Legacy ImageMagick Discussions Archive

• * Format conversion: convert an image from one format to another (e.g. PNG to JPEG)
  * Transform: resize, rotate, crop, flip or trim an image
  * Transparency: render portions of an image invisible
  * Draw: add shapes or text to an image
  * Decorate: add a border or frame to an image
  * Special effects: blur, sharpen, threshold, or tint an image
  * Animation: create a GIF animation sequence from a group of images
  * Text & comments: insert descriptive or artistic text in an image
  * Image identification: describe the format and properties of an image
  * Composite: overlap one image over another
  * Montage: juxtapose image thumbnails on an image canvas
  * Motion picture support: read and write the common image formats used in digital film work
  * Image calculator: apply a mathematical expression to an image or image channels
  * High dynamic-range images: accurately represent the wide range of intensity levels found in real scenes ranging from the brightest direct sunlight to the deepest darkest shadows.
  * Large image support: read, process, or write mega- and giga-pixel image sizes
  * Threads of execution support: ImageMagick is thread safe and many internal algorithms are already threaded to take advantage of speed-ups offered by the dual and quad-core processor technologies.

2007-09-29  6.3.6-0 Anthony <anthony@griffith...>
  * Added Scaling 'derivitives' to -distort Arc, so image arcing is now
    sharp and clear as you approach the center of the distort.
  * Added  " -set option:distort:viewport 'geometry' " special option
    that can be used to override the output image size and offset.
  * Fixed experimental use of -filter and -support in Resampling (more later).
  * Changed order for coordinate arguments in -distort (for leastsq addition)

2007-09-22  6.3.6-0 Cristy  <quetzlzacatenango@image...>
  * Check the API version and quantum depth before loading a coder module or
    image filter (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=9780).
  * Add exception to the image filter signature.
  * Get the execution path under Mac OS X.
  * TIFFTAG_STRIPBYTECOUNTS requires a uint32 pointer (magick/compress.c).
  * Fixed memory leak in CloneString() (reference
    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=9763).
  * Set S_IRUSR | S_IWUSR | S_IRGRP mode when writing a file in
    CopyDelegateFile().

u1,v1 u2,v2 u3,v3 u4,v4 x1,y1 x2,y2 x3,y3 x4,y4

u1,v1 x1,y1 u2,v2 x2,y2 u3,v3 x3,y3 u4,v4 x4,y4 ...

• It links src and destination coordinates that refer to each other, more directly which makes it a lot easier when editing and adjusting the coordinates.
• Coordinates could also then come from a text file mapping of one coordinate change per line (this still needs testing but should be working).
• Second it means you can think of the coordinates as any point, not just a corner of a triangle or quadrilateral.
• The main reason however... You can use a larger list of automatically determined points (from an image registration program), of say 20 or more coordinates, rather than the minimum.
• This is not just not just for perspective but for even higher level polynomial distortions of coordinates, such as barrel/pincussion distortions (corrections), and possibly future spline or triangular mesh warps (think movie transformations!)
• More points of registration also allows your to more exactly define the distortion beyond normal pixel resolution, and the future possibility for IM to automatically finding deleting 'large error' coordinates (with user control of course).
• Finally the current (old) method was just something that seemed to be good format style when I was first proto-typing the perspective transform using -fx. It was never really thought out very well.