Question

我正在jsf应用程序中使用Primefaces（V6.2）photocam组件捕获要在tessaract api中处理的图像。

我使用了https://www.primefaces.org/showcase/ui/multimedia/photoCam.xhtml中的示例代码。到目前为止，代码在便携式计算机和android智能手机（chrome + Firefox）上都可以正常工作，并且我能够以所需的分辨率捕获图像。

问题：在Safari浏览器的IOS设备中打开应用程序时，我可以访问相机并捕获图像，但是系统中存储的图像是纯黑色或纯白色。根据图像分辨率，图像的大小从2KB到60KB不等。

我使用了来自github https://github.com/jhuckaby/webcamjs的最新webcam.js来避免在较旧版本的webcam.js上运行的primefaces 6.2版本中已知的网络摄像头加载问题。

xhtml

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:p="http://primefaces.org/ui"
    xmlns:fn="http://java.sun.com/jsp/jstl/functions">
<f:view locale="#{bean.locale}">
    <h:head>
        <title>sample</title>
        <h:outputScript library="#{application.resourceid}" name="js/webcam.js" />
<script type="text/javascript">

function setparams(){
    var isMobile = false; //initiate as false
    // device detection
    if(/(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|ipad|iris|kindle|Android|Silk|lge |maemo|midp|mmp|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows (ce|phone)|xda|xiino/i.test(navigator.userAgent) 
        || /1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test(navigator.userAgent.substr(0,4))) { 
        isMobile = true;
    }
    Webcam.set({
        // live preview size
        width: 320,
        height: 240,
        // Final output size of captured image
        dest_width: 1280, 
        dest_height: 720, 
        // final cropped size
        crop_width: 1280,
        crop_height: 720,

    });
    if(isMobile){
        Webcam.set({
            constraints: {
                facingMode: { exact: 'environment' } // to force chrome to load the Rear camera instead of default front camera
                }   
        });     
    }
}
$(document).ready(function() {
    setparams();
});
</script>
    </h:head>
    <h:body id="body">
        <h:form>
            <h:panelGrid columns="3" cellpadding="5">
                <p:photoCam widgetVar="pc" listener="#{document.oncapture}"
                    update="photo" />
                <p:commandButton type="button" value="Capture" onclick="PF('pc').capture()" />
                <p:outputPanel id="photo">
                    <p:graphicImage name="#{document.imgsrc}"  rendered="#{not empty document.imgsrc}" />
                </p:outputPanel>
            </h:panelGrid>
        </h:form>
    </h:body>
</f:view>
</html>

方法

@ManagedBean(name = "document")
@ViewScoped
public class PhotoCamView {

    private String filename;
    private String imgsrc;

    public String getImgsrc() {
        return imgsrc;
    }

    public void setImgsrc(String imgsrc) {
        this.imgsrc = imgsrc;
    }

    private String getRandomImageName() {
        int i = (int) (Math.random() * 10000000);

        return String.valueOf(i);
    }

    public String getFilename() {
        return filename;
    }

   public void oncapture(CaptureEvent captureEvent) {
        filename = getRandomImageName();
        byte[] data = captureEvent.getData();
        ExternalContext externalContext = FacesContext.getCurrentInstance().getExternalContext();
        String newFileName = externalContext.getRealPath("") + File.separator + "resources" + File.separator + "demo" +
                File.separator + "images" + File.separator + "photocam" + File.separator + filename + ".jpeg";
        // This path is used to render the captured image in page
        imgsrc =  "demo" +  File.separator + "images" + File.separator + "photocam" + File.separator + filename + ".jpeg"; 
        FileImageOutputStream imageOutput;
        try {
            imageOutput = new FileImageOutputStream(new File(newFileName));
            imageOutput.write(data, 0, data.length);
            imageOutput.close();
        }
        catch(IOException e) {
            LOGGER.trace("Error in writing captured image.", e);
        }
    }
}

试图识别代码出了什么问题。我也尝试通过删除setparams（）javascript方法来加载IOS设备。但是什么都没有解决。

Primefaces Photocam-在野生动物园浏览器中捕获图像的问题

0 个答案: