Analyze the reason why the calculation result of the erdas modeling tool is white.
By viewing the calculation process and calculation results of the modeling tool, analyze the specific reasons for this phenomenon, and there are several possible reasons.
First: The calculation result is wrong. The pixel values of the layer obtained by the settlement are all zero. You can use the crosshair tool in the image display window to click on the image to view the pixel values, or you can view the pixel values through the INFO button tool panel. In this case, the image is all displayed in white after being stretched and displayed by the software.
Second: The data format is wrong in the calculation process. For example, the calculated pixel values may be above 300, but if the output result data type adopts the 8bit data format, the calculated results will automatically be collected as 255, which is the 8bit maximum value. At this time, the calculated layer will also be displayed in white.
Third: The calculated result is basically correct, but due to some abnormal values in the layer, the image is stretched to white when displayed. For example, to calculate the normalized vegetation index (NDVI), the index value range is between (-1-1), if there is a value above 255, for example, the background is 255, then the entire image will be stretched to white. To display normally, you need to change the stretching method. Both erdas software and arcgis software can change different stretching methods.