Preparing the pictures

GraciousMe · 06-23-2012, 12:45 PM

The text for my book is ready, time to get the pictures in order. I use about 22 pictures and wonder how much I should standardize the proportions, file size and resolution (the same as DPI?).

The FILE-SIZE is between 8 kB (clipart) to 300 kB (JPG).

The PROPORTIONS vary. The pictures come from here and there, are compressed / resized without any clearer goal than to fit approximately into the 590 pixels wide x 750 pixels high-mold. (I don´t remember where I found those numbers.)

This is where I am most unsure. Should I try to have all or most pictures in the same size? Or are the following variations okay?

560 x 190
250 x 500
294 x 486
470 x 234
343 x 250
440 x 315
500 x 375
357 x 478
274 x 600
310 x 541
454 x 481
350 x 350
600 x 800
520 x 390
341 x 600
300 x 619
600 x 395
600 x 339
399 x 600
510 x 700
640 x 467

As to RESOLUTION, should I try to have the same with every picture? The majority are 150 x 150, a few 96 x 96, and there´s 73 x 73 for simple clipart.

Did I forget something important?

Toxaris · 06-23-2012, 12:53 PM

You can use any resolution you would like. I would pay more attention to the aspect ration. Please be aware that most readers have a resolution of roughly 600x800. It all depends on the effect you want to establish.

dwig · 06-23-2012, 01:10 PM

Quote:

Originally Posted by GraciousMe

...As to RESOLUTION, should I try to have the same with every picture? The majority are 150 x 150, a few 96 x 96, and there´s 73 x 73 for simple clipart.

PPI (aka DPI, though only PPI is correct) isn't an issue in an ebook, though it might be to whatever production tool you are using. You don't say what tool(s) you're using to create the ebook. Without that information nobody can give you reliable advise.

GraciousMe · 06-23-2012, 06:08 PM

Quote:

Originally Posted by dwig

PPI (aka DPI, though only PPI is correct) isn't an issue in an ebook, though it might be to whatever production tool you are using. You don't say what tool(s) you're using to create the ebook.

Sigil.

For the pictures, IrfanView and other simpler programs.

dwig · 06-23-2012, 10:07 PM

Quote:

Originally Posted by GraciousMe

Sigil.

For the pictures, IrfanView and other simpler programs.

Sigil is a true ebook editor. The PPI spec'd in the image's metadata is meaningless to Sigil. Ignore it. The image size in pixels is all that is important.

mrmikel · 06-24-2012, 07:34 AM

As has been said the choice is yours and depends on your audience.

If it is for tablets with big screens, the pictures can be bigger, otherwise 600x800. What you do want to avoid is stretching pictures out to fill the screen. The pictures will be blurry and unpleasant to look at. If they are smaller than the screen, leave them that way unless you have access to larger originals that you can resize to come closer to filling the screen.

If the pictures are smaller than screen width, you might want to give consideration to centering them. If they are maps or other image like your 560x190, you might give consideration to which way you want them displayed; shrink to fit the width or have your reader turn the machine sideways to get a full view. Again a judgement call.

If you have access to someone whose judgement you trust in your prospective audience, they might be a good source on these judgement calls. Academic users have entirely different imperatives than casual readers, for instance.

SBT · 06-25-2012, 05:03 AM

Unless the size of the epub file becomes unpleasantly large, I format the images for a 1200x1800, and then in the css file I give the individual image width as a percentage. Then the images are shown correctly whatever the resolution of the device.
If the epub file becomes too large, I reduces the image file sizes by:

Reducing the dimensions.
Reducing jpeg quality. For old photos and similar, 65% quality is sufficient.
Reduce number of colours in png drawings. For black and white illustrations, 16 grayscale levels are sufficient

06-23-2012, 12:45 PM	#1
GraciousMe Zealot Posts: 101 Karma: 202774 Join Date: Apr 2012 Device: none	Preparing the pictures The text for my book is ready, time to get the pictures in order. I use about 22 pictures and wonder how much I should standardize the proportions, file size and resolution (the same as DPI?). The FILE-SIZE is between 8 kB (clipart) to 300 kB (JPG). The PROPORTIONS vary. The pictures come from here and there, are compressed / resized without any clearer goal than to fit approximately into the 590 pixels wide x 750 pixels high-mold. (I don´t remember where I found those numbers.) This is where I am most unsure. Should I try to have all or most pictures in the same size? Or are the following variations okay? 560 x 190 250 x 500 294 x 486 470 x 234 343 x 250 440 x 315 500 x 375 357 x 478 274 x 600 310 x 541 454 x 481 350 x 350 600 x 800 520 x 390 341 x 600 300 x 619 600 x 395 600 x 339 399 x 600 510 x 700 640 x 467 As to RESOLUTION, should I try to have the same with every picture? The majority are 150 x 150, a few 96 x 96, and there´s 73 x 73 for simple clipart. Did I forget something important?

06-25-2012, 05:03 AM	#7
SBT Fanatic Posts: 580 Karma: 810184 Join Date: Sep 2010 Location: Norway Device: prs-t1, tablet, Nook Simple, assorted kindles, iPad	Unless the size of the epub file becomes unpleasantly large, I format the images for a 1200x1800, and then in the css file I give the individual image width as a percentage. Then the images are shown correctly whatever the resolution of the device. If the epub file becomes too large, I reduces the image file sizes by: Reducing the dimensions. Reducing jpeg quality. For old photos and similar, 65% quality is sufficient. Reduce number of colours in png drawings. For black and white illustrations, 16 grayscale levels are sufficient

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06-23-2012, 12:53 PM	#2
Toxaris Wizard Posts: 4,520 Karma: 121692313 Join Date: Oct 2009 Location: Heemskerk, NL Device: PRS-T1, Kobo Touch, Kobo Aura	You can use any resolution you would like. I would pay more attention to the aspect ration. Please be aware that most readers have a resolution of roughly 600x800. It all depends on the effect you want to establish.

06-24-2012, 07:34 AM	#6
mrmikel Color me gone Posts: 2,089 Karma: 1445295 Join Date: Apr 2008 Location: Central Oregon Coast Device: PRS-300	As has been said the choice is yours and depends on your audience. If it is for tablets with big screens, the pictures can be bigger, otherwise 600x800. What you do want to avoid is stretching pictures out to fill the screen. The pictures will be blurry and unpleasant to look at. If they are smaller than the screen, leave them that way unless you have access to larger originals that you can resize to come closer to filling the screen. If the pictures are smaller than screen width, you might want to give consideration to centering them. If they are maps or other image like your 560x190, you might give consideration to which way you want them displayed; shrink to fit the width or have your reader turn the machine sideways to get a full view. Again a judgement call. If you have access to someone whose judgement you trust in your prospective audience, they might be a good source on these judgement calls. Academic users have entirely different imperatives than casual readers, for instance.