Add qcms library for applying ICC color profile transforms to images. This...

third_party/qcms/iccread.c

+//  qcms
+//  Copyright (C) 2009 Mozilla Foundation
+//  Copyright (C) 1998-2007 Marti Maria
+//
+// Permission is hereby granted, free of charge, to any person obtaining 
+// a copy of this software and associated documentation files (the "Software"), 
+// to deal in the Software without restriction, including without limitation 
+// the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+// and/or sell copies of the Software, and to permit persons to whom the Software 
+// is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in 
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO 
+// THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 
+// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
+// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include <math.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include "qcmsint.h"
+
+typedef uint32_t be32;
+typedef uint16_t be16;
+
+#if 0
+not used yet
+/* __builtin_bswap isn't available in older gccs
+ * so open code it for now */
+static be32 cpu_to_be32(int32_t v)
+{
+#ifdef IS_LITTLE_ENDIAN
+        return ((v & 0xff) << 24) | ((v & 0xff00) << 8) | ((v & 0xff0000) >> 8) | ((v & 0xff000000) >> 24);
+        //return __builtin_bswap32(v);
+        return v;
+#endif
+}
+#endif
+
+static uint32_t be32_to_cpu(be32 v)
+{
+#ifdef IS_LITTLE_ENDIAN
+        return ((v & 0xff) << 24) | ((v & 0xff00) << 8) | ((v & 0xff0000) >> 8) | ((v & 0xff000000) >> 24);
+        //return __builtin_bswap32(v);
+#else
+        return v;
+#endif
+}
+
+static uint16_t be16_to_cpu(be16 v)
+{
+#ifdef IS_LITTLE_ENDIAN
+        return ((v & 0xff) << 8) | ((v & 0xff00) >> 8);
+#else
+        return v;
+#endif
+}
+
+/* a wrapper around the memory that we are going to parse
+ * into a qcms_profile */
+struct mem_source
+{
+        const unsigned char *buf;
+        size_t size;
+        qcms_bool valid;
+        const char *invalid_reason;
+};
+
+static void invalid_source(struct mem_source *mem, const char *reason)
+{
+        mem->valid = false;
+        mem->invalid_reason = reason;
+}
+
+static uint32_t read_u32(struct mem_source *mem, size_t offset)
+{
+        /* Subtract from mem->size instead of the more intuitive adding to offset.
+         * This avoids overflowing offset. The subtraction is safe because
+         * mem->size is guaranteed to be > 4 */
+        if (offset > mem->size - 4) {
+                invalid_source(mem, "Invalid offset");
+                return 0;
+        } else {
+                be32 k;
+                memcpy(&k, mem->buf + offset, sizeof(k));
+                return be32_to_cpu(k);
+        }
+}
+
+static uint16_t read_u16(struct mem_source *mem, size_t offset)
+{
+        if (offset > mem->size - 2) {
+                invalid_source(mem, "Invalid offset");
+                return 0;
+        } else {
+                be16 k;
+                memcpy(&k, mem->buf + offset, sizeof(k));
+                return be16_to_cpu(k);
+        }
+}
+
+static uint8_t read_u8(struct mem_source *mem, size_t offset)
+{
+        if (offset > mem->size - 1) {
+                invalid_source(mem, "Invalid offset");
+                return 0;
+        } else {
+                return *(uint8_t*)(mem->buf + offset);
+        }
+}
+
+static s15Fixed16Number read_s15Fixed16Number(struct mem_source *mem, size_t offset)
+{
+        return read_u32(mem, offset);
+}
+
+#if 0
+static uInt16Number read_uInt16Number(struct mem_source *mem, size_t offset)
+{
+        return read_u16(mem, offset);
+}
+#endif
+
+#define BAD_VALUE_PROFILE NULL
+#define INVALID_PROFILE NULL
+#define NO_MEM_PROFILE NULL
+
+/* An arbitrary 4MB limit on profile size */
+#define MAX_PROFILE_SIZE 1024*1024*4
+#define MAX_TAG_COUNT 1024
+
+static void check_CMM_type_signature(struct mem_source *src)
+{
+        //uint32_t CMM_type_signature = read_u32(src, 4);
+        //TODO: do the check?
