GPUImage将图像大小加倍 - iOS / Swift

Question

我正在尝试使用GPUImage将图像转换为灰度图像。我写了一个扩展来完成我的工作。灰度的东西还可以。但输出图像的尺寸增加了一倍。在我的情况下，我需要图像的大小。有人可以帮我这个吗？任何帮助将受到高度赞赏。

这是我写的扩展

import UIKit
import GPUImage

extension UIImage {

    public func grayscale() -> UIImage?{

        var processedImage = self

        print("1: "+"\(processedImage.size)")

        let image = GPUImagePicture(image: processedImage)

        let grayFilter = GPUImageGrayscaleFilter()
        image?.addTarget(grayFilter)

        grayFilter.useNextFrameForImageCapture()
        image?.processImage()
        processedImage = grayFilter.imageFromCurrentFramebuffer()

        print("2: "+"\(processedImage.size)")

        return processedImage
    }

}

这是控制台中的输出

编辑：我知道稍后可以调整图片大小。但需要知道为什么会发生这种情况，并且有什么办法可以保持图像大小，就像使用GPUImage一样。

Answer 1

尝试稍后缩放图像：

if let cgImage = processedImage.cgImage {
     //The scale value 2.0 here should be replaced by the original image's scale. 
     let scaledImage = UIImage(cgImage: cgImage, scale: 2.0, orientation: processedImage.imageOrientation)
     return scaledImage
}

Answer 2

我不知道@Configuration @EnableTransactionManagement(proxyTargetClass = true) @EnableJpaRepositories(basePackages = {"com.arcvideo.cloudagent.repo", "com.arcvideo.cloudagent.customer"}) @PropertySource("classpath:database.properties") public class DatabaseConfig { @Autowired private Environment env; @Bean(destroyMethod = "close") DataSource dataSource() { HikariConfig dataSourceConfig = new HikariConfig(); dataSourceConfig.setPoolName("springHikariCP"); dataSourceConfig.setConnectionTestQuery("SELECT 1"); dataSourceConfig.setDataSourceClassName(env.getProperty("hibernate.connection.driver_class")); Properties dataSourceProperties = new Properties(); dataSourceProperties.put("url", env.getProperty("hibernate.connection.url")); dataSourceProperties.put("user", env.getProperty("hibernate.connection.username")); dataSourceProperties.put("password", env.getProperty("hibernate.connection.password")); dataSourceConfig.setDataSourceProperties(dataSourceProperties); return new HikariDataSource(dataSourceConfig); } @Bean public LocalContainerEntityManagerFactoryBean entityManagerFactory() { LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean(); entityManagerFactory.setDataSource(dataSource()); entityManagerFactory.setPackagesToScan(env.getProperty("entitymanager.packagesToScan")); HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter(); entityManagerFactory.setJpaVendorAdapter(vendorAdapter); Properties additionalProperties = new Properties(); additionalProperties.put("hibernate.dialect", env.getProperty("hibernate.dialect")); additionalProperties.put("hibernate.cache.use_query_cache", env.getProperty("hibernate.cache.use_query_cache")); additionalProperties.put("hibernate.cache.use_second_level_cache", env.getProperty("hibernate.cache.use_second_level_cache")); additionalProperties.put("hibernate.cache.region.factory_class", env.getProperty("hibernate.cache.region.factory_class")); additionalProperties.put("hibernate.autoReconnect", env.getProperty("hibernate.autoReconnect")); additionalProperties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto")); additionalProperties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql")); additionalProperties.put("hibernate.format_sql", env.getProperty("hibernate.format_sql")); additionalProperties.put("javax.persistence.sharedCache.mode", env.getProperty("javax.persistence.sharedCache.mode")); additionalProperties.put("hibernate.generate_statistics", env.getProperty("hibernate.generate_statistics")); entityManagerFactory.setJpaProperties(additionalProperties); return entityManagerFactory; } } 库如何将图像转换为灰度图像。我猜测他们的实现会扩大图像范围。您可以自己缩小它，或者我建议您使用以下代码将图像转换为灰度

GPUImage

来源：https://stackoverflow.com/a/40181589/7842542