how to change the size of an image in illustrator

How can I solve this problem as I want to size a photo and 'place' it into illustartor at the correct size and at 300dpi so that I can print it! 900px x 900px, the resolution starts to decrease and do so drastically! However what actually happens is the 'placed' image appears but is over four times smaller in illustrator!! In itself this isn't a problem but then when I scale it up to the size I want e.g. Now I would expect the 'placed' jpeg to cover the entire artboard in illustrator because the jpeg is 900px x 900px and so is the artboard. I then opened an illustrator document setup to 900px x 900px at 300ppi and 'placed' the red jpeg I had just created in photoshop into illustrator. I then saved this image as a jpeg so the jpeg had a dimension of 900px x 900px. To give an example I just created a photoshop canvas of 900px x 900px with a resolution of 300ppi and filled it with a red colour. Be aware to keep an eye on your Links panel (Window>Links) to make sure the resolution doesnt get too low as you make the image bigger.Hi when i size an image in photoshop and then 'place' it in illustrator the 'placed' image is way smaller in illustrator than in photoshop. Both the frame and the image will now be stuck together and you can drag it as big or as small as you like.

Ok so this is the best way to have complete control, you can just hold down the Ctrl (Command on Mac) then also hold down the Shift key then simply grab the corner handle on your Adobe InDesign frame and drag it. This will scale proportionally it wont stretch your image at all so you can then use the hotspot to adjust which part of the image is visible in the Adobe InDesign frame.

then we are going to select the frame and look in to our InDesign Control bar at the top of the screen where there is a button that will scale the content of the frame to fit the frame. The first way is to use your main selection tool to make the frame the correct size that you want, dont worry about the image not moving with the frame just make the frame fit the space you require on the Adobe InDesign page.

How to change the size of an image in illustrator