+
+}
+
+static void check_profile_version(struct mem_source *src)
+{
+        uint8_t major_revision = read_u8(src, 8 + 0);
+        uint8_t minor_revision = read_u8(src, 8 + 1);
+        uint8_t reserved1      = read_u8(src, 8 + 2);
+        uint8_t reserved2      = read_u8(src, 8 + 3);
+        if (major_revision != 0x4) {
+                if (major_revision > 0x2)
+                        invalid_source(src, "Unsupported major revision");
+                if (minor_revision > 0x40)
+                        invalid_source(src, "Unsupported minor revision");
+        }
+        if (reserved1 != 0 || reserved2 != 0)
+                invalid_source(src, "Invalid reserved bytes");
+}
+
+#define INPUT_DEVICE_PROFILE   0x73636e72 // 'scnr'
+#define DISPLAY_DEVICE_PROFILE 0x6d6e7472 // 'mntr'
+#define OUTPUT_DEVICE_PROFILE  0x70727472 // 'prtr'
+#define DEVICE_LINK_PROFILE    0x6c696e6b // 'link'
+#define COLOR_SPACE_PROFILE    0x73706163 // 'spac'
+#define ABSTRACT_PROFILE       0x61627374 // 'abst'
+#define NAMED_COLOR_PROFILE    0x6e6d636c // 'nmcl'
+
+static void read_class_signature(qcms_profile *profile, struct mem_source *mem)
+{
+        profile->class = read_u32(mem, 12);
+        switch (profile->class) {
+                case DISPLAY_DEVICE_PROFILE:
+                case INPUT_DEVICE_PROFILE:
+                        break;
+                case OUTPUT_DEVICE_PROFILE:
+                default:
+                        invalid_source(mem, "Invalid  Profile/Device Class signature");
+        }
+}
+
+static void read_color_space(qcms_profile *profile, struct mem_source *mem)
+{
+        profile->color_space = read_u32(mem, 16);
+        switch (profile->color_space) {
+                case RGB_SIGNATURE:
+                case GRAY_SIGNATURE:
+                        break;
+                default:
+                        invalid_source(mem, "Unsupported colorspace");
+        }
+}
+
+struct tag
+{
+        uint32_t signature;
+        uint32_t offset;
+        uint32_t size;
+};
+
+struct tag_index {
+        uint32_t count;
+        struct tag *tags;
+};
+
+static struct tag_index read_tag_table(qcms_profile *profile, struct mem_source *mem)
+{
+        struct tag_index index = {0, NULL};
+        unsigned int i;
+
+        index.count = read_u32(mem, 128);
+        if (index.count > MAX_TAG_COUNT) {
+                invalid_source(mem, "max number of tags exceeded");
+                return index;
+        }
+
+        index.tags = malloc(sizeof(struct tag)*index.count);
+        if (index.tags) {
+                for (i = 0; i < index.count; i++) {
+                        index.tags[i].signature = read_u32(mem, 128 + 4 + 4*i*3);
+                        index.tags[i].offset    = read_u32(mem, 128 + 4 + 4*i*3 + 4);
+                        index.tags[i].size      = read_u32(mem, 128 + 4 + 4*i*3 + 8);
+                }
+        }
+
+        return index;
+}
+
+// Checks a profile for obvious inconsistencies and returns
+// true if the profile looks bogus and should probably be
+// ignored.
+qcms_bool qcms_profile_is_bogus(qcms_profile *profile)
+{
+       float sum[3], target[3], tolerance[3];
+       float rX, rY, rZ, gX, gY, gZ, bX, bY, bZ;
+       bool negative;
+       unsigned i;
+
+       // We currently only check the bogosity of RGB profiles
+       if (profile->color_space != RGB_SIGNATURE)
+               return false;
+
+       rX = s15Fixed16Number_to_float(profile->redColorant.X);
+       rY = s15Fixed16Number_to_float(profile->redColorant.Y);
+       rZ = s15Fixed16Number_to_float(profile->redColorant.Z);
+
+       gX = s15Fixed16Number_to_float(profile->greenColorant.X);
+       gY = s15Fixed16Number_to_float(profile->greenColorant.Y);
+       gZ = s15Fixed16Number_to_float(profile->greenColorant.Z);
+
+       bX = s15Fixed16Number_to_float(profile->blueColorant.X);
+       bY = s15Fixed16Number_to_float(profile->blueColorant.Y);
+       bZ = s15Fixed16Number_to_float(profile->blueColorant.Z);
+
+       // Check if any of the XYZ values are negative (see mozilla bug 498245)
+       // CIEXYZ tristimulus values cannot be negative according to the spec.
