三恩時枯葉測試灰卡降噪中低對比度噪點測試

YE0265枯葉目標用于分析“紋理損失"，這是由于降噪或其他圖像處理技術(shù)導(dǎo)致的圖像中低對比度，精細細節(jié)的損失。

YE0265包括四個項目：

•背景

所有以下項目放在中性灰色背景上，灰度為18％

•注冊標記

在測試圖上放置四個對準標記，每個角上一個。這些標記用于分析軟件中的自動注冊，例如。圖像工程iQ分析器

•灰色補丁

圖卡包含16個灰色補丁。 這些補丁的反射在最亮補丁和最暗補丁之間是線性間隔的。

•枯葉模式

主要項目是所謂的死樹葉模式。該圖案由彼此堆疊的圓圈組成，具有已知的位置，半徑和灰度級分布。灰度級限于最大可實現(xiàn)對比度的80％的最大對比度。 

推薦用法：

我們建議以這種方式使用被測設(shè)備再現(xiàn)圖表，圖卡填充不超過圖像高度的1/3。

如果此圖卡填充1/3的圖像高度，它可以用于攝像機的采樣率高達30萬像素。 

枯葉模式及其屬性在本文中描述：

“閉塞模型自然意象：一個尺度不變枯葉模型的統(tǒng)計研究"

由李安，戴維·芒福德和競崗黃，國際計算機視覺41（1/2），35-59，2001

對于圖像的基于軟件的分析，捕獲的YE0265，你可以使用圖像工程IQ-分析第5版和更新。該軟件將提供衡量這個目標的空間頻率響應(yīng)（SFR）。

The YE0265 Dead Leaves Target is used for the analysis of 'texture loss', which is the loss of low contrast, fine details in images due to noise reduction or other image processing techniques. 

The YE0265 consists of four items: 

• Background

All following items are placed on a neutral gray background with a gray level of 18% 

• Registration marks

Four registration marks are placed on the test chart, one in each corner. These marks are used for the automatic registration in analysis software, e.g. the Image Engineering iQ-Analyzer 

• Gray patches

The chart contains 16 gray patches. The reflection of these patches is linear spaced between the brightest patch and the darkest patch. 

• Dead Leaves Pattern

The main item is the so called Dead Leaves pattern. This pattern consists of circles stacked on top of each other with a known distribution of position, radius and gray level. The gray levels are limited to a maximum contrast of 80% of the maximum achievable contrast. 

Recommended usage: 

We recommend to reproduce the chart with the device under test in that way, that the chart fills not more than 1/3 of the image height. 

In case this chart fills 1/3 of the image height it can be used for cameras with a sampling rate of up to 30 Megapixels. 

The Dead Leaves pattern and its properties are described in this paper: 

"Occlusion Models for Natural Images: A Statistical Study of a Scale-Invariant Dead Leaves Model" 

by Ann Lee, David Mumford, and Jinggang Huang , International Journal of Computer Vision 41(1/2), 35-59, 2001 

For the software based analysis of images, captured of the YE0265, you can use the Image Engineering iQ-Analyzer Version 5 and newer. This software will provide the Spatial Frequency Response (SFR) measured on this target.

三恩時枯葉測試灰卡降噪中低對比度噪點測試