Size of modified picture in iOS: Modify resolution and cropping

In the development of iOS, there are often limited image file size, some users picture is very large, resulting in slow upload time, causing problems.

such as: sharing, if the size of the picture appears to be greater than 50kbytes, sharing failed, and no hint.

So, I added two functions:

First, change the size of the current picture, newsize is a new size size, this method to help users get to a smaller picture.

But this newsize size proposal is the same as the original, otherwise the picture will be deformed.

-(UIImage*) Imagewithimagesimple: (UIImage*) image scaledtosize: (cgsize) newSize

{

//Create A graphics image context

uigraphicsbeginimagecontext(newSize);

//Tell the old image to draw in this new context, with the desired

//New size

[Image Drawinrect:cgrectmake(0,0, newSize. Width, newSize. Height)];

//Get The new image from the context

UIImage* newimage = uigraphicsgetimagefromcurrentimagecontext();

//End the context

Uigraphicsendimagecontext();

//Return the new image.

return newimage;

}

Second, the function, realizes the user wants to intercept the graph the rect

-(UIImage *) Getimagebycuttingimage: (UIImage *) image Rect: (cgrect) rect{

// big picture bigimage

// define Thearea of the myimagerect

cgrect myimagerect = rect;

UIImage* bigimage= image;

cgimageref imageref = bigimage. Cgimage;

cgimageref subimageref = cgimagecreatewithimageinrect(Imageref, myimagerect);

cgsize size;

Size. width = rect.size. width;

Size. height = rect.size. Height;

uigraphicsbeginimagecontext(size);

cgcontextref context = uigraphicsgetcurrentcontext();

cgcontextdrawimage(context, myimagerect, subimageref);

UIImage* smallimage = [UIImage imagewithcgimage: subimageref];

Uigraphicsendimagecontext();

return smallimage;

}

Size of modified picture in iOS: Modify resolution and cropping