+       negative =
+               (rX < 0) || (rY < 0) || (rZ < 0) ||
+               (gX < 0) || (gY < 0) || (gZ < 0) ||
+               (bX < 0) || (bY < 0) || (bZ < 0);
+
+       if (negative)
+               return true;
+
+
+       // Sum the values; they should add up to something close to white
+       sum[0] = rX + gX + bX;
+       sum[1] = rY + gY + bY;
+       sum[2] = rZ + gZ + bZ;
+
+       // Build our target vector (see mozilla bug 460629)
+       target[0] = 0.96420;
+       target[1] = 1.00000;
+       target[2] = 0.82491;
+
+       // Our tolerance vector - Recommended by Chris Murphy based on
+       // conversion from the LAB space criterion of no more than 3 in any one
+       // channel. This is similar to, but slightly more tolerant than Adobe's
+       // criterion.
+       tolerance[0] = 0.02;
+       tolerance[1] = 0.02;
+       tolerance[2] = 0.04;
+
+       // Compare with our tolerance
+       for (i = 0; i < 3; ++i) {
+           if (!(((sum[i] - tolerance[i]) <= target[i]) &&
+                 ((sum[i] + tolerance[i]) >= target[i])))
+               return true;
+       }
+
+       // All Good
+       return false;
+}
+
+#define TAG_bXYZ 0x6258595a
+#define TAG_gXYZ 0x6758595a
+#define TAG_rXYZ 0x7258595a
+#define TAG_rTRC 0x72545243
+#define TAG_bTRC 0x62545243
+#define TAG_gTRC 0x67545243
+#define TAG_kTRC 0x6b545243
+#define TAG_A2B0 0x41324230
+
+static struct tag *find_tag(struct tag_index index, uint32_t tag_id)
+{
+        unsigned int i;
+        struct tag *tag = NULL;
+        for (i = 0; i < index.count; i++) {
+                if (index.tags[i].signature == tag_id) {
+                        return &index.tags[i];
+                }
+        }
+        return tag;
+}
+
+#define XYZ_TYPE   0x58595a20 // 'XYZ '
+#define CURVE_TYPE 0x63757276 // 'curv'
+#define LUT16_TYPE 0x6d667432 // 'mft2'
+#define LUT8_TYPE  0x6d667431 // 'mft1'
+
+static struct XYZNumber read_tag_XYZType(struct mem_source *src, struct tag_index index, uint32_t tag_id)
+{
+        struct XYZNumber num = {0, 0, 0};
+        struct tag *tag = find_tag(index, tag_id);
+        if (tag) {
+                uint32_t offset = tag->offset;
+
+                uint32_t type = read_u32(src, offset);
+                if (type != XYZ_TYPE)
+                        invalid_source(src, "unexpected type, expected XYZ");
+                num.X = read_s15Fixed16Number(src, offset+8);
+                num.Y = read_s15Fixed16Number(src, offset+12);
+                num.Z = read_s15Fixed16Number(src, offset+16);
+        } else {
+                invalid_source(src, "missing xyztag");
+        }
+        return num;
+}
+
+static struct curveType *read_tag_curveType(struct mem_source *src, struct tag_index index, uint32_t tag_id)
+{
+        struct tag *tag = find_tag(index, tag_id);
+        struct curveType *curve = NULL;
+        if (tag) {
+                uint32_t offset = tag->offset;
+                uint32_t type = read_u32(src, offset);
+                uint32_t count = read_u32(src, offset+8);
+                unsigned int i;
+
+                if (type != CURVE_TYPE) {
+                        invalid_source(src, "unexpected type, expected CURV");
+                        return NULL;
+                }
+
+#define MAX_CURVE_ENTRIES 40000 //arbitrary
+                if (count > MAX_CURVE_ENTRIES) {
+                        invalid_source(src, "curve size too large");
+                        return NULL;
+                }
+                curve = malloc(sizeof(struct curveType) + sizeof(uInt16Number)*count);
+                if (!curve)
+                        return NULL;
+
+                curve->count = count;
+                for (i=0; i<count; i++) {
+                        curve->data[i] = read_u16(src, offset + 12 + i *2);
+                }
+        } else {
+                invalid_source(src, "missing curvetag");
+        }
+
+        return curve;
