Jpg to png in cpp

[Solved]-How do you convert a .jpg to .png in C++ on Windows 8?-C++

I’m not familiar with Windows-8 programming, but just looking at the docs, isn’t that as simple as this?

Stream imageStreamSource = new FileStream("myimage.jpg" . ); JpegBitmapDecoder decoder = new JpegBitmapDecoder(imageStreamSource, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default); BitmapSource bitmapSource = decoder.Frames[0]; FileStream stream = new FileStream("myimage.png", FileMode.Create); PngBitmapEncoder encoder = new PngBitmapEncoder(); encoder.Interlace = PngInterlaceOption.Off; encoder.Frames.Add(bitmapSource); encoder.Save(stream); 

BitmapDecoder::GetPixelDataAsync(BitmapPixelFormat, BitmapAlphaMode, BitmapTransform, ExifOrientationMode, ColorManagementMode) 

BitmapEncoder::SetPixelData(BitmapPixelFormat pixelFormat, BitmapAlphaMode alphaMode, unsigned int width, unsigned int height, double dpiX, double dpiY, array^ pixels) 

How about using the ImageMagick library?

Theres a C++ API . inthe documentation I found this in a 2 minute search:

#include using namespace std; using namespace Magick; int main(int argc,char **argv) < InitializeMagick(*argv); // Read GIF file from disk Image image( "giraffe.gif" ); // Write to BLOB in JPEG format Blob blob; image.magick( "JPEG" ) // Set JPEG output format image.write( &blob ); [ Use BLOB data (in JPEG format) here ] return 0; >

Personally, I can recommend this library having worked rather extensively with ImageMagick (although with the C API. )

Edit: You can write the image to a memory blob and pass the bytes to the encoder.

You can read the pixel data and write them to a BitmapEncoder using a given image format (codec) like this (sorry, that’s C# and not C++, but it should work):

const string sourceFileName = "42.jpg"; StorageFolder imageFolder = Package.Current.InstalledLocation; StorageFile imageFile = await imageFolder.GetFileAsync(sourceFileName); using (IRandomAccessStream imageStream = await imageFile.OpenReadAsync()) < // Read the pixel data BitmapDecoder bitmapDecoder = await BitmapDecoder.CreateAsync(imageStream); BitmapTransform dummyTransform = new BitmapTransform(); PixelDataProvider pixelDataProvider = await bitmapDecoder.GetPixelDataAsync( BitmapPixelFormat.Rgba8, BitmapAlphaMode.Ignore, dummyTransform, ExifOrientationMode.RespectExifOrientation, ColorManagementMode.ColorManageToSRgb); byte[] pixelData = pixelDataProvider.DetachPixelData(); // Save the pixel data as PNG const string resultImageFileName = "42.png"; StorageFile resultImageFile = await ApplicationData.Current.LocalFolder.CreateFileAsync( resultImageFileName, CreationCollisionOption.ReplaceExisting); using (IRandomAccessStream resultImageStream = await resultImageFile.OpenAsync(FileAccessMode.ReadWrite)) < BitmapEncoder bitmapEncoder = await BitmapEncoder.CreateAsync( BitmapEncoder.PngEncoderId, resultImageStream); bitmapEncoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Ignore, bitmapDecoder.OrientedPixelWidth, bitmapDecoder.OrientedPixelHeight, 96, 96, pixelData); await bitmapEncoder.FlushAsync(); >> 

The only question is how to determine the best settings for the pixel format, alpha mode and DPI regarding the file format (in this case PNG). I determined the pixel mode from an existing PNG file. BitmapAlphaMode.Ignore is set because JPEG does not support transparency. Therefore it would not make sense to enable the alpha channel in the PNG file. Width and height are set to OrientedPixelWidth and OrientedPixelHeight of the BitmapDecoder because I enabled EXIF orientation when reading. DPI is set best regarding the target system. 96 is default for Windows.

