It is used to define an external image on any texture channel. These images can be RGB, Alpha or Greyscale. It is an option you will often use during texture creation. You may need to make some adjustments depending on the picture you have selected for efficient use of the GPU and Vram. We will discuss what these settings are in "Image Texture Settings".
how to use
Open the Node editor and prepare the setup as you see in the picture below. In this setup, both greyscale and rgb images are used. It's a standard setup, all you have to do is create the pictures and "Image Texture" nodes you need and connect them to the relevant channels. In the picture below, "real surface displacement textures" are used for image textures that give a rocky-sand view. These textures are very high quality and they are commercial. You can find it online. You can also prepare your own textures in the 3rd party softwares (eg. bitmap2Material). In the example setup, the "transform" node is also attached to all image texture nodes. So you can do all transform operations with a single node for images of the same size and resolution. However, this method may not be suitable for different resolutions.
IMAGE TEXTURE SETTINGS
From here you can define any image texture.
Controls the brightness of the image.
Controls the luminance of the input image.
Inverts the color values of the image.
Sets the behavior of the space around the image if the image does not cover the entire geometry. You can see all the border mode options in the picture below.
From here you can determine the type of your image. Normally, the entire image is converted to RGB values regardless of the image type you upload. For example, if you upload a greyscale image and leave the option here as "Normal", it will still be converted to RGB values. To use the GPU Vram effectively and efficiently, you can set the options here according to the type of your image texture. If you've uploaded greyscale or alpha image, do not forget to choose "Float" or "Alpha" here.
texture Import type
You can look at here
UV TRANSFORM & PROJECTION
USING IMAGE SEQUENCE
You can use the "Image Sequence" texture from the Animation Tab next to the Image texture shader tab. The choices in this tab are based on Cinema 4D. So you can normally use the image sequence as you use in Cinema 4D's Animation tab. The logic is the same. But there are some things you need to be aware of. Now let's look at these.
1. Never use C4d Bitmap, for single-frame or animated, the only option you must use is the native Octane "Image texture".
2. Do not use MP4 and other movie formats. They will not work in Octane anyway. Just use image sequence. Even if you have a movie format, export it as an image sequence and then load into the Octane Image Texture.
3. The most efficient formats for using image sequences are: Tga, Jpeg, Tiff. You can use Png, but Octane is not very efficient in PNG format.
4. When loading a sequence to the image texture channel, load the first frame and enter the frame rate and frame count correctly in the Animation Tab. Unfortunately, C4D's very useful option "Calculate" is not available here. So you have to enter the frame range manually. The other options in this tab is the same of the Cinema 4D's image sequence feature.