Squashed 'third_party/apriltag/' content from commit 3e8e974d0

git-subtree-dir: third_party/apriltag
git-subtree-split: 3e8e974d0d8d6ab318abf56d87506d15d7f2cc35
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
Change-Id: I04ba3cb2106b6813a1013d57aa8074c26f856598
diff --git a/common/pjpeg.h b/common/pjpeg.h
new file mode 100644
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--- /dev/null
+++ b/common/pjpeg.h
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+/* Copyright (C) 2013-2016, The Regents of The University of Michigan.
+All rights reserved.
+This software was developed in the APRIL Robotics Lab under the
+direction of Edwin Olson, ebolson@umich.edu. This software may be
+available under alternative licensing terms; contact the address above.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+The views and conclusions contained in the software and documentation are those
+of the authors and should not be interpreted as representing official policies,
+either expressed or implied, of the Regents of The University of Michigan.
+*/
+
+#pragma once
+
+#include "image_u8.h"
+#include "image_u8x3.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct pjpeg_component pjpeg_component_t;
+struct pjpeg_component
+{
+    // resolution of this component (which is smaller than the
+    // dimensions of the image if the channel has been sub-sampled.)
+    uint32_t width, height;
+
+    // number of bytes per row. May be larger than width for alignment
+    // reasons.
+    uint32_t stride;
+
+    // data[y*stride + x]
+    uint8_t *data;
+
+    ////////////////////////////////////////////////////////////////
+    // These items probably not of great interest to most
+    // applications.
+    uint8_t id; // the identifier associated with this component
+    uint8_t hv; // horiz scale (high 4 bits) / vert scale (low 4 bits)
+    uint8_t scalex, scaley; // derived from hv above
+    uint8_t tq; // quantization table index
+
+    // this filled in at the last moment by SOS
+    uint8_t tda; // which huff tables will we use for DC (high 4 bits) and AC (low 4 bits)
+};
+
+typedef struct pjpeg pjpeg_t;
+struct pjpeg
+{
+    // status of the decode is put here. Non-zero means error.
+    int error;
+
+    uint32_t width, height; // pixel dimensions
+
+    int ncomponents;
+    pjpeg_component_t *components;
+};
+
+enum PJPEG_FLAGS {
+    PJPEG_STRICT = 1,  // Don't try to recover from errors.
+    PJPEG_MJPEG = 2,   // Support JPGs with missing DHT segments.
+};
+
+enum PJPEG_ERROR {
+    PJPEG_OKAY = 0,
+    PJPEG_ERR_FILE, // something wrong reading file
+    PJPEG_ERR_DQT, // something wrong with DQT marker
+    PJPEG_ERR_SOF, // something wrong with SOF marker
+    PJPEG_ERR_DHT, // something wrong with DHT marker
+    PJPEG_ERR_SOS, // something wrong with SOS marker
+    PJPEG_ERR_MISSING_DHT, // missing a necessary huffman table
+    PJPEG_ERR_DRI, // something wrong with DRI marker
+    PJPEG_ERR_RESET, // didn't get a reset marker where we expected. Corruption?
+    PJPEG_ERR_EOF, // ran out of bytes while decoding
+    PJEPG_ERR_UNSUPPORTED, // an unsupported format
+};
+
+pjpeg_t *pjpeg_create_from_file(const char *path, uint32_t flags, int *error);
+pjpeg_t *pjpeg_create_from_buffer(uint8_t *buf, int buflen, uint32_t flags, int *error);
+void pjpeg_destroy(pjpeg_t *pj);
+
+image_u8_t *pjpeg_to_u8_baseline(pjpeg_t *pj);
+image_u8x3_t *pjpeg_to_u8x3_baseline(pjpeg_t *pj);
+
+#ifdef __cplusplus
+}
+#endif