Related Query

• How do you convert a .jpg to .png in C++ on Windows 8?
• How do you convert CString and std::string std::wstring to each other?
• How you convert a std::string_view to a const char*?
• How do you debug a Windows Service?
• How do you convert a C++ string to an int?
• How do you programmatically determine whether a Windows computer is a member of a domain?
• How to get a python .pyd for Windows from c/c++ source code? (update: brisk now in Python in case that’s what you want)
• How do you convert a Visual Studio project from using wide strings to ordinary strings
• How would you convert a std::string to BSTR*?
• How can you get the return value of a Windows thread?
• How do you convert a string to ascii to binary in C#?
• How do you compile WebkitGTK on windows for MinGW
• How do you convert LPCWSTR to const char *?
• How do you identify exported functions in a Windows static library?
• how do you connect to a Wireless WIFI Network in QT or windows API?
• How do you access a Metro app’s local storage in a desktop application in Windows 8?
• How do you convert a 16 bit unsigned integer to a larger 8 bit unsigned integer?
• How do you convert a C++ object to a PyObject?
• How do you read the console output from windows commands in C++?
• How to save a pcl::Histogram to PNG or JPG file?
• How do you convert UINT8 to UINT32 in C++?
• How do you convert an int into a string in c++
• How do you convert a string into an array of floats?
• How to convert a text file from Windows to Unix
• How to reliably convert local time to UTC on a Windows machine using C++ WinAPI
• How do you get the current sample rate of Windows audio playback?
• How do you convert from shared_ptr to shared_ptr when returning from a function?
• C++: How do you convert the name of a function pointer to text?
• How do you convert a lvalue to an rvalue? And what happens to the `new` lvalue?
• How do I get conversion with «OverflowError: Python int too large to convert to C long» error working on Windows Server 2012?

More Query from same tag

• Initial directory is not working for CFileDialog
• How to install Visual Studio Build Tools 2010 on Visual Studio 2015 Community?
• remove an item from a vector of std::function
• C++ sizeof Vector is 24?
• Qt instant object intercommunication in GUI
• method of getting valid fullscreen resolutions on OS X in Objective-C or C++?
• Truncate float so as to have only two decimals
• What requirements are necessary and sufficient for an ActiveX control to be used directly on an Excel worksheet?
• Correct behavior using virtual methods
• When have you used C++ ‘mutable’ keyword?
• Working around limitation of `constexpr` static data member with same type as enclosing class
• Boost::Asio Multicast listen address
• Handling overflow when casting doubles to integers in C
• C++ code run very slow in a predominantly Objective-c project
• How do you find the least optimized parts of a program?
• No viable overloaded operator for references a map
• How to use to replace rand()?
• Using decltype to return iterator
• What does SHIMVIEW: shiminfo means?
• C++ DateTime class
• C++ program crashes down
• concatenate char with int
• Is there anyway to store key, value, value into map
• How to make C++ code faster: Creating .csv file from camera data using CFile
• Debugging strategy to find the cause of bad_alloc
• What is the difference between delete and calling destructor in C++
• Friend function and templates
• How to use GLEW with Qt?
• How should roulette wheel selection be organized for non-sorted population in genetic algorithm?
• Undefined reference for ~queue with explicit template instantiation with Clang 10

Источник

Convert JPG to PNG in C++

High-speed and cross-platform C++ Library that helps in developing applications with the ability to create, merge, inspect, or convert Microsoft PowerPoint and OpenOffice presentation files without the use of any software like Microsoft or Open Office, Adobe PDF.

Convert JPG to PNG in C++

Aspose.Slides for C++ is a powerful C++ library for creating and manipulating presentation files. Moreover, it provides flexible ways to convert JPG to PNG. Using Aspose.Slides for C++, any developer or application can convert JPG to PNG files with just a few lines of C++ code.

As a modern document processing API, Aspose.Slides for C++ exports JPG files to PNG file formats quickly. Aspose PowerPoint library allows you to convert JPG to PNGs and many other file formats

Convert JPG to PNG using C++

To convert the JPG to PNG, you will need to create Presentation from JPG file and save it as PNG.

