From 28921c09ab8ad59e7f6997f98c1870e0f3f121a5 Mon Sep 17 00:00:00 2001 From: Zach Beane Date: Tue, 8 Sep 2009 13:17:18 -0400 Subject: [PATCH] Initial checkin for zpb-exif --- ChangeLog | 4 + exif.lisp | 1079 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ zpb-exif.asd | 42 +++ zpb-exif.html | 594 +++++++++++++++++++++++++++++++ 4 files changed, 1719 insertions(+) create mode 100644 ChangeLog create mode 100644 exif.lisp create mode 100644 zpb-exif.asd create mode 100644 zpb-exif.html diff --git a/ChangeLog b/ChangeLog new file mode 100644 index 0000000..ac7e294 --- /dev/null +++ b/ChangeLog @@ -0,0 +1,4 @@ +2005-12-15 Zach Beane + + * Made 1.0 release + diff --git a/exif.lisp b/exif.lisp new file mode 100644 index 0000000..9091291 --- /dev/null +++ b/exif.lisp @@ -0,0 +1,1079 @@ +;;; +;;; exif.lisp +;;; +;;; Created: 2005-12-08 by Zach Beane +;;; +;;; Copyright (c) 2005 Zachary Beane, All Rights Reserved +;;; +;;; Redistribution and use in source and binary forms, with or without +;;; modification, are permitted provided that the following conditions +;;; are met: +;;; +;;; * Redistributions of source code must retain the above copyright +;;; notice, this list of conditions and the following disclaimer. +;;; +;;; * 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 AUTHOR 'AS IS' AND ANY EXPRESSED +;;; 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 AUTHOR 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. +;;; +;;; $Id: exif.lisp,v 1.7 2009/09/08 17:14:22 xach Exp $ + +(defpackage :zpb-exif + (:use :cl) + (:export :make-exif + ;; IFDs + :image-ifd + :thumbnail-ifd + :exif-ifd + :gps-ifd + :interoperability-ifd + ;; Pulling values from IFDs and entries + :ifd-entry + :entry-value + :parsed-entry-value + ;; Convenience + :exif-value + :parsed-exif-value + :parse-exif-data + :exif-data + :thumbnail-image + :ifd-alist + :exif-alist + ;; Conditions + :invalid-stream + :invalid-jpeg-stream + :invalid-exif-stream) + (:shadow count type)) + +(in-package :zpb-exif) + + +;;; Conditions + +(define-condition invalid-stream (error) ()) + +(define-condition invalid-jpeg-stream (invalid-stream) ()) + +(define-condition invalid-exif-stream (invalid-stream) ()) + +(eval-when (:compile-toplevel :load-toplevel :execute) + (defparameter *optimizations* + '(optimize (speed 3) (safety 0))) + + (defparameter *optimizations* '(optimize))) + + +;;; Fetching data + +(defun get-32/lsb (pos buf) + (declare (cl:type (simple-array (unsigned-byte 8) (*)) buf) + (fixnum pos) + #.*optimizations*) + (logand #xFFFFFFFF + (+ (ash (aref buf pos) 0) + (ash (aref buf (incf pos)) 8) + (ash (aref buf (incf pos)) 16) + (ash (aref buf (incf pos)) 24)))) + +(defun get-32/msb (pos buf) + (declare (cl:type (simple-array (unsigned-byte 8) (*)) buf) + (fixnum pos) + #.*optimizations*) + (logand #xFFFFFFFF + (+ (ash (aref buf pos) 24) + (ash (aref buf (incf pos)) 16) + (ash (aref buf (incf pos)) 8) + (ash (aref buf (incf pos)) 0)))) + +(defun get-16/lsb (pos buf) + (declare (cl:type (simple-array (unsigned-byte 8) (*)) buf) + (fixnum pos) + #.*optimizations*) + (logand #xFFFF + (+ (ash (aref buf pos) 0) + (ash (aref buf (incf pos)) 8)))) + +(defun get-16/msb (pos buf) + (declare (cl:type (simple-array (unsigned-byte 8) (*)) buf) + (fixnum pos) + #.*optimizations*) + (logand #xFFFF + (+ (ash (aref buf pos) 8) + (ash (aref buf (incf pos)) 0)))) + +(defun get-8/* (pos buf) + (declare (cl:type (simple-array (unsigned-byte 8) (*)) buf) + (fixnum pos) + #.*optimizations*) + (logand #xFF (aref buf pos))) + + +;;; The exif object + +(defclass exif () + ((file + :initarg :file + :initform nil + :reader file) + (data + :initarg :data + :reader data) + (offset + :initarg :offset + :reader offset + :documentation + "The position in the input stream from where the Exif data was read.") + (get-32-function + :initarg :get-32-function + :reader get-32-function) + (get-16-function + :initarg :get-16-function + :reader get-16-function) + (endianness + :initarg :endianness + :reader endianness) + (image-ifd + :initarg :image-ifd + :initform nil + :accessor image-ifd) + (thumbnail-ifd + :initarg :thumbnail-ifd + :initform nil + :accessor thumbnail-ifd) + (exif-ifd + :initarg :exif-ifd + :initform nil + :accessor exif-ifd) + (gps-ifd + :initarg :gps-ifd + :initform nil + :accessor gps-ifd) + (interoperability-ifd + :initarg :interoperability-ifd + :initform nil + :accessor interoperability-ifd))) + +(defun exif-data (exif) + (data exif)) + +(defun get-8 (pos exif) + (get-8/* pos (data exif))) + +(defun get-16 (pos exif) + (funcall (get-16-function exif) pos (data exif))) + +(defun get-32 (pos exif) + (funcall (get-32-function exif) pos (data exif))) + +(defun get-string (pos length exif) + (let ((data (data exif)) + (string (make-string (1- length)))) + (loop for i from pos + for j from 0 + repeat (1- length) + do (setf (char string j) (code-char (aref data i)))) + string)) + + +;;; Reading the various data types + +(defun long->slong (long) + (if (logbitp 31 long) + (dpb long (byte 32 0) -1) + long)) + +(defmacro do-gets ((j start step count) &body body) + "Evaluate BODY COUNT times, binding J to START initially, then +incrementing it by STEP. The results of the evaluation are returned as +a vector." + (let ((result (gensym)) + (i (gensym))) + `(do ((,result (make-array ,count)) + (,i 0 (1+ ,i )) + (,j ,start (+ ,j ,step))) + ((= ,i ,count) ,result) + (setf (aref ,result ,i) + ,@body)))) + +(defun get-byte (type count pos exif) + (declare (ignore type)) + (if (= count 1) + (get-8 pos exif) + (subseq (data exif) pos (+ pos count)))) + +(defun get-ascii (type count pos exif) + (declare (ignore type)) + (get-string pos count exif)) + +(defun get-short (type count pos exif) + (declare (ignore type)) + (if (= count 1) + (get-16 pos exif) + (do-gets (i pos 2 count) + (get-16 i exif)))) + +(defun get-long (type count pos exif) + (declare (ignore type)) + (if (= count 1) + (get-32 pos exif) + (do-gets (i pos 4 count) + (get-32 i exif)))) + +(defun get-rational (type count pos exif) + (declare (ignore type)) + (if (= count 1) + (let ((numerator (get-32 pos exif)) + (denominator (get-32 (+ 4 pos ) exif))) + (if (zerop denominator) + 0 + (/ numerator denominator))) + (do-gets (i pos 8 count) + (let ((numerator (get-32 i exif)) + (denominator (get-32 (+ 4 i) exif))) + (if (zerop denominator) + 0 + (/ numerator denominator)))))) + +(defun get-undefined (type count pos exif) + (declare (ignore type)) + (subseq (data exif) pos (+ pos count))) + +(defun get-slong (type count pos exif) + (declare (ignore