Update: As of version v2019R1, cmykProfile.jar is now packaged inside Qoppa’s library jars and no longer requires to be added to the classpath. When rendering or optimizing images with a CMYK color space (DeviceCMYK), Qoppa’s PDF libraries and components need the cmykProfile.jar to be present in the classpath. If you forget to include this jar, […]
Articles Tagged: image compression
Definition of the jPEG2000 Quality parameter in jPDFOptimizer
Q: How is the quality parameter defined when using JPEG2000 compression in jPDFOptimizer? This is the sample code I am using to compress existing images to JPEG2000 within PDF documents using jPDFOptimizer. imageoutput.setCompression(ImageOutput.CO_JPEG2000); imageoutput.setCompressionQuality(0.8f);imageoutput.setCompression(ImageOutput.CO_JPEG2000); imageoutput.setCompressionQuality(0.8f); The quality setting for JPEG200 compression is used to calculate the data rate (bits per pixel). The range for this […]
How to set the quality parameter when optimizing PDFs using JPEG or JPEG2000 compression
Q: We are using jPDFOptimizer, your Java library to optimize PDF documents. We are getting inconsistent results when compressing using JPEG2000 with the quality parameter. Sometimes the images are well compressed with a quality of 0.8, sometimes we have to use a quality of 0.2 for what appears to be the same results. A: This […]
Optimizing images in a PDF document: compression, color space and resolution
Qoppa’s 100% Java PDF optimizer library, jPDFOptimizer, allows, among other things, to change the properties of images in a PDF document including the compression, the color space, and the DPI resolution. This is done using the ImageHandler interface and implementing the convertImage() method which allows an application to define optimization option per image or per […]
