Tuesday, February 19, 2008

Image Viewer and Editor

There are many image viewers for GNUstep. By default, GNUstep supports reading TIFF, GIF, PNG and JPEG formats and writing to TIFF. It also supports image scaling and transformation. So it is relatively easy to write a simple image viewer with GNUstep. Different backends may have slightly different results and performance.

Preview supports these basic built-in functionalities from GNUstep. You can also drag image to move it around if the image is bigger than the window, though for me, it is quite slow if I do that. It is more usable just to drag the scrollbar. It is a document-based application. So you can view multiple images at the same time.

PhotoClip is a single-image viewer and scales the image to fit the window by default. It supports image clipping and rotation by 90, 180 or 270 degree with jpegtran, which comes with libjpeg. You can easily view the previous and next image in the same directory. It is an idea application to go through your photo collection in the same directory, view them, do rotation and clipping, then save them.

PRICE is an image editor with many features. It not only allows you to scale and crop images, but also adjust brightness and contrast, even apply filters, do convolution and Fourier transformation, and trace edge ! While it does not offer preview on some of these filters, it does support undo and redo as a temporary solution. It seems to have issues with image containing alpha layer, but works quite well with the rest. I also have troubles using the convolution, which is the basis of many filters. All these features can be found in manual. Some of these features may require knowledges of image processing, but it is definitely an application with quality and worth to look.

Cenon is a professional application for vector graphics and desktop publishing (DTP). It can import many formats including PDF and Adobe Illustrator, then export to Cenon, EPS, or DXF (Drawing Interchange Format) format. You can have layers, draw shapes and Bezier paths, add text and paragraph, do text on paths, align objects and do transformation, fill objects with colours or gradients, vectorize pixel images, etc. There are so many features that I would suggest you to read the manual first.


You need to download Cenon and CenonLibrary, then follow the INSTALL to install it. It is not updated to use GNUstep Makefiles Package 2.0 yet, so there are some warnings during compilation. I still have some random crashes from time to time, but in general, it is quite pleasant to use. Just remember to save frequently. It also supports multiple undo and redo.

Previous articles in this series:

  • Gomoku and Localization in GNUstep
  • Font Manager and GNUstep Backend
  • System Preferences and Theme
  • Ink, a GNUstep text editor, and Services
  • Addresses, a contact manager
  • StepChat, TalkSoup, and Grouch
  • More on Services

  • 1 comment:

    Riccardo said...

    may you specify what you mean by
    "seems to have issues with image containing alpha layer, but works quite well with the rest. I also have troubles using the convolution, which is the basis of many filters."

    If you could write me with a specific description of each problem, I'd love to solve the issues for the next release. I mailed you privately but you didn't reply. I don't know of issues with the functions you mentioned...