type)) + (if (= count 1) + (long->slong (get-32 pos exif)) + (do-gets (i pos 4 count) + (long->slong (get-32 i exif))))) + +(defun get-srational (type count pos exif) + (declare (ignore type)) + (if (= count 1) + (/ (long->slong (get-32 pos exif)) + (long->slong (get-32 (+ pos 4) exif))) + (do-gets (i pos 8 count) + (/ (long->slong (get-32 i exif)) + (long->slong (get-32 (+ i 4) exif)))))) + +(defun get-unknown-type (type &rest args) + (declare (ignore args)) + (warn "Encountered unknown data type ~D, ignoring" type) + nil) + +(defparameter *type-readers* + #(get-unknown-type ; 0 + get-byte ; 1 + get-ascii ; 2 + get-short ; 3 + get-long ; 4 + get-rational ; 5 + get-unknown-type ; 6 + get-undefined ; 7 + get-unknown-type ; 8 + get-slong ; 9 + get-srational ;10 + get-unknown-type ;11 + get-unknown-type ;12 + get-unknown-type ;13 + get-unknown-type ;14 + get-unknown-type ;15 + )) + + +;;; IFDs + +(defclass ifd () + ((tagset + :initarg :tagset + :accessor tagset) + (entries + :initarg :entries + :accessor entries) + (next-ifd-offset + :initarg :next-ifd-offset + :initform 0 + :accessor next-ifd-offset))) + +(defmethod print-object ((ifd ifd) stream) + (print-unreadable-object (ifd stream :type t :identity t) + (format stream "(~D entries)" (length (entries ifd))))) + +(defclass ifd-entry () + ((exif + :initarg :exif + :reader exif) + (ifd + :initarg :ifd + :reader ifd) + (tag + :initarg :tag + :reader tag) + (type + :initarg :type + :reader type) + (count + :initarg :count + :reader count) + (value-offset + :initarg :value-offset + :reader value-offset) + (value + :initarg :value + :reader %value + :writer (setf value)))) + +(defun immediate-value-p (type count) + "Can COUNT items of TYPE be stored in the 32-bit IFD entry value +offset area?" + (case type + ;; octet-sized types + ((1 2 7) (<= count 4)) + ;; 16-bit type + (3 (< count 2)) + ;; 32-bit types + ((4 9) (= count 1)))) + +(defun read-ifd-value (type count pos exif) + (funcall (aref *type-readers* type) type count pos exif)) + +(defun read-ifd-entry (pos ifd exif) + (let ((tag (get-16 pos exif)) + (type (get-16 (+ pos 2) exif)) + (count (get-32 (+ pos 4) exif)) + (value-offset (get-32 (+ pos 8) exif))) + (let ((ifd-entry (make-instance 'ifd-entry + :exif exif + :ifd ifd + :tag tag + :type type + :count count + :value-offset value-offset))) + (when (immediate-value-p type count) + (setf (value ifd-entry) (read-ifd-value type count (+ pos 8) exif))) + ifd-entry))) + +(defun read-ifd (pos tagset exif) + (let* ((entry-count (get-16 pos exif)) + (entries (make-array entry-count)) + (next-ifd-offset (get-32 (+ pos 2 (* 12 entry-count)) exif)) + (ifd (make-instance 'ifd + :tagset tagset + :entries entries + :next-ifd-offset next-ifd-offset))) + (loop for i below entry-count + for j from 2 by 12 + do (setf (aref entries i) (read-ifd-entry (+ pos j) ifd exif))) + ifd)) + +(defun initialize-ifd-entry (ifd-entry) + (with-slots (exif type count value-offset) + ifd-entry + (setf (value ifd-entry) (read-ifd-value type count value-offset exif)))) + +(defun entry-value (ifd-entry) + (when ifd-entry + (if (slot-boundp ifd-entry 'value) + (%value ifd-entry) + (initialize-ifd-entry ifd-entry)))) + +(defun bisect-find (object vector &key (key #'identity)) + (let ((lo 0) + (hi (length vector)) + (mid nil)) + (loop + (when (<= hi lo) + (return)) + (setf mid (ash (+ hi lo) -1)) + (let ((candidate (funcall key (aref vector mid)))) + (cond ((= candidate object) + (return (aref vector mid))) + ((< object candidate) + (setf hi mid)) + (t + (setf lo (1+ mid)))))))) + +(defun %ifd-entry (tag ifd) + (when ifd + (bisect-find tag (entries ifd) :key #'tag))) + + +;;; +;;; Initializing IFDs in the exif +;;; +;;; An IFD is a directory of tag/value structures. Exif defines +;;; separate IFD tags for image information, exif-specific +;;; information, GPS information, and interoperability +;;; information. There may be image, exif, and GPS IFDs for both the +;;; primary image and the thumbnail image. +;;; +;;; The image information IFD has pointers to exif and GPS IFDs. The +;;; exif IFD has a pointer to the interoperability IFD. +;;; +;;; FIXME: GPS and Exif IFDs for the thumbnail image are ignored. +;;; + +(defun initialize-exif-ifds (exif) + (let ((image-ifd-offset (get-32 4 exif))) + (with-slots (image-ifd thumbnail-ifd exif-ifd + gps-ifd interoperability-ifd) + exif + (setf image-ifd (read-ifd image-ifd-offset 'image exif)) + (unless (zerop (next-ifd-offset image-ifd)) + (setf thumbnail-ifd (read-ifd (next-ifd-offset image-ifd) + 'image + exif))) + (let ((exif-ifd-offset (entry-value (%ifd-entry #x8769 image-ifd))) + (gps-ifd-offset (entry-value (%ifd-entry #x8825 image-ifd)))) + (when exif-ifd-offset + (setf exif-ifd (read-ifd exif-ifd-offset 'exif exif)) + (let ((interoperability-ifd-offset (entry-value (%ifd-entry + #xA005 + exif-ifd)))) + (when interoperability-ifd-offset + (setf interoperability-ifd (read-ifd interoperability-ifd-offset + 'interoperability + exif))))) + (when gps-ifd-offset + (setf gps-ifd (read-ifd gps-ifd-offset 'gps exif))) + exif)))) + + + + +;;; Creating an exif object from a stream + +(defparameter *reader-functions/msb* + '(get-32/msb + get-16/msb)) + +(defparameter *reader-functions/lsb* + '(get-32/lsb + get-16/lsb)) + +(defun read-jpeg-uint16 (stream) + (logand #xFFFF + (+ (ash (read-byte stream) 8) + (read-byte stream)))) + +(defun check-bytes (stream &rest bytes) + "Return true if next bytes of STREAM match the list BYTES." + (loop for byte in bytes + always (= (read-byte stream) byte))) + +(defun seek-to-app1 (stream) + "Position STREAM after the #xFF, #xE1 marker in the JPEG stream +representing the APP1 segment. Raise an INVALID-EXIF-STREAM error if +no APP1 segment can be found." + (do ((first-byte (read-byte stream nil) next-byte) + (next-byte (read-byte stream nil) (read-byte stream nil))) + ((not (and first-byte next-byte))) + (cond ((and (= first-byte #xFF) (= next-byte #xE1)) + (return)) + ((and (= first-byte #xFF) (<= #xE0 next-byte #xEF)) + (let ((appn-size (read-jpeg-uint16 stream))) + (file-position stream (+ (file-position stream) + (- appn-size 2))))) + ((= next-byte #xFF) + ;; padding -- do nothing + ) + (t + (error 'invalid-exif-stream))))) + +(defun make-exif-from-stream (stream) + "Extract an Exif object from the open (unsigned-byte 8) STREAM. The +stream must be positioned at the beginning of JPEG data. If the stream +is not a JPEG stream, raise INVALID-JPEG-STREAM. If the stream does +not contain Exif data, raise INVALID-EXIF-STREAM." + (unless (check-bytes stream #xFF #xD8) + (error 'invalid-jpeg-stream)) + (seek-to-app1 stream) + (let ((size (read-jpeg-uint16 stream))) + ;; ASCII "Exif" + (unless (check-bytes stream #x45 #x78 #x69 #x66 #x00 #x00) + (error 'invalid-exif-stream)) + (let ((data (make-array size :element-type '(unsigned-byte 8))) + (offset (file-position stream))) + (read-sequence data stream) + ;; ASCII #\I or #\M + (let ((endianness (if (= (aref data 0) (aref data 1) #x49) + :lsb + :msb))) + (destructuring-bind (get-32 get-16) + (if (eql endianness :lsb) + *reader-functions/lsb* + *reader-functions/msb*) + (initialize-exif-ifds + (make-instance 'exif + :file (ignore-errors (truename stream)) + :data data + :offset offset + :endianness endianness + :get-32-function get-32 + :get-16-function get-16))))))) + +(defun make-exif-from-file (file) + (with-open-file (stream file + :direction :input + :element-type '(unsigned-byte 8)) + (make-exif-from-stream stream))) + +(defun make-exif (object) + "Read and create an exif object from OBJECT, which may be a pathname +designator or a stream." + (etypecase object + ((or string pathname) (make-exif-from-file object)) + (stream (make-exif-from-stream object)))) + + +;;; Tagsets +;;; +;;; This is necessary because, unfortunately, tags are only unique +;;; within a particular IFD. The GPS and interoperability IFDs, for +;;; example, have conflicting tags. + +(defclass tagset-entry () + ((tag + :initarg :tag + :reader tag) + (name + :initarg :name + :reader name) + (type + :initarg :type + :reader type))) + +(defun tag-name (code tagset) + (let ((table (get tagset 'tagset-code-table))) + (if table + (let ((entry (gethash code table))) + (when entry + (name entry))) + (error "~A is not a known tagset" tagset)))) + +(defun tag-type (code tagset) + (let ((table (get tagset 'tagset-code-table))) + (if table + (let ((entry (gethash code table))) + (when entry + (type entry))) + (error "~A is not a known tagset" tagset)))) + +(defun tag-code (name tagset) + (let ((table (get tagset 'tagset-name-table))) + (if table + (nth-value 0 (gethash name table)) + (error "~A is not a known tagset" tagset)))) + +(defmacro define-tagset (name &body tag-definitions) + (let ((name-table (gensym)) + (code-table (gensym)) + (setfs '())) + `(let ((,name-table (make-hash-table :test 'equalp)) + (,code-table (make-hash-table))) + (setf (get ',name 'tagset-name-table) ,name-table + (get ',name 'tagset-code-table) ,code-table) + ,@(dolist (definition tag-definitions setfs) + (destructuring-bind (&key tag name type) + definition + (push `(setf (gethash ,name ,name-table) ,tag + (gethash ,tag ,code-table) (make-instance 'tagset-entry + :tag ,tag + :name ,name + :type ',type)) + setfs)))))) + + +;;; Converting some Exif values to somewhat more parsed values + +(defun exif-type-parser-fun (exif-type) + (or (get exif-type 'exif-type-parser-fun) 'identity)) + +(defmacro define-exif-type (name (base-type) &rest options) + (declare (ignore base-type)) + (let ((forms + (loop for ((type . parameters)) on options + when (eql type :parser) + collect (destructuring-bind (lambda-list &body body) + parameters + `(setf (get ',name 'exif-type-parser-fun) + (lambda ,lambda-list ,@body)))))) + (when forms + `(progn ,@forms)))) + +(defun parse-datetime (string) + "Convert an Exif datetime string in the form \"YYYY:MM:DD hh:mm:ss\" +to a universal time." + ;; YYYY:MM:DD hh:mm:ss + ;; 0123456789012345678 + (flet ((integer-at (start end) + (parse-integer string :start start :end end))) + (encode-universal-time (integer-at 17 19) + (integer-at 14 16) + (integer-at 11 13) + (integer-at 8 10) + (integer-at 5 7) + (integer-at 0 4)))) + +;;; +;;; It was no fun to type all these in from JEITA CP-3451 +;;; + +;;; Generic types, used multiple times + +(define-exif-type datetime (ascii) + (:parser (value) + (parse-datetime value))) + +(define-exif-type floatable-rational (rational) + (:parser (value) + (float value))) + +;;; One-off types; used for a specific tag in a tagset + +(define-exif-type orientation (short) + (:parser (value) + (case value + (1 :normal) + (2 :flipped-horizontally) + (3 :rotated-180) + (4 :flipped-vertically) + (5 :rotated-270-and-flipped-horizontally) + (6 :rotated-270) + (7 :rotated-90-and-flipped-vertically) + (8 :rotated-90) + (otherwise :reserved)))) + +(define-exif-type exposure-program (short) + (:parser (value) + (case value + (0 :not-defined) + (1 :manual) + (2 :normal-program) + (3 :aperture-priority) + (4 :shutter-priority) + (5 :creative-program) + (6 :action-program) + (7 :portrait-mode) + (8 :landscape-mode) + (otherwise :reserved)))) + +(define-exif-type sensing-method (short) + (:parser (value) + (case value + (1 :not-defined) + (2 :one-chip-color-area-sensor) + (3 :two-chip-color-area-sensor) + (4 :three-chip-color-area-sensor) + (5 :color-sequential-area-sensor) + (6 :trilinear-sensor) + (7 :color-sequential-linear-sensor) + (otherwise :reserved)))) + +(define-exif-type metering-mode (short) + (:parser (value) + (case value + (0 :unknown) + (1 :average) + (2 :center-weighted-average) + (3 :spot) + (4 :multispot) + (5 :pattern) + (6 :partial) + (255 :other) + (otherwise :reserved)))) + +(define-exif-type light-source (short) + (:parser (value) + (case value + (0 :unknown) + (1 :daylight) + (2 :flourescent) + (3 :tungsten) + (4 :flash) + (9 :fine-weather) + (10 :cloudy-weather) + (11 :shade) + (12 :daylight-flourescent) + (13 :day-white-flourescent) + (14 :cool-white-flourescent) + (15 :white-flourescent) + (17 :standard-light-a) + (18 :standard-light-b) + (19 :standard-light-c) + (20 :d55) + (21 :d65) + (22 :d75) + (23 :d50) + (24 :iso-studio-tungsten) + (255 :other-light-source) + (otherwise :reserved)))) + +(define-exif-type flash (short) + (:parser (value) + ;; FIXME: a gross simplification + (logbitp 0 value))) + +(define-exif-type exposure-mode (short) + (:parser (value) + (case value + (0 :auto-exposure) + (1 :manual-exposure) + (2 :auto-bracket) + (otherwise :reserved)))) + +(define-exif-type white-balance (short) + (:parser (value) + (case value + (0 :auto) + (1 :manual) + (otherwise :reserved)))) + +(define-exif-type scene-capture-type (short) + (:parser (value) + (case value + (0 :standard) + (1 :landscape) + (2 :portrait) + (3 :night-scene) + (otherwise :reserved)))) + +(define-exif-type gain-control (short) + (:parser (value) + (case value + (0 :none) + (1 :low-gain-up) + (2 :high-gain-up) + (3 :low-gain-down) + (4 :high-gain-down) + (otherwise :reserved)))) + +(define-exif-type contrast (short) + (:parser (value) + (case value + (0 :normal) + (1 :soft) + (2 :hard) + (otherwise :reserved)))) + +(define-exif-type saturation (short) + (:parser (value) + (case value + (0 :normal) + (1 :low-saturation) + (2 :high-saturation) + (otherwise :reserved)))) + +(define-exif-type sharpness (short) + (:parser (value) + (case value + (0 :normal) + (1 :soft) + (2 :hard) + (otherwise :reserved)))) + +(define-exif-type subject-distance-range (short) + (:parser (value) + (case value + (0 :unknown) + (1 :macro) + (2 :close-view) + (3 :distant-view) + (otherwise :reserved)))) + +(define-exif-type exif-version (unknown) + (:parser (value) + ;; FIXME: ASCII-centric + (let ((version-string (make-array 5 :initial-element (char-code #\.)))) + (replace version-string value :start2 0 :end2 2) + (replace version-string value :start1 3 :start2 2) + (string-trim '(#\0) (map 'string #'code-char version-string))))) + +(define-exif-type color-space (short) + (:parser (value) + (case value + (1 :srgb) + (#xFFFF :uncalibrated) + (otherwise :reserved)))) + +(define-exif-type user-comment (undefined) + (:parser (value) + (flet ((starts-with (prefix) + (loop for i across prefix + for j across value + always (= i j)))) + (cond ((or (starts-with #(0 0 0 0 0 0 0 0)) + (starts-with #(#x41 #x53 #x43 #x49 #x49))) + ;; ASCII encoding + (let ((first-null (or (position 0 value :start 8) + (length value)))) + (map 'string #'code-char (subseq value 8 first-null)))) + (t value))))) + +(define-exif-type ycbcr-positioning (short) + (:parser (value) + (case value + (1 :centered) + (2 :co-sited) + (otherwise :reserved)))) + +(define-tagset image + ;; Tags relating to image data structure + (:tag #x0100 :name "ImageWidth" :type short/long) + (:tag #x0101 :name "ImageHeight" :type short/long) + (:tag #x0102 :name "BitsPerSample" :type short) + (:tag #x0103 :name "Compression" :type short) + (:tag #x0106 :name "PhotometricInterpretation" :type short) + (:tag #x0112 :name "Orientation" :type orientation) + (:tag #x0115 :name "SamplesPerPixel" :type short) + (:tag #x011C :name "PlanarConfiguration" :type short) + (:tag #x0212 :name "YCbCrSubSampling" :type short) + (:tag #x0213 :name "YCbCrPositioning" :type ycbcr-positioning) + (:tag #x011A :name "XResolution" :type rational) + (:tag #x011B :name "YResolution" :type rational) + (:tag #x0128 :name "ResolutionUnit" :type short) + ;; Tags relating to recording offset + (:tag #x0111 :name "StripOffsets" :type short/long) + (:tag #x0116 :name "RowsPerStrip" :type short/long) + (:tag #x0117 :name "StripByteCounts" :type short/long) + (:tag #x0201 :name "JPEGInterchangeFormat" :type long) + (:tag #x0202 :name "JPEGInterchangeFormatLength" :type long) + ;; Tags relating to image data characteristics + (:tag #x012D :name "TransferFunction" :type short) + (:tag #x013E :name "WhitePoint" :type rational) + (:tag #x013F :name "PrimaryChromaticities" :type rational) + (:tag #x0211 :name "YCbCrCoefficients" :type rational) + (:tag #x0214 :name "ReferenceBlackWhite" :type rational) + ;; Other tags + (:tag #x0132 :name "DateTime" :type datetime) + (:tag #x010E :name "ImageDescription" :type ascii) + (:tag #x010F :name "Make" :type ascii) + (:tag #x0110 :name "Model" :type ascii) + (:tag #x0131 :name "Software" :type ascii) + (:tag #x013B :name "Artist" :type ascii) + (:tag #x8298 :name "Copyright" :type ascii)) + +(define-tagset exif + ;; Tags Relating to Version + (:tag #x9000 :name "ExifVersion" :type exif-version) + (:tag #xA000 :name "FlashpixVersion" :type undefined) + ;; Tag Relating to Image Data Characteristics + (:tag #xA001 :name "ColorSpace" :type color-space) + (:tag #xA500 :name "Gamma" :type floatable-rational) + ;; Tags Relating to Image Configuration + (:tag #x9101 :name "ComponentsConfiguration" :type undefined) + (:tag #x9102 :name "CompressedBitsPerPixel" :type rational) + (:tag #xA002 :name "PixelXDimension" :type short/long) + (:tag #xA003 :name "PixelYDimension" :type short/long) + ;; Tags Relating to User Information + (:tag #x927C :name "MakerNote" :type undefined) + (:tag #x9286 :name "UserComment" :type user-comment) + ;; Tag Relating to Related File Information + (:tag #xA004 :name "RelatedSoundFile" :type ascii) + ;; Tags Relating to Date and Time + (:tag #x9003 :name "DateTimeOriginal" :type datetime) + (:tag #x9004 :name "DateTimeDigitized" :type datetime) + (:tag #x9290 :name "SubSecTime" :type ascii) + (:tag #x9291 :name "SubSecTimeOriginal" :type ascii) + (:tag #x9292 :name "SubSecTimeDigitized" :type ascii) + ;; Tags Relating to Picture-Taking Conditions + (:tag #x829A :name "ExposureTime" :type floatable-rational) + (:tag #x829D :name "FNumber" :type floatable-rational) + (:tag #x8822 :name "ExposureProgram" :type exposure-program) + (:tag #x8824 :name "SpectralSensitivity" :type ascii) + (:tag #x8827 :name "ISOSpeedRatings" :type short) + (:tag #x8828 :name "OECF" :type undefined) + (:tag #x9201 :name "ShutterSpeedValue" :type floatable-rational) + (:tag #x9202 :name "ApertureValue" :type floatable-rational) + (:tag #x9203 :name "BrightnessValue" :type srational) + (:tag #x9204 :name "ExposureBiasValue" :type srational) + (:tag #x9205 :name "MaxApertureValue" :type floatable-rational) + (:tag #x9206 :name "SubjectDistance" :type floatable-rational) + (:tag #x9207 :name "MeteringMode" :type metering-mode) + (:tag #x9208 :name "LightSource" :type light-source) + (:tag #x9209 :name "Flash" :type flash) + (:tag #x920A :name "FocalLength" :type floatable-rational) + (:tag #x9214 :name "SubjectArea" :type short) + (:tag #xA20B :name "FlashEngergy" :type rational) + (:tag #xA20C :name "SpatialFrquencyResponse" :type undefined) + (:tag #xA20E :name "FocalPlaneXResolution" :type floatable-rational) + (:tag #xA20F :name "FocalPlaneYResolution" :type floatable-rational) + (:tag #xA210 :name "FocalPlaneResolutionUnit" :type short) + (:tag #xA214 :name "SubjectLocation" :type short) + (:tag #xA215 :name "ExposureIndex" :type rational) + (:tag #xA217 :name "SensingMethod" :type sensing-method) + (:tag #xA300 :name "FileSource" :type undefined) + (:tag #xA301 :name "SceneType" :type undefined) + (:tag #xA302 :name "CFAPattern" :type undefined) + (:tag #xA401 :name "CustomRendered" :type short) + (:tag #xA402 :name "ExposureMode" :type exposure-mode) + (:tag #xA403 :name "WhiteBalance" :type white-balance) + (:tag #xA404 :name "DigitalZoomRatio" :type rational) + (:tag #xA405 :name "FocalLengthIn35mmFilm" :type short) + (:tag #xA406 :name "SceneCaptureType" :type scene-capture-type) + (:tag #xA407 :name "GainControl" :type rational) + (:tag #xA408 :name "Contrast" :type contrast) + (:tag #xA409 :name "Saturation" :type saturation) + (:tag #xA40A :name "Sharpness" :type sharpness) + (:tag #xA40B :name "DeviceSettingDescription" :type undefined) + (:tag #xA40C :name "SubjectDistanceRange" :type subject-distance-range) + ;; Other Tags + (:tag #xA420 :name "ImageUniqueID" :type ascii)) + +(define-tagset gps + ;; Tags Relating to GPS + (:tag #x0000 :name "GPSVersionID" :type byte) + (:tag #x0001 :name "GPSLatitudeRef" :type ascii) + (:tag #x0002 :name "GPSLatitude" :type rational) + (:tag #x0003 :name "GPSLongitudeRef" :type ascii) + (:tag #x0004 :name "GPSLongitude" :type ascii) + (:tag #x0005 :name "GPSAltitudeRef" :type byte) + (:tag #x0006 :name "GPSAltitude" :type rational) + (:tag #x0007 :name "GPSTimeStamp" :type rational) + (:tag #x0008 :name "GPSSatellites" :type ascii) + (:tag #x0009 :name "GPSStatus" :type ascii) + (:tag #x000A :name "GPSMeasureMode" :type ascii) + (:tag #x000B :name "GPSDOP" :type rational) + (:tag #x000C :name "GPSSpeedRef" :type ascii) + (:tag #x000D :name "GPSSpeed" :type rational) + (:tag #x000E :name "GPSTrackRef" :type ascii) + (:tag #x000F :name "GPSTrack" :type rational) + (:tag #x0010 :name "GPSImgDirectionRef" :type ascii) + (:tag #x0011 :name "GPSImgDirection" :type rational) + (:tag #x0012 :name "GPSMapDatum" :type ascii) + (:tag #x0013 :name "GPSDestLatitudeRef" :type ascii) + (:tag #x0014 :name "GPSDestLatitude" :type rational) + (:tag #x0015 :name "GPSDestLongitudeRef" :type ascii) + (:tag #x0016 :name "GPSDestLongitude" :type rational) + (:tag #x0017 :name "GPSDestBearingRef" :type ascii) + (:tag #x0018 :name "GPSDestBearing" :type rational) + (:tag #x0019 :name "GPSDestDistanceRef" :type ascii) + (:tag #x001A :name "GPSDestDistance" :type rational) + (:tag #x001B :name "GPSProcessingMethod" :type undefined) + (:tag #x001C :name "GPSAreaInformation" :type undefined) + (:tag #x001D :name "GPSDateStamp" :type ascii) + (:tag #x001E :name "GPSDifferential" :type short)) + +(define-tagset interoperability + (:tag #x0001 :name "InteroperabilityIndex" :type ascii)) + +(defun tag-designator (tag tagset) + (etypecase tag + (string (tag-code tag tagset)) + (symbol (tag-code (symbol-name tag) tagset)) + (number tag))) + +(defun ifd-entry (tag ifd) + (when ifd + (let ((tag (tag-designator tag (tagset ifd)))) + (when tag + (bisect-find tag (entries ifd) :key #'tag))))) + +(defun find-ifd-entry (tag exif) + (or (ifd-entry tag (image-ifd exif)) + (ifd-entry tag (exif-ifd exif)) + (ifd-entry tag (gps-ifd exif)))) + +(defun exif-value (tag exif) + (entry-value (find-ifd-entry tag exif))) + +(defun parsed-entry-value (ifd-entry) + (when ifd-entry + (let* ((type (tag-type (tag ifd-entry) (tagset (ifd ifd-entry)))) + (fun (exif-type-parser-fun type))) + (funcall fun (entry-value ifd-entry))))) + +(defun parsed-exif-value (tag exif) + (let ((entry (find-ifd-entry tag exif))) + (when entry + (parsed-entry-value entry)))) + + +(defmethod print-object ((ifd-entry ifd-entry) stream) + (print-unreadable-object (ifd-entry stream :type t :identity t) + (let ((name (or (tag-name (tag ifd-entry) (tagset (ifd ifd-entry))) + "(Unknown Tag)"))) + (format stream "~S #x~X/~D/~D" + name + (tag ifd-entry) + (type ifd-entry) + (count ifd-entry))))) + + +;;; Miscellaneous utility functions + +(defun thumbnail-image (exif) + "Return an (UNSIGNED-BYTE 8) vector containing the JPEG data for the +thumbnail image in EXIF, if present. If there is no thumbnail, return +NIL." + (let ((ifd (thumbnail-ifd exif))) + (flet ((val (tag) + (entry-value (ifd-entry tag ifd)))) + (when ifd + (let ((offset (val "JPEGInterchangeFormat")) + (length (val "JPEGInterchangeFormatLength"))) + (when (and offset length) + (let ((data (make-array length + :element-type '(unsigned-byte 8)))) + (replace data (exif-data exif) + :start2 offset) + data))))))) + +;;; Similar to exifinfo.cl's parse-exif-data + +(defun parse-exif-data (file) + (let ((exif (make-exif file))) + (labels ((val (tag) + (exif-value tag exif)) + (float-val (tag) + (let ((value (val tag))) + (and value (float value))))) + (let* ((flash-value (val "Flash")) + (flash-fired-p (and flash-value (not (logand flash-value 1))))) + (list :file (file exif) + :make (val "Make") + :model (val "Model") + :date (val "DateTime") + :comment nil ; This isn't actually useful + :orientation (val "Orientation") + :exposure (float-val "ExposureTime") + :f-number (float-val "FNumber") + :iso-rating (val "IsoSpeedRatings") + :exposure-bias-value (float-val "ExposureBiasValue") + :subject-distance (float-val "SubjectDistance") + :flash flash-fired-p + :focal-length (float-val "FocalLength") + :image-width (val "PixelXDimension") + :image-length (val "PixelYDimension")))))) + + +(defun ifd-alist (ifd &key parsedp) + "Return all the values in IFD as an alist." + (when ifd + (loop for entry across (entries ifd) + for name = (or (tag-name (tag entry) (tagset ifd)) + (format nil "Unknown Tag #x~4,'0X" (tag entry))) + collect (cons name + (if parsedp + (parsed-entry-value entry) + (entry-value entry)))))) + +(defun exif-alist (exif &key parsedp) + "Return the keys and values from the Image, Exif, and GPS IFDs of EXIF." + (with-slots (image-ifd exif-ifd gps-ifd) + exif + (nconc (ifd-alist image-ifd :parsedp parsedp) + (ifd-alist exif-ifd :parsedp parsedp) + (ifd-alist gps-ifd :parsedp parsedp)))) + diff --git a/zpb-exif.asd b/zpb-exif.asd new file mode 100644 index 0000000..8afbda2 --- /dev/null +++ b/zpb-exif.asd @@ -0,0 +1,42 @@ +;;; +;;; zpb-exif.asd +;;; +;;; Created: 2005-12-08 by Zach Beane +;;; +;;; Copyright (c) 2005 Zachary Beane, All Rights Reserved +;;; +;;; Redistribution and use in source and binary forms, with or without +;;; modification, are permitted provided that the following conditions +;;; are met: +;;; +;;; * Redistributions of source code must retain the above copyright +;;; notice, this list of conditions and the following disclaimer. +;;; +;;; * 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 AUTHOR 'AS IS' AND ANY EXPRESSED +;;; 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 AUTHOR 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. +;;; +;;; $Id: zpb-exif.asd,v 1.2 2009/09/08 17:16:23 xach Exp $ + +(defpackage :zpb-exif-system + (:use :asdf :cl)) + +(in-package :zpb-exif-system) + +(defsystem :zpb-exif + :version "1.2.0" + :author "Zachary Beane " + :components ((:file "exif"))) diff --git a/zpb-exif.html b/zpb-exif.html new file mode 100644 index 0000000..944f9c1 --- /dev/null +++ b/zpb-exif.html @@ -0,0 +1,594 @@ + + +ZPB-EXIF - access to digital image Exif data for Common Lisp + + + + + + +

