Dropzone.js setting background pic - html

Question

I have an issue with Dropzone.js. I would like to insert a background image, on top of which people can drag and drop their own image. The funny thing is that I can set the background of the dropzone to any color I want (I tried blue) and it works, however it doesn't work for an image...
You can see in the following CSS code extract:
/* *****CHAMP DROPZONE***** */
.dropzone {
border: 1px solid #256EB8;
/*min-height: 360px;*/
height:70px;
width:70px;
-webkit-border-radius: 3px;
border-radius: 3px;
/*background: blue;*/
background-image: url("MY_IMAGE.png");
padding: 0px;
margin:0px;
}
Any idea of what is going wrong?
If needed, here is more of the code below :
/* The MIT License */
.dropzone,
.dropzone *,
.dropzone-previews,
.dropzone-previews * {
-webkit-box-sizing: border-box;
-moz-box-sizing: border-box;
box-sizing: border-box;
width:50%;
}
.dropzone {
position: relative;
/* border: 1px solid rgba(0,0,0,0.08);
background: rgba(0,0,0,0.02);
padding: 1em;*/
background-image: url("MY_IMAGE.png");
}
.dropzone .dz-message {
opacity: 1;
-ms-filter: none;
filter: none;
}
.dropzone.dz-drag-hover {
border-color: rgba(0,0,0,0.15);
background: rgba(0,0,0,0.04);
}
/* *****CHAMP CADRE BLANC***** */
.dropzone .dz-preview,
.dropzone-previews .dz-preview {
background: rgba(255,255,255,0.8);
position: relative;
display: inline-block;
margin: 0px;
vertical-align: top;
border: none;
padding: 0px 0px 0px 0px;
background-image: url("MY_IMAGE.png");
}
.dropzone .dz-preview.dz-file-preview [data-dz-thumbnail],
.dropzone-previews .dz-preview.dz-file-preview [data-dz-thumbnail] {
display: none;
}
/* *****CHAMP CADRE BLANC***** */
.dropzone .dz-preview .dz-details,
.dropzone-previews .dz-preview .dz-details {
width: 70px; /*******/
height: 70px; /*******/
position: relative;
background-image: url("MY_IMAGE.png");
/*background: #ebebeb;********************************/
padding: 0px;
margin-bottom: 0px;
}
.dropzone .dz-preview .dz-details .dz-filename,
.dropzone-previews .dz-preview .dz-details .dz-filename {
overflow: hidden;
height: 100%;
}
/* *****CHAMP IMAGE UPLOADEE***** */
.dropzone .dz-preview .dz-details img,
.dropzone-previews .dz-preview .dz-details img {
position: absolute;
top: 0;
left: 0;
width: 70px; /*******/
height: 70px; /*******/
-webkit-border-radius: 3px;
border-radius: 3px;
}
/* *****CHAMP DROPZONE***** */
.dropzone {
border: 1px solid #256EB8;
/*min-height: 360px;*/
height:70px;
width:70px;
-webkit-border-radius: 3px;
border-radius: 3px;
/*background: blue;*/
background-image: url("MY_IMAGE.png");
padding: 0px;
margin:0px;
}
/* *****CHAMP DROPZONE MESSAGE ACCUEIL***** */
.dropzone .dz-default.dz-message {
opacity: 1;
-ms-filter: none;
filter: none;
-webkit-transition: opacity 0.3s ease-in-out;
-moz-transition: opacity 0.3s ease-in-out;
-o-transition: opacity 0.3s ease-in-out;
-ms-transition: opacity 0.3s ease-in-out;
transition: opacity 0.3s ease-in-out;
/*background-image: url("../images/spritemap.png");*/
/*background-image: none;*/
background-image: url("MY_IMAGE.png");
/*background-repeat: no-repeat;
background-position: 0 0;*/
position: absolute;
width: 70px; /*******/
height: 70px; /*******/
/*margin-left: -214px;
margin-top: -61.5px;
top: 50%;
left: 50%;*/
}
#media all and (-webkit-min-device-pixel-ratio:1.5),(min--moz-device-pixel-ratio:1.5),(-o-min-device-pixel-ratio:1.5/1),(min-device-pixel-ratio:1.5),(min-resolution:138dpi),(min-resolution:1.5dppx) {
.dropzone .dz-default.dz-message {
background-image: url("MY_IMAGE.png");
-webkit-background-size: 428px 406px;
-moz-background-size: 428px 406px;
background-size: 428px 406px;
}
}
.dropzone .dz-default.dz-message span {
display: none;
}
/*
.dropzone.dz-square .dz-default.dz-message {
background-position: 0 -123px;
width: 268px;
margin-left: -134px;
height: 174px;
margin-top: -87px;
}
.dropzone.dz-drag-hover .dz-message {
opacity: 0.15;
-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=15)";
filter: alpha(opacity=15);
}
.dropzone.dz-started .dz-message {
display: block;
opacity: 0;
-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";
filter: alpha(opacity=0);
}*/
/*.dropzone .dz-preview,
.dropzone-previews .dz-preview {
-webkit-box-shadow: 1px 1px 4px rgba(0,0,0,0.16);
box-shadow: 1px 1px 4px rgba(0,0,0,0.16);
font-size: 14px;
}*/
Thank you for your help!
Paul

Answer 1

The easiest solution I think is to add to your custom css file following code
.dropzone .dz-preview.dz-image-preview {
background-color: transparent !important;
}
This will help especially when you have dropzone's css file linked via cdn.

Answer 2

GOT IT!
The image was not located in a folder relative to the CSS file.
I changed the background image url the following way :
/* *****CHAMP DROPZONE***** */
.dropzone {
border: 1px solid #256EB8;
/*min-height: 360px;*/
height:70px;
width:70px;
-webkit-border-radius: 3px;
border-radius: 3px;
/*background: blue;*/
background-image: url("../images/MY_IMAGE.png");
padding: 0px;
margin:0px;
}