What version of InDesign? If you have InDesign CS5.5 or higher, select the chart and choose Object > Object Export Options, where you can set the resolution when the chart is rasterized for EPUB.
I use Indesign CC. I use Place to add the text, Then use Place to insert
the charts and anchor them to text in the area, center charts on page.
Display Performance - I use High Resolution. The chart are screenshot in
png. Before inserting the charts I convert the charts to jpeg in Photoshop
and save them to a file. I then Place the charts in InDesign. Save the
InDesign file. Exit the InDesign file and then reload the file. The chart
images are blurred. I go to Display Performance to change from Typical to
High Resolution. The chart images all change to High Resolution.
Everything looks good. I then export to ePub. I use Adobe Digital Edition
to view the ePub. The chart images are blurrred. I then run the Kindle
Previewer and the chart images are blurred there also.
How can I lock the chart images to high performance and have it maintain in
the epub file?
You have a pretty crazy workflow, and you're switching file formats multiple times. I'm sure it's the crazy workflow that's causing the resolution loss, but I can't really follow it. Where are the charts coming from? Are they originally vector (like AI from Illustrator) or rasterized?
Your confusion seems to lay with the "Display Performance" in InDesign.
InDesign's display performance is only important to InDesign.
When you place a file into InDesign it doesn't place the actual image. It creates a proxy (thumbnail) of the image to be viewed in the layout only.
InDesign links to files - to see the true resolution of an image you need to go the Window>Info and select the image and the information is visible in the Info panel.
InDesign comes with 3 flavours of preview of the thumbnails it creates, Fast, Typical and High - these 3 viewing settings are only to give you a flavour, Fast shows you a gray box and there's an image there, Typical shows a lo-res proxy, and High shows a high quality thumbnail version of your image.
These are not reflective of the true quality of the images.
All your images are PNG which are perfectly fine to place in InDesign - you are actually losing quality in your images by converting everything to JPEG - as JPEG is a lossy file format - where as PNG is lossless.
JPEG is much better for photographs (actual photos with lots of colour information)
PNG is much better for solid blocks of colour and for Charts, Diagrams, line Drawings, Screenshots - PNG is preferred over JPEG.
But all this changing to High Resolution in InDesign before Output does nothing reflective in the Output.
The true quality of your images lies in the Information within the file - which is visible on Window>Info
Maybe the workflow below will give you a better idea:
1. Open InDesign
2. Insert Word Document Text.
3. Insert Chart Images(jpeg) from picture folder and anchor them to
text area and center chart images on page
4. Chart Images – change typical to high resolution
5. Save InDesign File
6. Export InDesign File to create ePub file
7. View ePub in Adobe Digital Edition – Charts are blurred (lost high
resolution setting- maybe)
8. Run Kindle Previewer – Chart Images blurred (lost high resolution
If you have a better workflow or the above workflow is incorrect, please
indicate what I should be doing to correct the blurred image issue.
Thanks, I will try pgn format. I have converted a word document using the
charts to kindle. My only issue with ms word is i can't seem to anchor the
chart image to a centered area of the page. I thought I would use InDesign
because it seem to do a better job and there are more things I can do with