ZPB-EXIF - access to digital image Exif data for Common Lisp

+ +
+

Abstract

+ +

Exif is a standard for embedding information in an image +file created by a digital camera. ZPB-EXIF is a library that makes +Exif data accessible to Common Lisp programs. It is available under a +BSD-like license. For more info about Exif, see Exif.org. The current version is + 1.2.0, released on September 8, 2009. + + +

Download shortcut: http://www.xach.com/lisp/zpb-exif.tgz +

+ +

Contents

+ +
    +
  1. Overview +
  2. Example +
  3. Terms +
  4. The ZPB-EXIF Dictionary + +
      +
    1. make-exif +
    2. exif-value +
    3. parsed-exif-value +
    4. exif-alist +
    5. ifd-alist +
    6. ifd-entry +
    7. entry-value +
    8. parsed-entry-value +
    9. image-ifd +
    10. exif-ifd +
    11. gps-ifd +
    12. interoperability-ifd +
    13. thumbnail-ifd +
    14. exif-data +
    15. thumbnail-image +
    16. invalid-stream +
    17. invalid-jpeg-stream +
    18. invalid-exif-stream +
    + + + +
  5. Parsed Values +
      +
    1. Image IFD +
    2. Exif IFD +
    + +
  6. Feedback +
+ +

Overview

 + +

Exif data is structured like so: + +

    + +
  • data about an image is separated into multiple sections called +image file directories or IFDs + +
  • each IFD contains one or more key/value pairs called IFD +entries; the key is also called the tag + +
  • there are two mandatory IFDs for an Exif image: the image +IFD and the Exif IFD + +
  • there are a number of optional IFDs: the GPS IFD, the +interoperability IFD, the thumbnail IFD + +
      +
    • the thumbnail IFD may also have separate GPS and interoperability + IFDs, but these are not supported by ZPB-EXIF +
    + +
+ +

ZPB-EXIF provides access to key/value lookup through an object +created from an Exif file or stream. It provides quick access to +image, Exif, and GPS IFD values, and indirect access to other IFDs and +their key/value entries. + +

