Blurred images in A4 but not in letter paper size

[kerimucci]

Hello,

I am converting all of my PDFs over to A4. I previously used letter size.

I've set up my page layouts which look great, however, every image within my topics is blurred when I apply the new page layout to the target. If I change it back to letter, the images are fine. All images are PNGs. I attached a screenshot of the same image pubbed to both paper sizes.

I opened a ticket with Flare Support previously and was told the difference was not that noticeable, but to me it is, and I cannot figure out why the images would be blurred when using the new page layouts. The only time I have issues with blurred images in PDF is when they are wider than the max-width property I set to keep them within the margins, and these images are smaller anyway. I turned the target's "Downsample images above" setting on and that doesn't make a difference.

Has anyone else experienced this? I need to make my entire documentation set use the A4 page layouts, so I would like these images to appear as they should. Is there a setting I need to disable or enable?

[SteveS]

Have you set image size using percentage?

This could lead to low quality resizing.

If you have, try setting image size using a physical size, like 550 pixels to cover a page width.

[robdocsmith]

Hi,

Is the text frame on your A4 layout narrower than the corresponding frame on the letter layout? I suspect it's to do with the rescaling of the image when it goes to print. I try to avoid that where possible by pre-sizing my images to suit the locations outside of Flare. My columns are 90mm so I make my images multiples of that depending on whether they span one, two or three columns. And I try to avoid downsampling resolution inside Flare and have the images set to my preferred resolution in source. But it's harder to manage if you are single sourcing and producing for an online format as well, where the images may need to be larger to be seen.

Rob

[kerimucci]

Thanks, guys.

So my images are set to a max-width of 670px and a max-height of auto.

For A4, my page layout's body frame is set to a width of 674px. For letter, my page layout is set to 624px, so the body frame is actually larger now. I would think if anything this would help my images look crisper, as I only noticed blurriness before when the image was much larger than the page.

I only use one column, and will be single sourcing this to be HTML output as well next month.

Any more thoughts?

[robdocsmith]

What are the actual dimensions of the picture and how do they compare to the 674px or 624px? You can hover your mouse over an image in Windows to see the size quickly. Are they a simple multiple or some other fraction?
Rob

[kerimucci]

Most of my images are smaller than 670px in width, which is what I've set for the max-width property.

I am not really sure what you mean by simple multiple vs fraction. For example, one says 400 x 229 when I hover over it.

[robdocsmith]

If the dimensions of an image are smaller (or larger) than the frame in which they are placed, and css allows it, the image will be resized to fit. If your page frame was 600px wide and the image a multiple or fraction of that (300px, 600px, 1200px, etc) you're likely to get less blurring (particularly if it was an exact fraction). It's easier to determine what colour a resized pixel would be. This shows most on colour boundaries of objects in an image. This is why blurring of edges occurs. For example, when resizing Flare tries to work out at the boundary of a black object on a white background whether the resized pixel should be black, white or some shade of grey depending on how many pixels it has to go on from the original. My tips are:

• Try to resize images in a proper image edition program and outside of Word, Flare, other typesetting application.
• Use bicubic resampling for resizing screen shots.
• For screen captures, try to avoid Jpgs which is a lossy file format and use a lossless format like png instead.
• Try to avoid using max or min width/height in your image css. It will mean you're not in control of what the final image size will be in print and can lead to resizing/blurring.
• Resize an image to optimize print output (size it for the text frame and print resolution)
• Try using target conditions with multiple sizes of images in your source if you are having difficulty choosing a suitable size/scale for all outputs (one image for print, one for online etc).