Thumbnail type. Describes how a thumbnail for this image is to be generated.
The following thumbnail types are supported:
Crop the image to the thumbnail aspect ratio. Unless the aspect ratio of the thumbnail rectangle and the image are exactly the same, a part of the image ise cropped to ensure that the entire thumbnail rectangle is filled with image data. The crop rectangle is positioned in the image using attribute::ThumbHorizAlign and attribute::ThumbVertAlign .
Fit the entire image into the thumbnail rectangle. The image is positioned within the thumbnail rectangle using attribute::ThumbHorizAlign and attribute::ThumbVertAlign , and any extra space is filled with attribute::ThumbBkgColor .
Crop the image based on resolution. The image is scaled by ratio of catalog::ThumbRes to catalog::Resolution . If the resulting image is larger than the thumbnail, it is cropped to fit, if the scaled image is smaller than the thumbnail, the remaining area is filled with attribute::ThumbBkgColor . attribute::ThumbHorizAlign and attribute::ThumbVertAlign are used to determine the position of the crop rectangle within a larger image or position of a smaller image within the thumbnail.
Clients request image thumbnails with req=tmb requests.
Enum Value. Valid values are 1, 2, or 3, which corresponds to Crop, Fit, and Texture types, respectively.
attribute::ThumbType is used if the field is not present, if the value is 0 or if the field is empty.