Example

+ +
+> (defparameter *exif* (make-exif #p"gg_gps.jpg"))
+=> *EXIF*
+
+> (exif-value "FNumber" *exif*)
+=> 9/2
+
+> (parsed-exif-value "MeteringMode" *exif*)
+=> :PATTERN
+
+> (exif-value :DateTimeOriginal *exif*)
+=> "2003:11:23 18:07:37"
+
+> (exif-value #x0112 *exif*)   ; #x0112 => orientation tag in the image IFD
+=> 6
+
+> (parsed-exif-value #x0112 *exif*)
+=> :ROTATED-270
+
+> (exif-value :ISOSpeedRating *exif*)   ; Field not present in this particular image
+=> NIL
+
+> (list (exif-value "GPSLatitude" *exif*)
+        (exif-value "GPSLatitudeRef" *exif*)
+        (exif-value "GPSLongitude" *exif*)
+        (exif-value "GPSLongitudeRef" *exif*))
+=> (#(39 54 56) "N" #(116 23 27) "E")
+
+
+
+
+ +

Terms

 + +
+ +
tag
+ +
an integer that refers to a unique field in a specific IFD. For example, the integer #x0001 represents the InteroperabilityIndex field in the interoperability IFD and the GPSVersionID field in the GPS IFD
+ +
tag designator
+ +
an object representing a tag and that is one of: a string +(denoting a tag named by the string for a given IFD), a symbol +(denoting a tag named by the string that is its name), or a tag +(denoting itself)
+ +
+ +

The ZPB-EXIF Dictionary

 + +

[Function]
+make-exif exif-stream-designator => exif + +

Returns an exif object. exif-stream-designator may +be a stream (designating itself), a pathname (designating the stream +created by opening the file), or a string (treated the same as a +pathname). If +exif-stream-designator does not refer to a JPEG, signals an invalid-jpeg-stream error. If +exif-stream-designator refers to a JPEG, but the JPEG does not +contain any Exif data, signals an invalid-exif-stream error. + +
+ + +

[Function]
+exif-value tag-designator exif => value + +

+ Returns the value of the field identified by + tag-designator from the image IFD, Exif IFD, or GPS IFD. +
+ + +

[Function]
+parsed-exif-value tag-designator exif => +parsed-value + +

+ Returns an the value of the field identified by tag-designator + from the image IFD, Exif IFD, or GPS IFD in parsed form. +
+ + +

[Function]
+exif-alist exif &key parsedp => alist + +

+ Returns an association list that has tag names for keys and IFD entry + values for values for all entries in the image, Exif, and GPS IFDs in + exif. If parsedp is true, the IFD entry values are + in parsed form. +
+ + +

[Function]
+ifd-alist exif &key parsedp => alist + +

+ Returns an association list that has tag names for keys and IFD entry + values for values for the entries ifd. If parsedp is + true, the IFD entry values are in parsed form. +
+ + +

[Function]
+ifd-entry tag-designator ifd => ifd-entry + +

+ Returns the IFD entry identified by tag-designator in + ifd, or NIL if no IFD entry could be found. +
+ + +

[Function]
+entry-value ifd-entry => value + +

+ Returns the value of ifd-entry. +
+ + +

[Function]
+parsed-entry-value ifd-entry => value + +

+ Returns the value of ifd-entry in parsed form. +
+ + +

[Function]
+image-ifd exif => ifd + +

Returns the image IFD for exif. The following tags +may be available in the image IFD: + +

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
TagNameData Type
Tags Relating to Image Data Structure
#x0100ImageWidthshort or long
#x0101ImageHeightshort or long
#x0102BitsPerSampleshort
#x0103Compressionshort
#x0106PhotometricInterpretationshort
#x0112Orientationshort
#x0115SamplesPerPixelshort
#x011CPlanarConfigurationshort
#x0212YCbCrSubSamplingshort
#x0213YCbCrPositioningshort
#x011AXResolutionrational
#x011BYResolutionrational
#x0128ResolutionUnitshort
Tags Relating to Recording Offsets
#x0111StripOffsetsshort or long
#x0116RowsPerStripshort or long
#x0117StripByteCountsshort or long
#x0201JPEGInterchangeFormatlong
#x0202JPEGInterchangeFormatLengthlong
Tags Relating to Image Data Characteristics
#x012DTransferFunctionshort
#x013EWhitePointrational
#x013FPrimaryChromaticitiesrational
#x0211YCbCrCoefficientsrational; parsed value available
#x0214ReferenceBlackWhiterational
Other Tags
#x0132DateTimeascii; parsed value available
#x010EImageDescriptionascii
#x010FMakeascii
#x0110Modelascii
#x0131Softwareascii
#x013BArtistascii
#x8298Copyrightascii
+ + +

+ + +

[Function]
+exif-ifd exif => ifd + +

Returns the Exif IFD for exif. The following tags +may be available in the exif IFD: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
TagNameData Type
Tags Relating to Version
#x9000ExifVersionundefined; parsed value available
#xA000FlashpixVersionundefined
Tags Relating to Image Data Characteristics
#xA001ColorSpaceshort; parsed value available
#xA001Gammarational; parsed value available
#x9101ComponentsConfigurationundefined
#x9102CompressedBitsPerPixelrational
#xA002PixelXDimensionshort or long
#xA003PixelYDimensionshort or long
Tags Relating to User Information
#x927CMakerNoteundefined
#x9286UserCommentundefined; parsed value available
#xA004RelatedSoundFileascii
Tags Relating to Date and Time
#x9003DateTimeOriginalascii; parsed value available
#x9004DateTimeDigitizedascii; parsed value available
#x9290SubSecTimeascii
#x9291SubSecTimeOriginalascii
#x9292SubSecTimeDigitizedascii
Tags Relating to Picture Taking Conditions
#x829AExposureTimerational; parsed value available
#x829DFNumberrational; parsed value available
#x8822ExposureProgramrational; parsed value available
#x8824SpectralSensitivityascii
#x8827ISOSpeedRatingsshort
#x8828OECFundefined
#x9201ShutterSpeedValuesrational; parsed value available
#x9202ApertureValuerational; parsed value available
#x9203BrightnessValuesrational
#x9204ExposureBiasValuesrational
#x9205MaxApertureValuerational; parsed value available
#x9206SubjectDistancerational; parsed value available
#x9207MeteringModeshort; parsed value available
#x9208LightSourceshort; parsed value available
#x9209Flashshort; parsed value available
#x920AFocalLengthrational; parsed value available
#x9214SubjectAreashort
#xA20BFlashEngergyrational
#xA20CSpatialFrquencyResponseundefined
#xA20EFocalPlaneXResolutionrational; parsed value available
#xA20FFocalPlaneYResolutionrational; parsed value available
#xA210FocalPlaneResolutionUnitshort
#xA214SubjectLocationshort
#xA215ExposureIndexrational
#xA217SensingMethodshort; parsed value available
#xA300FileSourceundefined
#xA301SceneTypeundefined
#xA302CFAPatternundefined
#xA401CustomRenderedshort
#xA402ExposureModeshort; parsed value available
#xA403WhiteBalanceshort; parsed value available
#xA404DigitalZoomRatiorational
#xA405FocalLengthIn35mmFilmshort
#xA406SceneCaptureTypeshort; parsed value available
#xA407GainControlrational; parsed value available
#xA408Contrastshort; parsed value available
#xA409Saturationshort; parsed value available
#xA40ASharpnessshort; parsed value available
#xA40BDeviceSettingDescriptionundefined
#xA40CSubjectDistanceRangeshort
#xA420ImageUniqueIDascii
+ + +
+ + +

