Image resizing is very important for organizing Blog content. If we just add image without any organized way then the Blog post won't look very attractive. Suppose if you add an wide landscape image without any resizing then your Blog Post image may go outside or the margin. So in this case we can resize image easily without any help of Photo Editing software. Some Blogger tweak their Blog Image for maintaining higher resolution. First they upload an large image and then resize then into large or medium size. This strategy works great and Image will be more clear. But if you upload an small image and resize it to large or Ex-large then your image quality will be inferior. Because of lower resolution image will become blur or hazy. So we should always add bit larger image than actual image which we will resize on our Blog's post editor manually. Anyway Just follow the below steps for resizing an Blog post image easily.
Step 1 Log in to your Blogger Account and Go to your Blogger Dashboard
Step 2 Click on Now click on -> New post and Upload an image.
Step 3 Now Click on Image from Blogger Post editor. A popup image Toolbar will visible.
Step 4 You will see 4 option at the left of the toolbar Small, Medium, Large, X-Large and Original size link.
Step 5 Now click on any option Small or Medium or Large or X-Large you will see the size is changing on Blogger post Editor panel. So select appropriate one that fit your post. And finally Publish your post.
So that's all about resizing image in Blogger Blog post. However if you use Photo Editing software then you can resize image first and then upload it. In that case select Original size link thus your image can display original size. In my Blog I have created a featured image layout which will be same size 600px width and 200px height. For this reason whenever I add this image then I choose Original size link. Though my Blog's content wrapper width is 800px for this reason I can use more width image here. I hope you will now easily resize image without any hindrance.