 = 0x0128;
+pub const _EXIF_TAG_TRANSFER_FUNCTION: u16 = 0x012d;
+pub const _EXIF_TAG_SOFTWARE: u16 = 0x0131;
+pub const _EXIF_TAG_DATE_TIME: u16 = 0x0132;
+pub const _EXIF_TAG_ARTIST: u16 = 0x013b;
+pub const _EXIF_TAG_WHITE_POINT: u16 = 0x013e;
+pub const _EXIF_TAG_PRIMARY_CHROMATICITIES: u16 = 0x013f;
 pub const TIFF_TAG_TILE_WIDTH: u16 = 0x0142;
 pub const TIFF_TAG_TILE_LENGTH: u16 = 0x0143;
 pub const TIFF_TAG_TILE_OFFSETS: u16 = 0x0144;
 pub const TIFF_TAG_TILE_BYTECOUNTS: u16 = 0x0145;
-pub const EXIF_TAG_TRANSFER_RANGE: u16 = 0x0156;
+pub const _EXIF_TAG_TRANSFER_RANGE: u16 = 0x0156;
 pub const EXIF_TAG_SUB_IFDS: u16 = 0x014a;
-pub const EXIF_TAG_JPEG_PROC: u16 = 0x0200;
+pub const _EXIF_TAG_JPEG_PROC: u16 = 0x0200;
 pub const EXIF_TAG_JPEG_INTERCHANGE_FORMAT: u16 = 0x0201;
 pub const EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH: u16 = 0x0202;
-pub const EXIF_TAG_YCBCR_COEFFICIENTS: u16 = 0x0211;
-pub const EXIF_TAG_YCBCR_SUB_SAMPLING: u16 = 0x0212;
-pub const EXIF_TAG_YCBCR_POSITIONING: u16 = 0x0213;
-pub const EXIF_TAG_REFERENCE_BLACK_WHITE: u16 = 0x0214;
-pub const EXIF_TAG_XML_PACKET: u16 = 0x02bc;
-pub const EXIF_TAG_RELATED_IMAGE_FILE_FORMAT: u16 = 0x1000;
-pub const EXIF_TAG_RELATED_IMAGE_WIDTH: u16 = 0x1001;
-pub const EXIF_TAG_RELATED_IMAGE_LENGTH: u16 = 0x1002;
-pub const EXIF_TAG_CFA_REPEAT_PATTERN_DIM: u16 = 0x828d;
+pub const _EXIF_TAG_YCBCR_COEFFICIENTS: u16 = 0x0211;
+pub const _EXIF_TAG_YCBCR_SUB_SAMPLING: u16 = 0x0212;
+pub const _EXIF_TAG_YCBCR_POSITIONING: u16 = 0x0213;
+pub const _EXIF_TAG_REFERENCE_BLACK_WHITE: u16 = 0x0214;
+pub const _EXIF_TAG_XML_PACKET: u16 = 0x02bc;
+pub const _EXIF_TAG_RELATED_IMAGE_FILE_FORMAT: u16 = 0x1000;
+pub const _EXIF_TAG_RELATED_IMAGE_WIDTH: u16 = 0x1001;
+pub const _EXIF_TAG_RELATED_IMAGE_LENGTH: u16 = 0x1002;
+pub const _EXIF_TAG_CFA_REPEAT_PATTERN_DIM: u16 = 0x828d;
 pub const EXIF_TAG_CFA_PATTERN: u16 = 0x828e;
-pub const EXIF_TAG_BATTERY_LEVEL: u16 = 0x828f;
-pub const EXIF_TAG_COPYRIGHT: u16 = 0x8298;
-pub const EXIF_TAG_EXPOSURE_TIME: u16 = 0x829a;
-pub const EXIF_TAG_FNUMBER: u16 = 0x829d;
-pub const EXIF_TAG_IPTC_NAA: u16 = 0x83bb;
-pub const EXIF_TAG_IMAGE_RESOURCES: u16 = 0x8649;