C++ code for converting JPG into PNG

 auto pres = System::MakeObjectPresentation>(); auto slide = pres->get_Slides()->idx_get(0); auto image = pres->get_Images()->AddImage(File::ReadAllBytes(u"image.jpg")); slide->get_Shapes()->AddPictureFrame(ShapeType::Rectangle, 10.0f, 10.0f, 100.0f, 100.0f, image); for (int32_t i = 0; i  pres->get_Slides()->get_Count(); i++)   // Control hidden slides (do not render hidden slides)  if (pres->get_Slides()->idx_get(i)->get_Hidden())    continue;  >   // Convert slide to a Bitmap object  System::SharedPtrBitmap> bmp = pres->get_Slides()->idx_get(i)->GetThumbnail(2.f, 2.f);   // Create file name for an image  System::String outputFilePath = Path::Combine(outputDir, System::String(u"Slide_") + i + u".png");   // Save the image in PNG format  bmp->Save(outputFilePath, ImageFormat::get_Png()); > 

Источник

Convert multiple JPG to PNG in C++

High-speed C++ library to convert several JPG into PNG

Use C++ to obtain maximum JPG into PNG merge speed. This is a professional solution to join several JPG into a single PNG using C++. Try it online for free!

Convert JPG to PNG in C++

Modern C++ library allows C++ developers to convert JPG to PNG image format with a few lines of code. JPG image conversion engine analyses the original graphical content, and exports the combined picture to PNG format.

Use C++ to convert JPG to PNG image format with maximum flexibility and speed. Run online live demo and check the highest PNG image quality right in a browser. JPG Conversion API supports a bunch of useful options.

Merge JPG to PNG in C++

To convert several JPG to PNG just use C++ library that handles all low-level details.

Convert multiple JPG images and save the result as a single PNG image. If you develop code in C++, image format conversion will be simpler than it sounds. See C++ example that iterates through image files and combines them into PNG:

using namespace Aspose::Words; std::vector fileNames < u"Input1.jpg", u"Input2.jpg" >; auto doc = MakeObject(); auto builder = MakeObject(doc); std::vector> shapes; for (const auto& fileName : fileNames) < auto shape = builder->InsertImage(fileName); shapes.push_back(shape); > // Calculate the maximum width and height and update page settings // to crop the document to fit the size of the pictures. auto maxWidth = *std::max_element(shapes.begin(), shapes.end(), [](auto lhs, auto rhs) return lhs->get_Width() < rhs->get_Width(); ); double maxHeight = std::accumulate(shapes.begin(), shapes.end(), 1.0, [](double result, auto shape) return result + shape->get_Height(); ); auto pageSetup = builder->get_PageSetup(); pageSetup->set_PageWidth(maxWidth->get_Width()); pageSetup->set_PageHeight(maxHeight); pageSetup->set_TopMargin(0); pageSetup->set_LeftMargin(0); pageSetup->set_BottomMargin(0); pageSetup->set_RightMargin(0); doc->Save(u"Output.png"); 

How to convert several JPG into PNG

1. Install ‘Aspose.Words for C++’.
2. Add a library reference (import the library) to your C++ project.
3. Open the source JPG file in C++.
4. Convert several JPG files into PNG in a few seconds.
5. Call the ‘AppendDocument()’ method, passing an output filename with PNG extension.
6. Get the result of conversion JPG into PNG.

C++ library to convert several JPG into PNG

There are three options to install Aspose.Words for C++ to your developer environment. Please choose one that resembles your needs and follow the step-by-step instructions:

• Install a NuGet Package. See Documentation
• Install the library using Package Manager Console within Visual Studio IDE
• Install the library manually using Windows Installer

System Requirements

You can use this C++ library to develop software on Microsoft Windows, Linux and macOS operating systems:

• GCC >= 6.3.0 and Clang >= 3.9.1 are required for Linux
• Xcode >= 12.5.1, Clang and libc++ are required for macOS

If you develop software for Linux or macOS, please check information on additional library dependencies (fontconfig and mesa-glu open-source packages) in Product Documentation.

Other Supported JPG Merge operations

You can merge JPG to many other file formats:

Источник