+}
+
+/* This function's not done yet */
+static struct lutType *read_tag_lutType(struct mem_source *src, struct tag_index index, uint32_t tag_id)
+{
+        struct tag *tag = find_tag(index, tag_id);
+        uint32_t offset = tag->offset;
+        uint32_t type = read_u32(src, offset);
+        uint16_t num_input_table_entries;
+        uint16_t num_output_table_entries;
+        uint8_t in_chan, grid_points, out_chan;
+        uint32_t clut_size;
+        struct lutType *lut;
+        int i;
+
+        num_input_table_entries  = read_u16(src, offset + 48);
+        num_output_table_entries = read_u16(src, offset + 50);
+
+        in_chan     = read_u8(src, offset + 8);
+        out_chan    = read_u8(src, offset + 9);
+        grid_points = read_u8(src, offset + 10);
+
+        if (!src->valid)
+                return NULL;
+
+        clut_size = in_chan * grid_points * out_chan;
+#define MAX_CLUT_SIZE 10000 // arbitrary
+        if (clut_size > MAX_CLUT_SIZE) {
+                return NULL;
+        }
+
+        if (type != LUT16_TYPE && type != LUT8_TYPE)
+                return NULL;
+
+        lut = malloc(sizeof(struct lutType) + (clut_size + num_input_table_entries + num_output_table_entries)*sizeof(uint8_t));
+        if (!lut)
+                return NULL;
+        lut->num_input_channels   = read_u8(src, offset + 8);
+        lut->num_output_channels  = read_u8(src, offset + 9);
+        lut->num_clut_grid_points = read_u8(src, offset + 10);
+        lut->e00 = read_s15Fixed16Number(src, offset+12);
+        lut->e01 = read_s15Fixed16Number(src, offset+16);
+        lut->e02 = read_s15Fixed16Number(src, offset+20);
+        lut->e10 = read_s15Fixed16Number(src, offset+24);
+        lut->e11 = read_s15Fixed16Number(src, offset+28);
+        lut->e12 = read_s15Fixed16Number(src, offset+32);
+        lut->e20 = read_s15Fixed16Number(src, offset+36);
+        lut->e21 = read_s15Fixed16Number(src, offset+40);
+        lut->e22 = read_s15Fixed16Number(src, offset+44);
+
+        //TODO: finish up
+        return lut;
+}
+
+static void read_rendering_intent(qcms_profile *profile, struct mem_source *src)
+{
+        profile->rendering_intent = read_u32(src, 64);
+        switch (profile->rendering_intent) {
+                case QCMS_INTENT_PERCEPTUAL:
+                case QCMS_INTENT_SATURATION:
+                case QCMS_INTENT_RELATIVE_COLORIMETRIC:
+                case QCMS_INTENT_ABSOLUTE_COLORIMETRIC:
+                        break;
+                default:
+                        invalid_source(src, "unknown rendering intent");
+        }
+}
+
+qcms_profile *qcms_profile_create(void)
+{
+        return calloc(sizeof(qcms_profile), 1);
+}
+
+/* build sRGB gamma table */
+/* based on cmsBuildParametricGamma() */
+static uint16_t *build_sRGB_gamma_table(int num_entries)
+{
+        int i;
+        /* taken from lcms: Build_sRGBGamma() */
+        double gamma = 2.4;
+        double a = 1./1.055;
+        double b = 0.055/1.055;
+        double c = 1./12.92;
+        double d = 0.04045;
+
+        uint16_t *table = malloc(sizeof(uint16_t) * num_entries);
+        if (!table)
+                return NULL;
+
+        for (i=0; i<num_entries; i++) {
+                double x = (double)i / (num_entries-1);
+                double y, output;
+                // IEC 61966-2.1 (sRGB)
+                // Y = (aX + b)^Gamma | X >= d
+                // Y = cX             | X < d
+                if (x >= d) {
+                        double e = (a*x + b);
+                        if (e > 0)
+                                y = pow(e, gamma);
+                        else
+                                y = 0;
+                } else {
+                        y = c*x;
+                }
+
+                // Saturate -- this could likely move to a separate function
+                output = y * 65535. + .5;
+                if (output > 65535.)
