Jaesung Chung | 2934553 | 2016-01-14 02:28:47 +0900 | [diff] [blame] | 1 | // Copyright 2015 Google Inc. |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | // |
| 15 | //////////////////////////////////////////////////////////////////////////////// |
| 16 | // |
| 17 | // The purpose of the preview-image-extractor (piex) is to find and extract the |
| 18 | // largest JPEG compressed preview image contained in a RAW file. |
Jaesung Chung | 2934553 | 2016-01-14 02:28:47 +0900 | [diff] [blame] | 19 | // |
| 20 | // Even for unsupported RAW files we want to provide high quality images using a |
| 21 | // dedicated, small and portable library. That is possible by taking the preview |
| 22 | // image contained in all RAW files. |
| 23 | // |
| 24 | // Typically a preview image is stored as JPEG compressed, full size (or at |
| 25 | // least half size) image in a RAW file. |
| 26 | // |
| 27 | // A typical client code snippet: |
| 28 | // |
| 29 | // // In C++ |
| 30 | // PreviewImageData image_data; |
| 31 | // unique_ptr<StreamInterface> data_stream(new DataStream(file)); |
| 32 | // Error err = GetPreviewImageData(data_stream.get(), &image_data)); |
| 33 | // if (err == Error::kFail) { |
| 34 | // // The input data seems to be broken. |
| 35 | // return; |
| 36 | // } else if (err == Error::kUnsupported) { |
| 37 | // // The input data is not supported. |
| 38 | // return; |
| 39 | // } |
| 40 | // |
| 41 | // // Uncompress the JPEG as usual, e.g. on Android with the BitmapFactory: |
| 42 | // // In Java |
| 43 | // Bitmap bitmap = BitmapFactory.decodeByteArray( |
Yujie Qin | 3eaa831 | 2016-01-15 16:22:20 +0100 | [diff] [blame] | 44 | // file.at(image_data.preview_offset), image_data.preview_length); |
Jaesung Chung | 2934553 | 2016-01-14 02:28:47 +0900 | [diff] [blame] | 45 | |
| 46 | #ifndef PIEX_PIEX_H_ |
| 47 | #define PIEX_PIEX_H_ |
| 48 | |
| 49 | #include <string> |
| 50 | #include <vector> |
| 51 | |
| 52 | #include "src/piex_types.h" |
| 53 | |
| 54 | namespace piex { |
| 55 | |
| 56 | // Returns the maximum number of bytes IsRaw() will read from the stream. |
| 57 | size_t BytesRequiredForIsRaw(); |
| 58 | |
| 59 | // Returns true if 'data' contains a RAW file format, even if it is not |
| 60 | // supported by Piex, false otherwise. Reads at most BytesRequiredForIsRaw() |
| 61 | // from the stream. |
| 62 | bool IsRaw(StreamInterface* data); |
| 63 | |
| 64 | // Gets the largest JPEG compressed preview image data. On success |
| 65 | // 'preview_image_data' contains image metadata, the unverified length and the |
| 66 | // offset to a JPEG compressed image from the beginning of the file. |
| 67 | // |
| 68 | // Returns 'kFail' when something with the data is wrong. |
| 69 | // Returns 'kUnsupported' if file format is not supported. |
| 70 | // |
Yujie Qin | 3eaa831 | 2016-01-15 16:22:20 +0100 | [diff] [blame] | 71 | // One could check the "preview_image_data->preview_length != 0" for the |
| 72 | // existance of a preview image. |
Jaesung Chung | 2934553 | 2016-01-14 02:28:47 +0900 | [diff] [blame] | 73 | Error GetPreviewImageData(StreamInterface* data, |
| 74 | PreviewImageData* preview_image_data); |
| 75 | |
Yujie Qin | 2f5d8ea | 2016-04-06 12:55:08 +0200 | [diff] [blame] | 76 | // Returns true if the full width and height and the mosaic pattern dimension of |
| 77 | // a DNG image could be obtained. False otherwise. |
| 78 | bool GetDngInformation(StreamInterface* data, std::uint32_t* width, |
| 79 | std::uint32_t* height, |
| 80 | std::vector<std::uint32_t>* cfa_pattern_dim); |
| 81 | |
| 82 | // Returns true if Exif orientation for the image can be obtained. False |
| 83 | // otherwise. |
| 84 | bool GetOrientation(StreamInterface* data, std::uint32_t* orientation); |
| 85 | |
Jaesung Chung | 2934553 | 2016-01-14 02:28:47 +0900 | [diff] [blame] | 86 | // Returns a vector of upper case file extensions, which are used as a first |
| 87 | // step to quickly guess a supported file format. |
| 88 | std::vector<std::string> SupportedExtensions(); |
| 89 | |
| 90 | } // namespace piex |
| 91 | |
| 92 | #endif // PIEX_PIEX_H_ |