+pub const _EXIF_TAG_BATTERY_LEVEL: u16 = 0x828f;
+pub const _EXIF_TAG_COPYRIGHT: u16 = 0x8298;
+pub const _EXIF_TAG_EXPOSURE_TIME: u16 = 0x829a;
+pub const _EXIF_TAG_FNUMBER: u16 = 0x829d;
+pub const _EXIF_TAG_IPTC_NAA: u16 = 0x83bb;
+pub const _EXIF_TAG_IMAGE_RESOURCES: u16 = 0x8649;
 pub const EXIF_TAG_EXIF_IFD_POINTER: u16 = 0x8769;
-pub const EXIF_TAG_INTER_COLOR_PROFILE: u16 = 0x8773;
-pub const EXIF_TAG_EXPOSURE_PROGRAM: u16 = 0x8822;
-pub const EXIF_TAG_SPECTRAL_SENSITIVITY: u16 = 0x8824;
-pub const EXIF_TAG_GPS_INFO_IFD_POINTER: u16 = 0x8825;
-pub const EXIF_TAG_ISO_SPEED_RATINGS: u16 = 0x8827;
-pub const EXIF_TAG_OECF: u16 = 0x8828;
-pub const EXIF_TAG_EXIF_VERSION: u16 = 0x9000;
+pub const _EXIF_TAG_INTER_COLOR_PROFILE: u16 = 0x8773;
+pub const _EXIF_TAG_EXPOSURE_PROGRAM: u16 = 0x8822;
+pub const _EXIF_TAG_SPECTRAL_SENSITIVITY: u16 = 0x8824;
+pub const _EXIF_TAG_GPS_INFO_IFD_POINTER: u16 = 0x8825;
+pub const _EXIF_TAG_ISO_SPEED_RATINGS: u16 = 0x8827;
+pub const _EXIF_TAG_OECF: u16 = 0x8828;
+pub const _EXIF_TAG_EXIF_VERSION: u16 = 0x9000;
 pub const EXIF_TAG_DATE_TIME_ORIGINAL: u16 = 0x9003;
 pub const EXIF_TAG_DATE_TIME_DIGITIZED: u16 = 0x9004;
-pub const EXIF_TAG_COMPONENTS_CONFIGURATION: u16 = 0x9101;
-pub const EXIF_TAG_COMPRESSED_BITS_PER_PIXEL: u16 = 0x9102;
-pub const EXIF_TAG_SHUTTER_SPEED_VALUE: u16 = 0x9201;
-pub const EXIF_TAG_APERTURE_VALUE: u16 = 0x9202;
-pub const EXIF_TAG_BRIGHTNESS_VALUE: u16 = 0x9203;
-pub const EXIF_TAG_EXPOSURE_BIAS_VALUE: u16 = 0x9204;
-pub const EXIF_TAG_MAX_APERTURE_VALUE: u16 = 0x9205;
+pub const _EXIF_TAG_COMPONENTS_CONFIGURATION: u16 = 0x9101;
+pub const _EXIF_TAG_COMPRESSED_BITS_PER_PIXEL: u16 = 0x9102;
+pub const _EXIF_TAG_SHUTTER_SPEED_VALUE: u16 = 0x9201;
+pub const _EXIF_TAG_APERTURE_VALUE: u16 = 0x9202;
+pub const _EXIF_TAG_BRIGHTNESS_VALUE: u16 = 0x9203;
+pub const _EXIF_TAG_EXPOSURE_BIAS_VALUE: u16 = 0x9204;
+pub const _EXIF_TAG_MAX_APERTURE_VALUE: u16 = 0x9205;
 pub const EXIF_TAG_SUBJECT_DISTANCE: u16 = 0x9206;
 pub const EXIF_TAG_METERING_MODE: u16 = 0x9207;
-pub const EXIF_TAG_LIGHT_SOURCE: u16 = 0x9208;
+pub const _EXIF_TAG_LIGHT_SOURCE: u16 = 0x9208;
 pub const EXIF_TAG_FLASH: u16 = 0x9209;
 pub const EXIF_TAG_FOCAL_LENGTH: u16 = 0x920a;