+                        output = 65535;
+                if (output < 0)
+                        output = 0;
+                table[i] = (uint16_t)floor(output);
+        }
+        return table;
+}
+
+static struct curveType *curve_from_table(uint16_t *table, int num_entries)
+{
+        struct curveType *curve;
+        int i;
+        curve = malloc(sizeof(struct curveType) + sizeof(uInt16Number)*num_entries);
+        if (!curve)
+                return NULL;
+        curve->count = num_entries;
+        for (i = 0; i < num_entries; i++) {
+                curve->data[i] = table[i];
+        }
+        return curve;
+}
+
+static uint16_t float_to_u8Fixed8Number(float a)
+{
+        if (a > (255. + 255./256))
+                return 0xffff;
+        else if (a < 0.)
+                return 0;
+        else
+                return floor(a*256. + .5);
+}
+
+static struct curveType *curve_from_gamma(float gamma)
+{
+        struct curveType *curve;
+        int num_entries = 1;
+        curve = malloc(sizeof(struct curveType) + sizeof(uInt16Number)*num_entries);
+        if (!curve)
+                return NULL;
+        curve->count = num_entries;
+        curve->data[0] = float_to_u8Fixed8Number(gamma);
+        return curve;
+}
+
+static void qcms_profile_fini(qcms_profile *profile)
+{
+        free(profile->redTRC);
+        free(profile->blueTRC);
+        free(profile->greenTRC);
+        free(profile->grayTRC);
+        free(profile);
+}
+
+//XXX: it would be nice if we had a way of ensuring
+// everything in a profile was initialized regardless of how it was created
+
+//XXX: should this also be taking a black_point?
+/* similar to CGColorSpaceCreateCalibratedRGB */
+qcms_profile* qcms_profile_create_rgb_with_gamma(
+                qcms_CIE_xyY white_point,
+                qcms_CIE_xyYTRIPLE primaries,
+                float gamma)
+{
+        qcms_profile* profile = qcms_profile_create();
+        if (!profile)
+                return NO_MEM_PROFILE;
+
+        //XXX: should store the whitepoint
+        if (!set_rgb_colorants(profile, white_point, primaries)) {
+                qcms_profile_fini(profile);
+                return INVALID_PROFILE;
+        }
+
+        profile->redTRC = curve_from_gamma(gamma);
+        profile->blueTRC = curve_from_gamma(gamma);
+        profile->greenTRC = curve_from_gamma(gamma);
+
+        if (!profile->redTRC || !profile->blueTRC || !profile->greenTRC) {
+                qcms_profile_fini(profile);
+                return NO_MEM_PROFILE;
+        }
+        profile->class = DISPLAY_DEVICE_PROFILE;
+        profile->rendering_intent = QCMS_INTENT_PERCEPTUAL;
+        profile->color_space = RGB_SIGNATURE;
+        return profile;
+}
+
+qcms_profile* qcms_profile_create_rgb_with_table(
+                qcms_CIE_xyY white_point,
+                qcms_CIE_xyYTRIPLE primaries,
+                uint16_t *table, int num_entries)
+{
+        qcms_profile* profile = qcms_profile_create();
+        if (!profile)
+                return NO_MEM_PROFILE;
+
+        //XXX: should store the whitepoint
+        if (!set_rgb_colorants(profile, white_point, primaries)) {
+                qcms_profile_fini(profile);
+                return INVALID_PROFILE;
+        }
+
+        profile->redTRC = curve_from_table(table, num_entries);
+        profile->blueTRC = curve_from_table(table, num_entries);
+        profile->greenTRC = curve_from_table(table, num_entries);
+
+        if (!profile->redTRC || !profile->blueTRC || !profile->greenTRC) {
+                qcms_profile_fini(profile);
+                return NO_MEM_PROFILE;
+        }
+        profile->class = DISPLAY_DEVICE_PROFILE;
+        profile->rendering_intent = QCMS_INTENT_PERCEPTUAL;
+        profile->color_space = RGB_SIGNATURE;
+        return profile;
+}
+
+/* from lcms: cmsWhitePointFromTemp */
+/* tempK must be >= 4000. and <= 25000.
