Efficient defect detection in rail components relies on the meticulous preservation of image details and the augmentation of accuracy. This is achieved through the utilization of a color industrial camera that captures images in RGB format. The initial step involves the conversion of these color images into grayscale for further analysis. Histograms, a prevalent tool in grayscale analysis, play a pivotal role in evaluating factors such as background segmentation, image saturation, and contrast, ensuring alignment with the detection requirements of machine vision systems. LabVIEW's IMAQ Histogram function module is employed in the system to filter out rail component images lacking apparent defects. Workpieces that remain are deemed challenging and proceed to subsequent detection stages for further analysis and processing. Experimental findings show that grayscale values falling within the range of 98-141 correspond to images with minimal to no defects. Statistical data indicate that the pixel count for standard defect-free rail components falls within the range of 35,600 to 38,900 pixels. Within the grayscale range of 98-141, the pixel count is 36,934, indicative of virtually defect-free rail components. The distinct grayscale variations between test workpieces and the background result in discernible peaks in the histogram, facilitating the identification of grayscale values near the valley as the threshold for image segmentation. The incorporation of histograms in the preprocessing of rail component images significantly streamlines subsequent image segmentation processes.