gllImage

Picture viewer controls for Delphi VCL, with JPEG XL built in.

• TgllImageView is the stand-alone viewer (the TImage counterpart).
• TgllDBImage is the data-aware one (the TDBImage counterpart; it reads TDBImage's Stretch and Proportional, so a form converts by changing the class name).

Both descend from TgllCustomImageView, so they behave identically:

Formats	JPEG, PNG, BMP, GIF (animated), ICO, WMF, EMF, TIFF (Windows WIC) and JPEG XL (libjxl, through libjxl-delphi); anything else registered with TPicture is tried too.
Viewing	Fit to window, shrink / zoom to fit, zoom (buttons, keys, Ctrl+wheel), pan by dragging, scroll bars, display rotation and flip, checkerboard behind transparency, error state.
Changing	Rotate and flip the picture itself keeping its format (a JPEG XL stays JPEG XL), clipboard, load and save (.jxl included), print, thumbnails.
Drag and drop	Drop files from Explorer and virtual files (an e-mail attachment, an image from a web browser); drag the picture out as a file (EnableDragOut), in its own format.
Data	TgllDBImage stores the bytes of a loaded file exactly as they are, loads asynchronously on request, skips the header old TDBImage controls wrote, and works in a TDBCtrlGrid.

Delphi 13, Win32 and Win64, VCL. The only dependency outside the RTL and VCL is LibJxl, for JPEG XL. High-quality scaling through Skia (RenderMode = rmSkia) is optional: it lives in its own unit and package (gllImage.Skia, gllImageSkiaR), so the core never depends on Skia.

Getting started

1. Build the LibJxl package from libjxl-delphi first: gllImageR requires it. Then build Packages\gllImage.groupproj (runtime gllImageR, the optional Skia renderer gllImageSkiaR, design-time gllImageD, the tests and the demo).
2. Install gllImageD from the 64-bit IDE (bin64\bds.exe). The controls appear on the gllImage palette page.
3. Put jxl.dll beside your executable (libjxl-delphi's CopyJxlDlls.ps1 does it). It is loaded only when a JPEG XL is decoded or encoded.

gllImageView1.FitToWindow := True;
gllImageView1.LoadFromFile( 'C:\Pictures\Photo.jxl' );
gllImageView1.RotatePicture( ro90 );          // the pixels, kept as JPEG XL
gllImageView1.SaveToFile( 'C:\Pictures\Turned.jxl' );

Run Demo\gllImageDemo to see both controls, with two JPEG XL samples.

Documents

• Users Guide.md: how to use the controls, property by property.
• Help.md: building, troubleshooting, and the things that look wrong but are not.
• CHANGELOG.md: what changed and why.

Licence

BSD 3-Clause. libjxl and the libjxl-delphi binding are BSD-3 as well.

Origin

gllImage grew from GDBImage (Sebastián Mayorá's freeware enhanced TDBImage, later Roy Lambert's EDBImage), which lived inside GITLAKDB as TGDBImage until 2026-10-19. A form that still names TGDBImage streams in as TgllDBImage.

How gllImage was developed

gllImage was developed with substantial assistance from an AI coding assistant (Anthropic's Claude), under the maintainer's direction and review. It is tested as described in Help.md.