+ * similar to argyll: icx_DTEMP2XYZ() */
+static qcms_CIE_xyY white_point_from_temp(int temp_K)
+{
+        qcms_CIE_xyY white_point;
+        double x, y;
+        double T, T2, T3;
+        // double M1, M2;
+
+        // No optimization provided.
+        T = temp_K;
+        T2 = T*T;            // Square
+        T3 = T2*T;           // Cube
+
+        // For correlated color temperature (T) between 4000K and 7000K:
+        if (T >= 4000. && T <= 7000.) {
+                x = -4.6070*(1E9/T3) + 2.9678*(1E6/T2) + 0.09911*(1E3/T) + 0.244063;
+        } else {
+                // or for correlated color temperature (T) between 7000K and 25000K:
+                if (T > 7000.0 && T <= 25000.0) {
+                        x = -2.0064*(1E9/T3) + 1.9018*(1E6/T2) + 0.24748*(1E3/T) + 0.237040;
+                } else {
+                        assert(0 && "invalid temp");
+                }
+        }
+
+        // Obtain y(x)
+
+        y = -3.000*(x*x) + 2.870*x - 0.275;
+
+        // wave factors (not used, but here for futures extensions)
+
+        // M1 = (-1.3515 - 1.7703*x + 5.9114 *y)/(0.0241 + 0.2562*x - 0.7341*y);
+        // M2 = (0.0300 - 31.4424*x + 30.0717*y)/(0.0241 + 0.2562*x - 0.7341*y);
+
+        // Fill white_point struct
+        white_point.x = x;
+        white_point.y = y;
+        white_point.Y = 1.0;
+
+        return white_point;
+}
+
+qcms_profile* qcms_profile_sRGB(void)
+{
+        qcms_profile *profile;
+        uint16_t *table;
+
+        qcms_CIE_xyYTRIPLE Rec709Primaries = {
+                {0.6400, 0.3300, 1.0},
+                {0.3000, 0.6000, 1.0},
+                {0.1500, 0.0600, 1.0}
+        };
+        qcms_CIE_xyY D65;
+
+        D65 = white_point_from_temp(6504);
+
+        table = build_sRGB_gamma_table(1024);
+
+        if (!table)
+                return NO_MEM_PROFILE;
+
+        profile = qcms_profile_create_rgb_with_table(D65, Rec709Primaries, table, 1024);
+        free(table);
+        return profile;
+}
+
+
+/* qcms_profile_from_memory does not hold a reference to the memory passed in */
+qcms_profile* qcms_profile_from_memory(const void *mem, size_t size)
+{
+        uint32_t length;
+        struct mem_source source;
+        struct mem_source *src = &source;
+        struct tag_index index;
+        qcms_profile *profile;
+
+        source.buf = mem;
+        source.size = size;
+        source.valid = true;
+
+        length = read_u32(src, 0);
+        if (length <= size) {
+                // shrink the area that we can read if appropriate
+                source.size = length;
+        } else {
+                return INVALID_PROFILE;
+        }
+
+        /* ensure that the profile size is sane so it's easier to reason about */
+        if (source.size <= 64 || source.size >= MAX_PROFILE_SIZE)
+                return INVALID_PROFILE;
+
+        profile = qcms_profile_create();
+        if (!profile)
+                return NO_MEM_PROFILE;
+
+        check_CMM_type_signature(src);
+        check_profile_version(src);
+        read_class_signature(profile, src);
+        read_rendering_intent(profile, src);
+        read_color_space(profile, src);
+        //TODO read rest of profile stuff
+
+        if (!src->valid)
+                goto invalid_profile;
+
+        index = read_tag_table(profile, src);
+        if (!src->valid || !index.tags)
+                goto invalid_tag_table;
+
+        if (profile->class == DISPLAY_DEVICE_PROFILE || profile->class == INPUT_DEVICE_PROFILE) {
+                if (profile->color_space == RGB_SIGNATURE) {
+
