Good and bad classification of apple

Apple Grading Standards

1. Indian Grading Standards (eNAM)

The Electronic National Agriculture Market (eNAM) in India categorizes apples into three primary grades:

Range-I (Superior Quality):

Apples must be of superior quality, characteristic of the variety, and free from defects.

Only very slight superficial defects are permissible, provided they do not affect the general appearance, quality, or presentation.

Range-II (Good Quality):

Apples should be of good quality, characteristic of the variety.

Minor defects in shape, development, coloring, and slight skin or other defects are acceptable, provided they do not affect the overall appearance or quality.

Range-III (Minimum Requirements):

Apples that do not qualify for the higher grades but meet the minimum requirements.

Defects in shape, development, coloring, and skin are permissible, provided the apples retain their essential characteristics regarding quality and presentation.

Minimum Requirements Across All Grades:

Apples must be whole, firm, sound, clean, and free from pests, diseases, and abnormal moisture.

They should have a minimum total soluble solids content of 11° Brix.

Size Classification:

Defect Tolerances:

Russeting outside calyx/stem cavity: up to 1%.

Accumulated blemishes and bruising: not exceeding 1%.

Scab (Venturia inaequalis): not exceeding 0.25 cm² in Class I and 1 cm² in Class II.

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2. United States Grading Standards (USDA)

The United States Department of Agriculture (USDA) defines the following apple grades:

U.S. Extra Fancy:

Apples must be mature but not overripe, clean, well-formed, and free from decay, internal browning, and other specified defects.

They should have the amount of color specified for the variety.

U.S. Fancy:

Similar to Extra Fancy but allows for slight defects, provided they do not detract from the apple's appearance or quality.

U.S. No. 1:

Apples that meet the requirements of U.S. Fancy, except for color, russeting, and invisible water core.

U.S. Utility:

Apples that are mature but not overripe, not seriously deformed, and free from serious damage.

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3. European Union Grading Standards

The European Union classifies apples into three main categories:

Class Extra:

Apples of superior quality, characteristic of the variety, and free from defects, with the exception of very slight superficial defects.

Class I:

Good quality apples, allowing for slight defects in shape, development, coloring, and skin, provided they do not affect the overall appearance or quality.

Class II:

Apples that do not qualify for the higher classes but meet the minimum requirements.

Defects in shape, development, coloring, and skin are permissible, provided the apples retain their essential characteristics.Factors Influencing Apple Quality

1. Physical Attributes

Size and Shape:

Larger apples are generally preferred in markets.

Symmetrical and well-shaped apples are favored for their aesthetic appeal.

苹果分级标准

1. 印度分级标准（eNAM）
印度全国农业电子交易市场（Electronic National Agriculture Market，eNAM）将苹果划分为三大主要等级：

等级I（优等品质）：
苹果需具备对应品种的固有特性，无任何缺陷。仅允许存在极轻微的表面瑕疵，且此类瑕疵不得影响果实的整体外观、品质或商品展示效果。

等级II（良好品质）：
苹果应具备对应品种的良好品质。允许存在形状、发育、着色方面的轻微缺陷，以及表皮或其他轻微瑕疵，前提是此类缺陷不会影响果实的整体外观与品质。

等级III（最低合格要求）：
未达到更高等级标准，但满足最低合格要求的苹果。允许存在形状、发育、着色及表皮方面的缺陷，前提是苹果仍保留其核心品质与商品展示特性。

所有等级通用的最低要求：
苹果须完整、坚实、无损伤、洁净，且无虫害、病害及异常水渍。果实的总可溶性固形物（Total Soluble Solids）含量不得低于11°白利度（°Brix）。

尺寸分级与缺陷容忍度：
- 花萼/果柄腔处的锈斑：占比不超过1%。
- 累计瑕疵与瘀伤总面积：不得超过1%。
- 苹果黑星病（Venturia inaequalis）病斑面积：等级I不超过0.25 cm²，等级II不超过1 cm²。

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2. 美国分级标准（USDA）
美国农业部（United States Department of Agriculture，USDA）制定了以下苹果分级标准：

美国特级（U.S. Extra Fancy）：
苹果须成熟但不过熟，洁净、外形规整，无腐烂、内部褐变及其他规定缺陷。果实应具备对应品种要求的着色程度。

美国优级（U.S. Fancy）：
与特级标准基本一致，但允许存在轻微缺陷，前提是此类缺陷不会降低果实的外观或品质。

美国一级（U.S. No. 1）：
满足美国优级的各项要求，仅在着色、锈斑及隐性水心病（invisible water core）方面可存在例外。

美国实用级（U.S. Utility）：
苹果须成熟但不过熟，无严重畸形，且无严重损伤。

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3. 欧盟分级标准
欧盟将苹果划分为三大主要类别：

特级（Class Extra）：
具备对应品种的优良品质，无任何缺陷，仅允许极轻微的表面瑕疵。

一级（Class I）：
品质良好的苹果，允许存在形状、发育、着色及表皮方面的轻微缺陷，前提是此类缺陷不会影响果实的整体外观与品质。

二级（Class II）：
未达到更高等级标准，但满足最低合格要求的苹果。允许存在形状、发育、着色及表皮方面的缺陷，前提是苹果仍保留其核心品质与商品展示特性。

影响苹果品质的因素
1. 物理属性
尺寸与形状：
市场普遍偏好个头较大的苹果。外形对称规整的苹果因兼具美学吸引力更受青睐。

搜集汇总

背景与挑战

背景概述

该数据集是一个用于苹果质量分类的图像数据集，包含'好'和'坏'两类苹果的图片，总大小为6.15 GB。数据集还提供了印度、美国和欧洲的苹果分级标准，详细描述了各等级的质量要求。