[Function]
+gps-ifd exif => ifd + +

Returns the GPS IFD for exif. + +

The following tags are available in the GPS IFD: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
TagNameData Type
#x0000GPSVersionIDbyte
#x0001GPSLatitudeRefascii
#x0002GPSLatituderational
#x0003GPSLongitudeRefascii
#x0004GPSLongitudeascii
#x0005GPSAltitudeRefbyte
#x0006GPSAltituderational
#x0007GPSTimeStamprational
#x0008GPSSatellitesascii
#x0009GPSStatusascii
#x000AGPSMeasureModeascii
#x000BGPSDOPrational
#x000CGPSSpeedRefascii
#x000DGPSSpeedrational
#x000EGPSTrackRefascii
#x000FGPSTrackrational
#x0010GPSImgDirectionRefascii
#x0011GPSImgDirectionrational
#x0012GPSMapDatumascii
#x0013GPSDestLatitudeRefascii
#x0014GPSDestLatituderational
#x0015GPSDestLongitudeRefascii
#x0016GPSDestLongituderational
#x0017GPSDestBearingRefascii
#x0018GPSDestBearingrational
#x0019GPSDestDistanceRefascii
#x001AGPSDestDistancerational
+ +

+ + +

[Function]
+interoperability-ifd exif => ifd + +

Returns the interoperability IFD for +exif.
+ +

[Function]
+thumbnail-ifd exif => ifd + +

+ Returns the thumbnail IFD for exif. The tags available are the + same as for the image IFD. +
+ + +

[Function]
+exif-data exif => value + +

+ Returns a vector of (unsigned-byte 8) data representing all + the data in the Exif section of the stream from which exif was + created. +
+ +

[Function]
+thumbnail-image exif => value + +

+ Returns a vector of (unsigned-byte 8) data representing the + embedded Exif thumbnail of exif, or NIL if no Exif thumbnail + is present. +
+ + +

[Condition]
+invalid-stream + +

+ This error condition is a supertype of Exif stream conditions. +
+ + +

[Condition]
+invalid-jpeg-stream + +

+ This condition is signalled when a stream being processed is not a + JPEG stream. It is a subtype of invalid-stream. +
+ + +

[Condition]
+invalid-exif-stream + +

+ This condition is signalled when a stream being processed is not an + Exif stream. It is a subtype of invalid-stream. +
+ + +

Parsed Values

 + +

When using parsed-exif-value, the +following IFD/tag combinations are converted from the "raw" Exif value +into a more processing-friendly format. All others return the same +value that would be returned by exif-value + +

Image IFD

+ +
    + +
  • YCbCrSubsampling: returns one of :CENTERED, + :CO-SITED, or :RESERVED + +
  • DateTime: returns a universal time + +
+ + +

Exif IFD

 + +
    + +
  • ExifVersion: returns a string representing the version, +e.g. "2.1", "2.2", "2.21" + +
  • ColorSpace: returns one of :SRGB, + :UNCALIBRATED, or :RESERVED + +
  • Gamma: returns a float + +
  • UserComment: if the UserComment is in ASCII or Undefined +format, returns a string representing the comment + +
  • DateTimeOriginal: returns a universal time + +
  • DateTimeDigitized: returns a universal time + +
  • ExposureTime: returns a float + +
  • FNumber: returns a float + +
  • ExposureProgram: returns one of :NOT-DEFINED, +:MANUAL, :NORMAL-PROGRAM, +:APERTURE-PRIORITY, :SHUTTER-PRIORITY, +:CREATIVE-PROGRAM, :ACTION-PROGRAM, +:PORTRAIT-MODE, :LANDSCAPE-MODE, or +:RESERVED + +
  • ShutterSpeedValue: returns a float + +
  • ApertureValue: returns a float + +
  • MaxApertureValue: returns a float + +
  • SubjectDistance: returns a float + +
  • MeteringMode: returns one of :UNKNOWN, +:AVERAGE, :CENTER-WEIGHTED-AVERAGE, :SPOT, +:MULTISPOT, :PATTERN, :PARTIAL, +:OTHER, or :RESERVED + +
  • LightSource: returns one of :UNKNOWN, +:DAYLIGHT, :FLOURESCENT, :TUNGSTEN, +:FLASH, :FINE-WEATHER, :CLOUDY-WEATHER, +:SHADE, :DAYLIGHT-FLOURESCENT, +:DAY-WHITE-FLOURESCENT, :COOL-WHITE-FLOURESCENT, +:WHITE-FLOURESCENT, :STANDARD-LIGHT-A, +:STANDARD-LIGHT-B, :STANDARD-LIGHT-C, :D55, +:D65, :D75, :D50, +:ISO-STUDIO-TUNGSTEN, :OTHER-LIGHT-SOURCE, or +:RESERVED. + +
  • Flash: returns T if the flash fired + +
  • FocalLength: returns a float + +
  • FocalPlaneXResolution: returns a float + +
  • FocalPlaneYResolution: returns a float + +
  • SensingMethod: returns one of :NOT-DEFINED, +:ONE-CHIP-COLOR-AREA-SENSOR, +:TWO-CHIP-COLOR-AREA-SENSOR, +:THREE-CHIP-COLOR-AREA-SENSOR, +:COLOR-SEQUENTIAL-AREA-SENSOR, :TRILINEAR-SENSOR, +:COLOR-SEQUENTIAL-LINEAR-SENSOR, or :RESERVED + +
  • ExposureMode: returns one of :AUTO-EXPOSURE, +:MANUAL-EXPOSURE, :AUTO-BRACKET, or +:RESERVED + +
  • WhiteBalance: returns one of :AUTO, +:MANUAL, or :RESERVED + +
  • SceneCaptureType: returns one of :STANDARD, +:LANDSCAPE, :PORTRAIT, :NIGHT-SCENE, or +:RESERVED + +
  • Contrast: returns one of :NORMAL, :SOFT, +:HARD, or :RESERVED + +
  • Saturation: returns one of :NORMAL, +:LOW-SATURATION, :HIGH-SATURATION, or :RESERVED + +
  • Sharpness: returns one of :NORMAL, :SOFT, +:HARD, or :RESERVED + +
+ + +

Feedback

 + +

This library was created by Zachary Beane. For questions, comments, +bug reports, and patches, please email +him. + + +

+$Header: /home/cvs/zpb-exif/zpb-exif.html,v 1.5 2009/09/08 17:16:34 xach Exp $ -- 2.11.4.GIT