+                        profile->redColorant = read_tag_XYZType(src, index, TAG_rXYZ);
+                        profile->blueColorant = read_tag_XYZType(src, index, TAG_bXYZ);
+                        profile->greenColorant = read_tag_XYZType(src, index, TAG_gXYZ);
+
+                        if (!src->valid)
+                                goto invalid_tag_table;
+
+                        profile->redTRC = read_tag_curveType(src, index, TAG_rTRC);
+                        profile->blueTRC = read_tag_curveType(src, index, TAG_bTRC);
+                        profile->greenTRC = read_tag_curveType(src, index, TAG_gTRC);
+
+                        if (!profile->redTRC || !profile->blueTRC || !profile->greenTRC)
+                                goto invalid_tag_table;
+
+                } else if (profile->color_space == GRAY_SIGNATURE) {
+
+                        profile->grayTRC = read_tag_curveType(src, index, TAG_kTRC);
+                        if (!profile->grayTRC)
+                                goto invalid_tag_table;
+
+                } else {
+                        goto invalid_tag_table;
+                }
+        } else if (0 && profile->class == OUTPUT_DEVICE_PROFILE) {
+                profile->A2B0 = read_tag_lutType(src, index, TAG_A2B0);
+        } else {
+                goto invalid_tag_table;
+        }
+
+        if (!src->valid)
+                goto invalid_tag_table;
+
+        free(index.tags);
+
+        return profile;
+
+invalid_tag_table:
+        free(index.tags);
+invalid_profile:
+        qcms_profile_fini(profile);
+        return INVALID_PROFILE;
+}
+
+qcms_intent qcms_profile_get_rendering_intent(qcms_profile *profile)
+{
+        return profile->rendering_intent;
+}
+
+icColorSpaceSignature
+qcms_profile_get_color_space(qcms_profile *profile)
+{
+        return profile->color_space;
+}
+
+void qcms_profile_release(qcms_profile *profile)
+{
+        if (profile->output_table_r)
+                precache_release(profile->output_table_r);
+        if (profile->output_table_g)
+                precache_release(profile->output_table_g);
+        if (profile->output_table_b)
+                precache_release(profile->output_table_b);
+
+        qcms_profile_fini(profile);
+}
+
+#include <stdio.h>
+qcms_profile* qcms_profile_from_file(FILE *file)
+{
+        uint32_t length, remaining_length;
+        qcms_profile *profile;
+        size_t read_length;
+        be32 length_be;
+        void *data;
+
+        fread(&length_be, sizeof(length), 1, file);
+        length = be32_to_cpu(length_be);
+        if (length > MAX_PROFILE_SIZE)
+                return BAD_VALUE_PROFILE;
+
+        /* allocate room for the entire profile */
+        data = malloc(length);
+        if (!data)
+                return NO_MEM_PROFILE;
+
+        /* copy in length to the front so that the buffer will contain the entire profile */
+        *((be32*)data) = length_be;
+        remaining_length = length - sizeof(length_be);
+
+        /* read the rest profile */
+        read_length = fread((unsigned char*)data + sizeof(length_be), 1, remaining_length, file);
+        if (read_length != remaining_length) {
+                free(data);
+                return INVALID_PROFILE;
+        }
+
+        profile = qcms_profile_from_memory(data, length);
+        free(data);
+        return profile;
+}
+
+qcms_profile* qcms_profile_from_path(const char *path)
+{
+        qcms_profile *profile = NULL;
+        FILE *file = fopen(path, "rb");
+        if (file) {
+                profile = qcms_profile_from_file(file);
+                fclose(file);
+        }
+        return profile;
+}