Can you please explain the difference between regular R - G- B streams and Temp Img, Temp Rimg (etc) streams? What are the reasons one might want to use a Temp img or TempR(G,B)img streams? What do they do differently? Also if you get some time can you explain Float Img streams a little bit?
Temp Img is the same as Temp (R,G,B) Img, they are all 1 channel image buffers. The labeling is different, that's all. The ones with the r,g,b labeling are useful if you need a 3 channel image buffer to store an r,g,b image as a part of the procssing chain. By using the 3 streams named temp img r,g,b you can keep track of which is which.
A normal image buffer is stored as a short integer in MSG (16 bits). This gives you more bit depth than 8 bits per channel. The output image is truncated to 8 bits for display and output. The higher internal precision allows for processing without clipping. Version 4 also allows for a new preference option that lets you really stretch out the computation range in 16 bits for improved visual quality.
Float Img streams are 32 bits per pixel. Some msg processors like FSA and Chamfer map processors output Float Img's. These float images are not normal image buffers, they are special buffers that allow for fast computations in the overall signal processing chain associated with this kind of image processing. Then there are other associated processors that take that special float buffer output and convert it back into normal images.
So this kind of image processing takes a normal image channel, processes it to a special float image buffer, and then another processor finishes the overall processing by taking that float buffer and converting it back to a normal image buffer. By having the different components and intermediate buffers be split out rather than integrated, when you run evolution or mutation on the msg preset different start and end processors can be randomly inserted or mutated, leading to a wide range of visual effects.
FSA processing allows for resolution independent image processing with constant time processing speed. You can think of chamfer map processing as computing a distance map between shapes in an image.
Again, there's really no real difference between the various temp img streams, they are just individual single channel image buffers that are named differently so that you can better keep track of what is going on in your stream io connections.
The best way to understand the float stream is to look at msg presets that use them. Choose some generic msg preset in evolver and then run the configuration : add metaeffect at end : stylistic : 3D lighting effect menu. Look at the processor chain editor before and after running this meta edit. A float image stream is added automatically, and msg processors are hooked up as i described above that use the float image stream.
Here's a little more info on MSG Stream Sources below. Color images are always represented as 3 different RGB channel images in MSG. Note that the effect output can also have an alpha channel in addition to the R,G,B channels that make up the color image.
Note that some streams, like the source, the output, the color gradients and palettes are fixed resources, you can't have duplicates. Other streams, like Tmp img are allocated on demand, so you can have as many as you need to route thing in the msg effect. keep in mind that they do take up memory, so having more makes the effect more memory intensive.
R Src, G Src, B Src - red, green, blue channels of the source image for the msg effect
R Out, G Out, B Out - reg, green, blue channels of the output image for the msg effect.
Color Palette, Color Palette 1 - 2 different color palettes
Color Gradient, Color Gradient 1, Color Gradient 2 - 3 different color gradients
Tmp Img - a 1 channel temporary image buffer. you can have as many of these as you want.
Tmp R Img, Tmp G Img, Tmp B Img - 3 different 1 channel temporary image buffers. You can have as many of these as you want.
Float Img - 1 channel temporary floating point image buffer. You can have as many of these as you want.
Alpha Out - 1 channel alpha buffer for the output image for the msg effect.
There are also a few stream types in the Stream Source LIbrary that are experimental or vestigial relics from the past. They include: