Assuming you have a TImage on the form called Image1: procedure LoadImageFromStream(Stream: TStream Image: TImage) It is capable of detecting the image type from a stream.
Graphic file converter png to jpg windows#
However, in XE2, there is another class in Vcl.Graphics called TWICImage that handles images supported by the Microsoft Imaging Component, including BMP, GIF, ICO, JPEG, PNG, TIF and Windows Media Photo. I don't have Delphi 2007 or 2009 to see if this will work in either of those versions. Maybe you can use this library for your purpose. This seems very similar to the VB6 way of doing this that you mention. The GraphicEx library has an example convert that uses GraphicClass := FileFormatList.GraphicFromContent(.) TBitmap, TJPEGImage, TGIFImage, TPngImage) įileStr := TFileStream.Create('D:\Temp\img.dat', fmOpenRead) įor ClassIndex := Low(GraphicClasses) to High(GraphicClasses) do begin GraphicClasses: array of TGraphicClass = ( You could use the efg page as a starting point of your research.Ī quick and dirty solution is to try the few formats you need to handle until one succeeds: function TryLoadPicture(const AFileName: string APicture: TPicture): boolean There's a reason that there is no matching TPicture.LoadFromStream method.Īn external library which can examine data and determine the graphic format at runtime would be the best solution. You can't use TPicture.LoadFromFile if you don't know what format the graphic has, as this method uses the file extension to determine which of the registered graphic formats needs to be loaded. If Copy(FirstBytes, 1, 2) = #$FF#$D8 then procedure DetectImage(const InputFileName: string BM: TBitmap) įS := TFileStream.Create(InputFileName, fmOpenRead) If the file extension is not known one method is to look at the first few bytes to determine the image type. Picture.LoadFromFile('C:\imagedata.dat') ī(0, 0, Picture.Graphic) Procedure TForm1.Button1Click(Sender: TObject) If the file has an extension you can use the following code, as noted by others the TPicture.LoadFromFile looks at the extensions registered by the inherited classes to determine which image to load. Most image capture devices (such as digital cameras) that output JPG creates files in the Exif format, the camera industry standardized for metadata interchange.Īdobe Photoshop, Paint Shop Pro, the GIMP, GraphicConverter, Helicon Filter, ImageMagick, Inkscape, IrfanView, Pixel image editor, Paint.NET, Xara Photo & Graphic Designer.Īpple Safari, Google Chrome, Mozilla Firefox, Internet Explorer, Adobe Photoshop, Paint Shop Pro, the GIMP, ImageMagick, IrfanView, Pixel image editor, Paint.NET, Xara Photo & Graphic Designer.Delphi 2009 comes with built in support for JPEG, BMP, GIF and PNG.įor earlier versions of Delphi you may need to find third party implementations for PNG and GIF, but in Delphi 2009 you simply add the Jpeg, pngimage and GIFImg units to your uses clause. Image files that employ JPG compression are commonly called "JPG files" and are stored in variants of the JIF image format. However, PNG was designed for transferring images on the Internet, not for professional-quality print graphics, and therefore does not support non-RGB color spaces such as CMYK. PNG supports palette-based images (with palettes of 24-bit RGB or 32-bit RGBA colors), grayscale images (with or without alpha channel), and full-color non-palette-based RGB images (with or without alpha channel). JPG typically achieves 10:1 compression with little perceptible loss in image quality. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPG is a commonly used method of lossy compression for digital images, particularly those produced by digital photography. However, PNG itself does not support animation at all. PNG was created as an improved, non-patented replacement for Graphics Interchange Format (GIF) and is the most used lossless image compression format on the Internet. Portable Network Graphics (PNG) is a raster graphics file format that supports lossless data compression.