Abstract

Nowadays user devices such as phones, tablets etc. allows processing the images with help of high-end applications and softwares developed. Most of the times, the images are downscaled to make them compatible with these end devices. This leads to the loss of image quality. This loss of information on downscaling an image results in distortion of edges and while zoomed in results into a blurred image. As the edge detection is a basic step for many image processing applications such as object detection, object segmentation, object recognition, etc. It is necessary to know the impact of edge detection on downscaled image. In this paper, we are using Canny Edge detection method to detect the edges. The original images are downscaled using different interpolation methods. Canny Edge detection is applied on original images and downscaled images to compare the distortion in the edges. We used Structural Similarity Index Method for comparison. We are also comparing execution time taken by Canny Edge Detection on different interpolation methods to check for optimal interpolation method. We observed that the distortion in edges and time efficiency differ for different interpolation methods which are detailed below in the result section. As blurring is also a disadvantage of downscaling, we are applying Gaussian Blur on the images to compare the blurring due to Gaussian blur technique and blurring due to downscaling.

中文翻译：

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Canny边缘检测对缩小图像的影响研究

摘要

如今，用户设备（例如电话，平板电脑等）可以借助高端应用程序和开发的软件来处理图像。在大多数情况下，图像会按比例缩小以使其与这些终端设备兼容。这导致图像质量的损失。关于缩小图像的信息丢失会导致边缘变形，而放大则会导致图像模糊。由于边缘检测是许多图像处理应用程序（如对象检测，对象分割，对象识别等）的基本步骤。因此有必要了解边缘检测对缩小图像的影响。在本文中，我们使用Canny Edge检测方法来检测边缘。使用不同的插值方法将原始图像按比例缩小。Canny Edge检测应用于原始图像和缩小后的图像，以比较边缘的失真。我们使用结构相似指数法进行比较。我们还将比较Canny Edge Detection在不同插值方法上花费的执行时间，以检查最佳插值方法。我们观察到边缘的失真和时间效率对于不同的插值方法是不同的，下面将在结果部分中详细介绍。由于模糊也是缩小比例的缺点，因此我们在图像上应用高斯模糊，以比较由于高斯模糊技术而导致的模糊和因缩小而导致的模糊。我们还将比较Canny Edge Detection在不同插值方法上花费的执行时间，以检查最佳插值方法。我们观察到边缘的失真和时间效率对于不同的插值方法是不同的，下面将在结果部分中详细介绍。由于模糊也是缩小比例的缺点，因此我们在图像上应用高斯模糊，以比较由于高斯模糊技术和缩小而导致的模糊。我们还将比较Canny Edge Detection在不同插值方法上花费的执行时间，以检查最佳插值方法。我们观察到边缘的失真和时间效率对于不同的插值方法是不同的，下面将在结果部分中详细介绍。由于模糊也是缩小比例的缺点，因此我们在图像上应用高斯模糊，以比较由于高斯模糊技术和缩小而导致的模糊。