-pub const EXIF_TAG_SUBJECT_AREA: u16 = 0x9214;
-pub const EXIF_TAG_TIFF_EP_STANDARD_ID: u16 = 0x9216;
+pub const _EXIF_TAG_SUBJECT_AREA: u16 = 0x9214;
+pub const _EXIF_TAG_TIFF_EP_STANDARD_ID: u16 = 0x9216;
 pub const EXIF_TAG_MAKER_NOTE: u16 = 0x927c;
-pub const EXIF_TAG_USER_COMMENT: u16 = 0x9286;
-pub const EXIF_TAG_SUB_SEC_TIME: u16 = 0x9290;
-pub const EXIF_TAG_SUB_SEC_TIME_ORIGINAL: u16 = 0x9291;
-pub const EXIF_TAG_SUB_SEC_TIME_DIGITIZED: u16 = 0x9292;
-pub const EXIF_TAG_FLASH_PIX_VERSION: u16 = 0xa000;
-pub const EXIF_TAG_COLOR_SPACE: u16 = 0xa001;
+pub const _EXIF_TAG_USER_COMMENT: u16 = 0x9286;
+pub const _EXIF_TAG_SUB_SEC_TIME: u16 = 0x9290;
+pub const _EXIF_TAG_SUB_SEC_TIME_ORIGINAL: u16 = 0x9291;
+pub const _EXIF_TAG_SUB_SEC_TIME_DIGITIZED: u16 = 0x9292;
+pub const _EXIF_TAG_FLASH_PIX_VERSION: u16 = 0xa000;
+pub const _EXIF_TAG_COLOR_SPACE: u16 = 0xa001;
 pub const EXIF_TAG_PIXEL_X_DIMENSION: u16 = 0xa002;
 pub const EXIF_TAG_PIXEL_Y_DIMENSION: u16 = 0xa003;
-pub const EXIF_TAG_RELATED_SOUND_FILE: u16 = 0xa004;
-pub const EXIF_TAG_INTEROPERABILITY_IFD_POINTER: u16 = 0xa005;
-pub const EXIF_TAG_FLASH_ENERGY: u16 = 0xa20b;
-pub const EXIF_TAG_SPATIAL_FREQUENCY_RESPONSE: u16 = 0xa20c;
-pub const EXIF_TAG_FOCAL_PLANE_X_RESOLUTION: u16 = 0xa20e;
-pub const EXIF_TAG_FOCAL_PLANE_Y_RESOLUTION: u16 = 0xa20f;
-pub const EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT: u16 = 0xa210;
-pub const EXIF_TAG_SUBJECT_LOCATION: u16 = 0xa214;
-pub const EXIF_TAG_EXPOSURE_INDEX: u16 = 0xa215;
-pub const EXIF_TAG_SENSING_METHOD: u16 = 0xa217;
-pub const EXIF_TAG_FILE_SOURCE: u16 = 0xa300;
-pub const EXIF_TAG_SCENE_TYPE: u16 = 0xa301;
+pub const _EXIF_TAG_RELATED_SOUND_FILE: u16 = 0xa004;
+pub const _EXIF_TAG_INTEROPERABILITY_IFD_POINTER: u16 = 0xa005;
+pub const _EXIF_TAG_FLASH_ENERGY: u16 = 0xa20b;
+pub const _EXIF_TAG_SPATIAL_FREQUENCY_RESPONSE: u16 = 0xa20c;
+pub const _EXIF_TAG_FOCAL_PLANE_X_RESOLUTION: u16 = 0xa20e;
+pub const _EXIF_TAG_FOCAL_PLANE_Y_RESOLUTION: u16 = 0xa20f;
+pub const _EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT: u16 = 0xa210;
+pub const _EXIF_TAG_SUBJECT_LOCATION: u16 = 0xa214;
+pub const _EXIF_TAG_EXPOSURE_INDEX: u16 = 0xa215;
