kindle azw to PocektBook epub images too small

[JSWolf]

Originally Posted by richo

Thank for tip, but why does the description of Tablet profile says:

does no resizing of images

Wouldn’t this means it will not do what I like to have. Bigger images on high resolution screen?

What this means is that the images in the source file will stay the same size as they are originally. If the images are small, it's because they are small in the source file. You can change the code in the ePub to have the images sized to be larger. For example, you can have the images displayed full screen. But, depending on the resolution of the images and the resolution of your screen, you can get fuzzy images.

The blame lies with the publisher for publishing low resolution images.

[richo]

Originally Posted by JSWolf

You can change the code in the ePub to have the images sized to be larger. For example, you can have the images displayed full screen.

Can you suggest how? Thank you in advance.

[JSWolf]

Originally Posted by richo

Can you suggest how? Thank you in advance.

Can you post a sample of the code that displays images and the relevant CSS? Thanks.

[BetterRed]

@richo - maybe you could use the Unpack tool on the ePub. You will probably need to add Unpack to a toolbar or menu. Explode the book (the tool will put the components into a temporary location), use an image editor to upscale, sharpen ... the images, and then Rebuild the book.

I found an image about the same size as the ones you have (400x200), and I resized it to 1200x1600 using Lancoz resampling. The two images are attached.

If there were a more than a handful of images, and they were 'important' - e.g. if it was a cook book or a travelogue I would wince whenever I saw the resized images on a tablet.

I would even consider looking for an epub edition with larger images and get calibre to convert to a Kindle PW compatible format with downscaled images.

BR

[JSWolf]

And with the resampled image, it's blurry and has very noticeable compression artifacts.

[BetterRed]

Originally Posted by JSWolf

And with the resampled image, it's blurry and has very noticeable compression artifacts.

Dumb question - If my Amazon registered device was a Fire 10 tablet would Amazon supply a book with bigger images ?

BR

[richo]

Originally Posted by JSWolf

Can you post a sample of the code that displays images and the relevant CSS? Thanks.

Take a look to post #6 in this thread please:

[richo]

Originally Posted by BetterRed

@richo - maybe you could use the Unpack tool on the ePub. You will probably need to add Unpack to a toolbar or menu. Explode the book (the tool will put the components into a temporary location), use an image editor to upscale, sharpen ... the images, and then Rebuild the book.

Thank you for the suggestion. I have never heard about the Unpack. Is it plug-in for calibre? I used calibre ebook editor to enlarge them 2x manually two images and sharpen them. This gave me nice images (these are actually hand drawing and therefore they do scale pretty OK).

Then I also need to modify CSS produced by calibre for each image containing width, height. There are few hundred images in this book. That is a reason I was looking for some way I can automatize this process.

[richo]

Originally Posted by BetterRed

Dumb question - If my Amazon registered device was a Fire 10 tablet would Amazon supply a book with bigger images ?

BR

This is interesting question which would solve me issue as I bought this book from Amazon, I however do not own high resolution Kindle.

[theducks]

Originally Posted by richo

Are you saying that Calibre is never going to remove own calibre styles where width and high is defined and is also not going to upscale images to use higher resolution of the e-reader chosen from profile?

If that is true I wonder why there are these profiles in Calibre at all?

Have you seen an image that was blown UP BIGGER? CR*P
It takes sophisticated image processing to 'fake in the space' between known pixels.

[richo]

Originally Posted by theducks

Have you seen an image that was blown UP BIGGER? CR*P
It takes sophisticated image processing to 'fake in the space' between known pixels.

Yes, after 30 years in professional photography I do. That is however not a point I try to solve here.

[richo]

To illustrate original look of the page and when I double the dimension manually I am attaching two files.

[kovidgoyal]

calibre never produces CSS. If a width declaration for an image is there in an output document it is there becaause it was in the input document, or the output document requires it. If you want to automate removal of width and height declaration use the Transform Styles tool in the Look & Feel section of the conversion dialog. Create a rule that delete width if its value is greater than 10 and similar of height.

[DoctorOhh]

Originally Posted by richo

This is interesting question which would solve me issue as I bought this book from Amazon, I however do not own high resolution Kindle.

The answer is no. If that was the case simply downloading to your Kindle for PC would give you the highest resolution images. Amazon delivers whatever the publisher gives them.

If the publisher is really concerned about images I would guess they would use a high resolution image and give it a width attribute with a 50% (or what ever is appropriate) setting so the image would always stretch or shrink to 50% of the screen. I don't recall, but I believe the issue with this was some early E-ink readers choked on larger images or may not have supported the width attribute for images.