I had added some information about texture size limitations to Elm image API reference.
OK then here:
If the image source size is bigger than maximum texture size of the GPU (or also of the software rendering code too), evas can't render it because of such a limitation. If evas just magically always downscales on load if it's too big, then the user has a new bug: "the image is blurry". Potentially any image can cause issue. What if the image is too big to allocate memory for it? A 30000x30000 image will need just a bit under 4GB of RAM to store it. Texture size limitations are something every game developer has to deal with game engines, OpenGL, D3D etc. You can get the maximum image size evas can possibly handle by the calling evas_image_max_size_get() function. If the image is bigger than this, you can try using load options to pre-scale down on load to lower quality. So use the elm_image_prescale_set() function to scale the image down. Another option is to use the Photocam widget. Photocam solves this issue by loading the prices as needed asynchronously in tiles and automatically using pre-scaling as well. So use Photocam if you expect to load very large images.
no problems. don't get me wrong. you are writing in a foreign language. if my korean was as good as your english... i'd be a very very very happy man! just wanting to help make the english in the docs more"native"... :)