January 30, 2013
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用jPodRenderer 轉PDF做jpg / png
遇到個問題...如果個PDF係全image, 即係無字果D
轉出黎個色可能會反轉左...試左轉幾個白底黑字既pdf出黎變左黑底白字研究左好耐...究竟係邊度出問題呢？點解text唔會有呢個問題...Apache PDFBox又唔會有呢個問題？
猛咁google "pdf image inverted color"...呢D都唔係keyword...搵搵下入左Adobe official
雖然而家未有方法驗証到，後黎比我搵到個好可能既答案就係pdf object既color model
係CMYK定係RGB...
唉無讀過multimedia / computer graphic既我係咁上下架喇
今日要留到到RGB係additive, CMYK係subtractive
所以RGB = #000果陣係黑色, 但CMYK全0果陣係白色唔知點解Java內置既BufferedImage class只support RGB
如果擺左幅CMYK既野入去就會出事
問題係我點知個pdf既color mode係咩呢？要用Acrobat Professional先check到...本公司用既唔係Pro版所以check唔到=.=...開埋jPodRenderer既source code黎睇
明明佢有埋method叫做readAnyJPEGSource...有咩algorithm將CMYK轉做RGB
但係detect pdf object係咩color mode果陣...竟然寫埋comment "hope this condition is enough to filter out all CMYK objects"之類
即係話連寫code果個都唔係好知點100% detect個color mode唔...但係用Apache PDFBox又有個問題，就係睇唔到Embedded Fonts...咁點好呢
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臨收工前
「west呀！你知唔知Tomcat點做clustering架？」
嘩我真係唔知Tomcat可以做clustering架wor...=======
呢排睇太多經濟日報
仲要focus起財經地產版
睇到...連思想都傾斜去金融世界...
唔係一個好現象
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