+pub const _EXIF_TAG_SENSING_METHOD: u16 = 0xa217;
+pub const _EXIF_TAG_FILE_SOURCE: u16 = 0xa300;
+pub const _EXIF_TAG_SCENE_TYPE: u16 = 0xa301;
 pub const EXIF_TAG_NEW_CFA_PATTERN: u16 = 0xa302;
-pub const EXIF_TAG_CUSTOM_RENDERED: u16 = 0xa401;
-pub const EXIF_TAG_EXPOSURE_MODE: u16 = 0xa402;
-pub const EXIF_TAG_WHITE_BALANCE: u16 = 0xa403;
-pub const EXIF_TAG_DIGITAL_ZOOM_RATIO: u16 = 0xa404;
-pub const EXIF_TAG_FOCAL_LENGTH_IN_35MM_FILM: u16 = 0xa405;
-pub const EXIF_TAG_SCENE_CAPTURE_TYPE: u16 = 0xa406;
-pub const EXIF_TAG_GAIN_CONTROL: u16 = 0xa407;
-pub const EXIF_TAG_CONTRAST: u16 = 0xa408;
-pub const EXIF_TAG_SATURATION: u16 = 0xa409;
-pub const EXIF_TAG_SHARPNESS: u16 = 0xa40a;
-pub const EXIF_TAG_DEVICE_SETTING_DESCRIPTION: u16 = 0xa40b;
-pub const EXIF_TAG_SUBJECT_DISTANCE_RANGE: u16 = 0xa40c;
-pub const EXIF_TAG_IMAGE_UNIQUE_ID: u16 = 0xa420;
+pub const _EXIF_TAG_CUSTOM_RENDERED: u16 = 0xa401;
+pub const _EXIF_TAG_EXPOSURE_MODE: u16 = 0xa402;
+pub const _EXIF_TAG_WHITE_BALANCE: u16 = 0xa403;
+pub const _EXIF_TAG_DIGITAL_ZOOM_RATIO: u16 = 0xa404;
+pub const _EXIF_TAG_FOCAL_LENGTH_IN_35MM_FILM: u16 = 0xa405;
+pub const _EXIF_TAG_SCENE_CAPTURE_TYPE: u16 = 0xa406;
+pub const _EXIF_TAG_GAIN_CONTROL: u16 = 0xa407;
+pub const _EXIF_TAG_CONTRAST: u16 = 0xa408;
+pub const _EXIF_TAG_SATURATION: u16 = 0xa409;
+pub const _EXIF_TAG_SHARPNESS: u16 = 0xa40a;
+pub const _EXIF_TAG_DEVICE_SETTING_DESCRIPTION: u16 = 0xa40b;
+pub const _EXIF_TAG_SUBJECT_DISTANCE_RANGE: u16 = 0xa40c;
+pub const _EXIF_TAG_IMAGE_UNIQUE_ID: u16 = 0xa420;
 pub const EXIF_TAG_CAMERA_OWNER_NAME: u16 = 0xa430;
 pub const EXIF_TAG_BODY_SERIAL_NUMBER: u16 = 0xa431;
-pub const EXIF_TAG_BODY_LENS_MAKE: u16 = 0xa433;
-pub const EXIF_TAG_BODY_LENS_MODEL: u16 = 0xa434;
-pub const EXIF_TAG_GAMMA: u16 = 0xa500;
-pub const EXIF_TAG_PRINT_IM: u16 = 0xc4a5;
+pub const _EXIF_TAG_BODY_LENS_MAKE: u16 = 0xa433;
+pub const _EXIF_TAG_BODY_LENS_MODEL: u16 = 0xa434;
+pub const _EXIF_TAG_GAMMA: u16 = 0xa500;
+pub const _EXIF_TAG_PRINT_IM: u16 = 0xc4a5;
 /* DNG tags */
 pub const TIFF_TAG_DNG_VERSION: u16 = 0xc612;
 pub const DNG_TAG_UNIQUE_CAMERA_MODEL: u16 = 0xc614;
 pub const DNG_TAG_LINEARIZATION_TABLE: u16 = 0xc618;
 pub const DNG_TAG_BLACK_LEVEL: u16 = 0xc61a;
 pub const DNG_TAG_WHITE_LEVEL: u16 = 0xc61d;
-pub const DNG_TAG_DEFAULT_CROP_ORIGIN: u16 = 0xc61f;
-pub const DNG_TAG_DEFAULT_CROP_SIZE: u16 = 0xc620;
+pub const _DNG_TAG_DEFAULT_CROP_ORIGIN: u16 = 0xc61f;
+pub const _DNG_TAG_DEFAULT_CROP_SIZE: u16 = 0xc620;
 pub const DNG_TAG_COLORMATRIX1: u16 = 0xc621;
 pub const DNG_TAG_COLORMATRIX2: u16 = 0xc622;
-pub const DNG_TAG_CAMERA_CALIBRATION1: u16 = 0xc623;
-pub const DNG_TAG_CAMERA_CALIBRATION2: u16 = 0xc624;
-pub const DNG_TAG_REDUCTION_MATRIX1: u16 = 0xc625;
-pub const DNG_TAG_REDUCTION_MATRIX2: u16 = 0xc626;
-pub const DNG_TAG_ANALOG_BALANCE: u16 = 0xc627;
+pub const _DNG_TAG_CAMERA_CALIBRATION1: u16 = 0xc623;
+pub const _DNG_TAG_CAMERA_CALIBRATION2: u16 = 0xc624;
+pub const _DNG_TAG_REDUCTION_MATRIX1: u16 = 0xc625;
+pub const _DNG_TAG_REDUCTION_MATRIX2: u16 = 0xc626;
+pub const _DNG_TAG_ANALOG_BALANCE: u16 = 0xc627;
 pub const DNG_TAG_AS_SHOT_NEUTRAL: u16 = 0xc628;
-pub const DNG_TAG_AS_SHOT_WHITE_XY: u16 = 0xc629;
-pub const DNG_TAG_DNG_PRIVATE: u16 = 0xc634;
+pub const _DNG_TAG_AS_SHOT_WHITE_XY: u16 = 0xc629;
+pub const _DNG_TAG_DNG_PRIVATE: u16 = 0xc634;
 pub const DNG_TAG_CALIBRATION_ILLUMINANT1: u16 = 0xc65a;
 pub const DNG_TAG_CALIBRATION_ILLUMINANT2: u16 = 0xc65b;
-pub const DNG_TAG_ORIGINAL_RAW_FILE_NAME: u16 = 0xc68b;
+pub const _DNG_TAG_ORIGINAL_RAW_FILE_NAME: u16 = 0xc68b;
 pub const DNG_TAG_ACTIVE_AREA: u16 = 0xc68d;
 
 /* ARW tags */
@@ -191,9 +193,9 @@ pub const ORF_TAG_RAW_DEVELOPMENT2: u16 = 0x2031;
 /// Image processing IFD
 pub const ORF_TAG_IMAGE_PROCESSING: u16 = 0x2040;
 pub const ORF_TAG_IP_WHITE_BALANCE_RB: u16 = 0x0100;
-pub const ORF_TAG_IP_WHITE_BALANCE_G: u16 = 0x011f;
-pub const ORF_TAG_IP_COLOR_MATRIX: u16 = 0x200;
-pub const ORF_TAG_IP_BLACK_LEVEL: u16 = 0x0600;
+pub const _ORF_TAG_IP_WHITE_BALANCE_G: u16 = 0x011f;
+pub const _ORF_TAG_IP_COLOR_MATRIX: u16 = 0x200;
+pub const _ORF_TAG_IP_BLACK_LEVEL: u16 = 0x0600;
 pub const ORF_TAG_IP_CROP_LEFT: u16 = 0x0612;
 pub const ORF_TAG_IP_CROP_TOP: u16 = 0x0613;
 pub const ORF_TAG_IP_CROP_WIDTH: u16 = 0x0614;
@@ -205,12 +207,12 @@ pub const ORF_TAG_RAW_INFO: u16 = 0x3000;
 
 /* CR2 tags */
 /// This tag is present in the RAW IFD for Canon CR2.
-pub const CR2_TAG_C5D8: u16 = 0xc5d8;
-pub const CR2_TAG_C5D9: u16 = 0xc5d9;
+pub const _CR2_TAG_C5D8: u16 = 0xc5d8;
+pub const _CR2_TAG_C5D9: u16 = 0xc5d9;
 /// Exif tag for CR2 RAW "slices"
 pub const CR2_TAG_SLICE: u16 = 0xc640;
-pub const CR2_TAG_SRAW_TYPE: u16 = 0xc6c5;
-pub const CR2_TAG_C6D6: u16 = 0xc6d6;
+pub const _CR2_TAG_SRAW_TYPE: u16 = 0xc6c5;
+pub const _CR2_TAG_C6D6: u16 = 0xc6d6;
 
 /* RW2 tags */
 pub const RW2_TAG_SENSOR_WIDTH: u16 = 0x0002;
@@ -227,20 +229,20 @@ pub const RW2_TAG_LINEARITY_LIMIT_GREEN: u16 = 0x00f;
 pub const RW2_TAG_LINEARITY_LIMIT_BLUE: u16 = 0x010;
 pub const RW2_TAG_RED_BALANCE: u16 = 0x011;
 pub const RW2_TAG_BLUE_BALANCE: u16 = 0x012;
-pub const RW2_TAG_WB_INFO: u16 = 0x013;
+pub const _RW2_TAG_WB_INFO: u16 = 0x013;
 pub const RW2_TAG_BLACK_LEVEL_RED: u16 = 0x01c;
 pub const RW2_TAG_BLACK_LEVEL_GREEN: u16 = 0x01d;
 pub const RW2_TAG_BLACK_LEVEL_BLUE: u16 = 0x01e;
 pub const RW2_TAG_WB_RED_LEVEL: u16 = 0x024;
 pub const RW2_TAG_WB_GREEN_LEVEL: u16 = 0x025;
 pub const RW2_TAG_WB_BLUE_LEVEL: u16 = 0x026;
-pub const RW2_TAG_IMAGE_RAWFORMAT: u16 = 0x002d;
+pub const _RW2_TAG_IMAGE_RAWFORMAT: u16 = 0x002d;
 pub const RW2_TAG_JPEG_FROM_RAW: u16 = 0x002e;
 pub const RW2_TAG_RAW_OFFSET: u16 = 0x0118;
 pub const RW2_TAG_CAMERA_IFD: u16 = 0x0120;
 
 /* Pentax MakerNote tags */
-pub const MNOTE_PENTAX_PREVIEW_IMAGE_SIZE: u16 = 0x02;
+pub const _MNOTE_PENTAX_PREVIEW_IMAGE_SIZE: u16 = 0x02;
 pub const MNOTE_PENTAX_PREVIEW_IMAGE_LENGTH: u16 = 0x03;
 pub const MNOTE_PENTAX_PREVIEW_IMAGE_START: u16 = 0x04;
 pub const MNOTE_PENTAX_MODEL_ID: u16 = 0x05;
@@ -254,8 +256,8 @@ pub const MNOTE_PENTAX_WHITE_BALANCE: u16 = 0x201;
 /* Canon MakerNote tags */
 /// The model ID for Canon cameras.
 pub const MNOTE_CANON_MODEL_ID: u16 = 0x0010;
-pub const MNOTE_CANON_RAW_DATA_OFFSET: u16 = 0x0081;
-pub const MNOTE_CANON_RAW_DATA_LENGTH: u16 = 0x0082;
+pub const _MNOTE_CANON_RAW_DATA_OFFSET: u16 = 0x0081;
+pub const _MNOTE_CANON_RAW_DATA_LENGTH: u16 = 0x0082;
 pub const MNOTE_CANON_SENSORINFO: u16 = 0x00e0;
 pub const MNOTE_CANON_COLOR_DATA: u16 = 0x4001;
 
@@ -267,8 +269,8 @@ pub const MNOTE_NIKON_QUALITY: u16 = 0x04;
 pub const MNOTE_NIKON_WB_RB_LEVELS: u16 = 0x0c;
 pub const MNOTE_NIKON_PREVIEW_IFD: u16 = 0x11;
 pub const MNOTE_NIKON_COLOR_BALANCE_A: u16 = 0x14;
-pub const MNOTE_NIKON_SERIAL_NUMBER: u16 = 0x1d;
-pub const MNOTE_NIKON_SHUTTER_COUNT: u16 = 0xa7;
+pub const _MNOTE_NIKON_SERIAL_NUMBER: u16 = 0x1d;
+pub const _MNOTE_NIKON_SHUTTER_COUNT: u16 = 0xa7;
 pub const MNOTE_NIKON_NEFDECODETABLE2: u16 = 0x96;
 pub const MNOTE_NIKON_COLOR_BALANCE: u16 = 0x97;