Course Presentation Canvas size?

Submitted by brigette_pusello on Tue, 05/01/2018 - 02:25
Forums: 
Content creation

Hi there, 

I have been making my own .png files (in photoshop) to use as backgrounds in H5P Course Presentation. Can you tell me if my images are being compressed when I insert them via the "Slide background" button in the tool bar at the bottom of the screen? They don't look as though they are, I am just curious.

I would like to know what is the maximum image resolution and maximum file size I can use in this format before they are compressed/resized (if this even happens at all?).

Hopefully you can understand my questions.

Thank you!

Brigette

 

Summary: 
Image resolution and image file size
Content types: 
Course Presentation
BV52's picture

BV52

Tue, 05/01/2018 - 04:37

Hi Brigette,

I had a quick look at the code and as far as I can see there's no limit to the resolution that you can use. What I found is that it stretches the image to fill the entire slide. I terms of file size this is only limited to the platform that you are using. If you are creating the contents in H5P.org the limit is 16 MB. If you are using one of the 3 plugins you are limited only by your settings. 

I hope this answers your question if you have further questions feel free to post in the forums.

-BV52

brigette_pusello

Wed, 05/02/2018 - 02:42

Hi there, 

Thanks for the response. I ended up testing 2 different image resolutions to see if they impacted file size, but there wasn't much difference in the H5P file size, is this normal?

I attempted 2 versions of the course Pres 

Image01 = 918 x 456px, 72ppi, 40kb. 

Image02 = 1680 x 1050px, 72ppi, 105kb.

Then I downloaded the two H5P files and they similar in size.

Course Pres 1 (17 slides of the same image): 2.33mb

Course Pres 2 (17 slides of the same image): 2.44mb 

H5P file: 
Binary Data test-1680x1050-image-233015 (1).h5p
Attachments: 
Binary Data test-918x456-image-233021 (2).h5p
BV52's picture

BV52

Wed, 05/02/2018 - 09:52

Hi brigette,

This seems to be normal ranges, since there really isn't much difference in the file size between the two images. The contents that you created can roughly be converted to:

CP 1 - 2330 kb

CP 2 - 2440 kb

Furthermore you shouldn't really worry much about file sizes when using images not unless the image is in png format.

-BV52 

brigette_pusello

Thu, 05/03/2018 - 00:40

Thanks for this information, 

Initially I expected that because the first CP contained images that were 1/4 of the size of those in CP 2 that I could expect the H5P file of CP2 to be 4 times as larges as the HP5 file of CP1.

I have been using PNGs in my H5P, why do I need to be worried about the file size of a PNG any differently to another image format say JPG? :)

Thanks for taking the time to explain this to me, it is very much appreciated. 

Brigette

BV52's picture

BV52

Thu, 05/03/2018 - 04:30

Hi Brigette,

PNGs usually are a lot larger in terms of file size compaired to JPGs. I've seen some PNGs that reach MBs specially for photographs. Although it is seldom that it would reach 16 MB which is the maximum upload limit for the site. Please note that the upload limit is per file that you upload so you don't have to take note of each file size if you are going to upload multiple images.

-BV52