add imgcvt

This uses skcms to convert an image into a PNG with a new color profile.

Change-Id: Iaefdbbfba6f4b85637386569a65355df255b980d
Reviewed-on: https://skia-review.googlesource.com/143709
Commit-Queue: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>

1 files changed, 86 insertions, 0 deletions

diff --git a/tools/imgcvt.cpp b/tools/imgcvt.cpp
new file mode 100644
index 0000000000..fe95ded73f
--- /dev/null
+++ b/tools/imgcvt.cpp
@@ -0,0 +1,86 @@
+/*
+* Copyright 2018 Google Inc.
+*
+* Use of this source code is governed by a BSD-style license that can be
+* found in the LICENSE file.
+*/
+
+#include "../third_party/skcms/skcms.h"
+#include "SkColorSpacePriv.h"
+#include "SkData.h"
+#include "SkImage.h"
+#include "SkStream.h"
+
+int main(int argc, char** argv) {
+    const char* image_path = argc > 1 ? argv[1] : nullptr;
+    if (!image_path) {
+        SkDebugf("Please pass an image to convert as the first argument to this program.\n");
+        return 1;
+    }
+
+    sk_sp<SkImage> image = SkImage::MakeFromEncoded(SkData::MakeFromFileName(image_path));
+    if (!image) {
+        SkDebugf("Couldn't decode %s as an SkImage.\n", image_path);
+        return 1;
+    }
+
+    image = image->makeRasterImage();
+    if (!image) {
+        SkDebugf("Converting to raster image failed.\n");
+        return 1;
+    }
+
+    SkPixmap pixmap;
+    if (!image->peekPixels(&pixmap)) {
+        SkDebugf("We really should be able to peek raster pixels.\n");
+        return 1;
+    }
+
+    SkColorSpace* src_cs = image->colorSpace() ? image->colorSpace()
+                                               : sk_srgb_singleton();
+    skcms_ICCProfile src_profile;
+    src_cs->toProfile(&src_profile);
+
+    const char* dst_profile_path = argc > 2 ? argv[2] : nullptr;
+    skcms_ICCProfile dst_profile = *skcms_sRGB_profile();
+    if (dst_profile_path) {
+        sk_sp<SkData> blob = SkData::MakeFromFileName(dst_profile_path);
+        if (!skcms_Parse(blob->data(), blob->size(), &dst_profile)) {
+            SkDebugf("Can't parse %s as an ICC profile.\n", dst_profile_path);
+            return 1;
+        }
+    }
+
+    skcms_PixelFormat fmt;
+    switch (pixmap.colorType()) {
+        case kRGBA_8888_SkColorType: fmt = skcms_PixelFormat_RGBA_8888; break;
+        case kBGRA_8888_SkColorType: fmt = skcms_PixelFormat_BGRA_8888; break;
+        default:
+            SkDebugf("color type %d not yet supported, imgcvt.cpp needs an update.\n",
+                     pixmap.colorType());
+            return 1;
+    }
+
+    if (pixmap.alphaType() != kPremul_SkAlphaType) {
+        SkDebugf("not premul, that's weird.\n");
+        return 1;
+    }
+    auto alpha = skcms_AlphaFormat_PremulAsEncoded;
+
+    if (pixmap.rowBytes() != (size_t)pixmap.width() * pixmap.info().bytesPerPixel()) {
+        SkDebugf("not a tight pixmap, need a loop here\n");
+        return 1;
+    }
+
+    skcms_Transform(pixmap.addr(),          fmt,alpha, &src_profile,
+                    pixmap.writable_addr(), fmt,alpha, &dst_profile,
+                    pixmap.width() * pixmap.height());
+    pixmap.setColorSpace(SkColorSpace::Make(dst_profile));
+
+    sk_sp<SkImage> transformed = SkImage::MakeRasterCopy(pixmap);
+    sk_sp<SkData>  png = transformed->encodeToData();
+
+    SkFILEWStream("transformed.png").write(png->data(), png->size());
+
+    return 0;
+}